feat(github): implement FileReader interface (#80)

Implement FileReader conformance on the GitHub client: GetFileContent,
ListContents, path helpers, base64 decode. Includes compile-time
conformance checks for both PRReader and FileReader.

Requires PR B (#102). Part 3 of 3 for #80.

.gitea/actions/review/action.yml

@@ -1,43 +1,17 @@
-# This composite action supports both Gitea Actions and GitHub Actions runners.
+# This composite action is designed for Gitea Actions runners.
-# It detects the VCS host type by checking whether github.api_url is set
+# Gitea Actions supports GitHub Actions syntax including $GITHUB_OUTPUT,
-# (present on GitHub.com and GHES runners, absent on Gitea runners) and uses
+# actions/cache, and actions/checkout.
-# the appropriate releases API for version resolution and binary download
-# (REST API on GitHub, direct URLs on Gitea).
-#
-# Security notes:
-# - On GitHub/GHES (VCS_TYPE=github), inputs.vcs-url is IGNORED to prevent
-#   token exfiltration. API calls use github.api_url; downloads use
-#   github.server_url. Tokens are never sent to user-supplied URLs.
-# - On Gitea (VCS_TYPE=gitea), inputs.vcs-url is validated (https scheme,
-#   no whitespace/newlines, and DNS resolution to a public IP) before use.
-#   Python3 resolves the hostname and rejects RFC1918, RFC6598 (carrier-grade
-#   NAT), loopback, link-local, and other reserved addresses to prevent SSRF attacks.
-#   The installed review-bot binary additionally uses a safe HTTP transport
-#   (DialContext-level IP check) for all Gitea API calls at runtime.
-#   The binary also exposes a `validate-url` subcommand for use in any future
-#   shell steps that need to validate a URL before passing it to curl.
-# - action-repo is validated against owner/repo pattern.
-# - Tokens are passed via masked environment variables, not step outputs.
-#
 # Requirements: python3, sha256sum, curl (all present on ubuntu-* runners).
 name: 'AI Code Review'
 description: 'Run AI-powered code review on a pull request using review-bot'
 
 inputs:
-  vcs-url:
+  gitea-url:
-    description: 'VCS server URL (only used on Gitea runners; ignored on GitHub/GHES). Defaults to server_url.'
+    description: 'Gitea instance URL (defaults to server_url)'
     required: false
     default: ''
   repo:
-    description: 'Repository to review (owner/name, defaults to current)'
+    description: 'Repository (owner/name, defaults to current)'
-    required: false
-    default: ''
-  action-repo:
-    description: 'Repository hosting review-bot releases (owner/name). Defaults to github.action_repository or rodin/review-bot.'
-    required: false
-    default: ''
-  action-repo-token:
-    description: 'Token for downloading release assets from action-repo (defaults to github.token on GitHub, reviewer-token on Gitea). Required for private repos.'
     required: false
     default: ''
   pr-number:
@@ -45,7 +19,7 @@ inputs:
     required: false
     default: ''
   reviewer-token:
-    description: 'Token for posting the review'
+    description: 'Gitea token for posting the review'
     required: true
   reviewer-name:
     description: 'Display name for the reviewer'
@@ -138,325 +112,45 @@ runs:
       id: version
       shell: bash
       run: |
-        set -euo pipefail
+        GITEA_URL="${{ inputs.gitea-url || github.server_url }}"
-
+        REPO="${{ inputs.repo || 'rodin/review-bot' }}"
-        # --- Input Validation ---
-
-        # Determine the repo hosting review-bot releases (not the repo being reviewed)
-        ACTION_REPO="${{ inputs.action-repo }}"
-        if [ -z "$ACTION_REPO" ]; then
-          # github.action_repository is the repo containing the running action
-          ACTION_REPO="${{ github.action_repository }}"
-        fi
-        if [ -z "$ACTION_REPO" ]; then
-          # Final fallback for Gitea (which may not set action_repository)
-          ACTION_REPO="rodin/review-bot"
-          echo "::notice::action-repo not specified and github.action_repository is empty; falling back to rodin/review-bot"
-        fi
-
-        # Validate ACTION_REPO matches owner/repo pattern (prevent path traversal)
-        if ! printf '%s' "$ACTION_REPO" | grep -qE '^[a-zA-Z0-9._-]+/[a-zA-Z0-9._-]+$'; then
-          echo "Error: action-repo '${ACTION_REPO}' does not match expected owner/repo format" >&2
-          exit 1
-        fi
-
-        # Detect VCS host type using github.api_url context.
-        # github.api_url is set on GitHub.com (https://api.github.com) and GHES
-        # (https://<host>/api/v3). It is empty/unset on Gitea Actions runners.
-        GITHUB_API_URL="${{ github.api_url }}"
-        if [ -n "$GITHUB_API_URL" ]; then
-          VCS_TYPE="github"
-        else
-          VCS_TYPE="gitea"
-        fi
-
-        # Determine SERVER_URL based on VCS type.
-        # SECURITY: On GitHub/GHES, ALWAYS use github.server_url — never trust
-        # inputs.vcs-url to prevent token exfiltration to attacker-controlled hosts.
-        if [ "$VCS_TYPE" = "github" ]; then
-          SERVER_URL="${{ github.server_url }}"
-          if [ -n "${{ inputs.vcs-url }}" ]; then
-            echo "::warning::inputs.vcs-url is ignored on GitHub/GHES runners (VCS_TYPE=github). Using github.server_url instead."
-          fi
-        else
-          SERVER_URL="${{ inputs.vcs-url || github.server_url }}"
-        fi
-        # Strip trailing slash if present
-        SERVER_URL="${SERVER_URL%/}"
-
-        # Validate SERVER_URL for Gitea path: must be https, no whitespace/newlines.
-        # The [^[:space:]] class already rejects newlines, so no separate newline check needed.
-        if [ "$VCS_TYPE" = "gitea" ]; then
-          if ! printf '%s' "$SERVER_URL" | grep -qE '^https://[^[:space:]]+$'; then
-            echo "Error: SERVER_URL '${SERVER_URL}' must be an https:// URL with no whitespace" >&2
-            exit 1
-          fi
-
-          # Additional IP-level SSRF defense: resolve the hostname and reject
-          # requests to RFC1918, RFC6598 (carrier-grade NAT), loopback, link-local,
-          # and other reserved addresses.
-          # python3 is required on ubuntu-* runners (see requirements comment above).
-          # Use printf to write the script to a temp file so the python lines are valid
-          # YAML (each indented line becomes a printf argument — no unindented code).
-          # SERVER_URL is passed via CHECK_URL env var, never interpolated into python code.
-          printf '%s\n' \
-            'import socket,ipaddress,sys,os' \
-            'from urllib.parse import urlparse' \
-            'u=os.environ["CHECK_URL"]; parsed=urlparse(u)' \
-            'if parsed.username or parsed.password:' \
-            '  print("Error: URL contains user-info — not allowed",file=sys.stderr); sys.exit(2)' \
-            'h=parsed.hostname' \
-            '(print("Error: no hostname",file=sys.stderr) or sys.exit(2)) if not h else None' \
-            'try: rs=socket.getaddrinfo(h,None)' \
-            'except socket.gaierror as e: print(f"DNS error: {e}",file=sys.stderr); sys.exit(1)' \
-            'if not rs: print("Error: no addresses",file=sys.stderr); sys.exit(1)' \
-            'for _,_,_,_,(a,*_) in rs:' \
-            '  ip=ipaddress.ip_address(a)' \
-            '  if isinstance(ip,ipaddress.IPv6Address) and ip.ipv4_mapped: ip=ip.ipv4_mapped' \
-            '  cgn=ipaddress.ip_network("100.64.0.0/10")' \
-            '  if ip.is_private or ip.is_loopback or ip.is_link_local or ip.is_multicast or ip.is_reserved or ip in cgn:' \
-            '    print(f"blocked: {a}",file=sys.stderr); sys.exit(1)' \
-            > /tmp/_ssrf_check.py
-          CHECK_URL="${SERVER_URL}" python3 /tmp/_ssrf_check.py || {
-            echo "Error: SERVER_URL '${SERVER_URL}' resolves to a private/reserved IP address" >&2
-            exit 1
-          }
-        fi
-
-        # Determine auth token for release API requests
-        ACTION_TOKEN="${{ inputs.action-repo-token }}"
-        if [ -z "$ACTION_TOKEN" ]; then
-          if [ "$VCS_TYPE" = "github" ]; then
-            ACTION_TOKEN="${{ github.token }}"
-          else
-            ACTION_TOKEN="${{ inputs.reviewer-token }}"
-          fi
-        fi
-
-        # Validate token contains no control characters (defense-in-depth against header injection)
-        if [ -n "$ACTION_TOKEN" ]; then
-          if printf '%s' "$ACTION_TOKEN" | LC_ALL=C grep -q '[^[:print:]]'; then
-            echo "Error: ACTION_TOKEN contains control characters" >&2
-            exit 1
-          fi
-        fi
-
         if [ "${{ inputs.version }}" = "latest" ]; then
-          if [ "$VCS_TYPE" = "github" ]; then
+          VERSION=$(curl -sSf "${GITEA_URL}/api/v1/repos/${REPO}/releases?limit=1" \
-            # SECURITY: Use github.api_url which is a trusted platform-provided value.
-            # Never construct API URLs from user-supplied inputs on GitHub.
-            API_URL="${GITHUB_API_URL}/repos/${ACTION_REPO}/releases?per_page=1"
-          else
-            # Gitea API — SERVER_URL was validated above
-            API_URL="${SERVER_URL}/api/v1/repos/${ACTION_REPO}/releases?limit=1"
-          fi
-
-          # Fetch latest version with inline auth header (no intermediate variable)
-          if [ -n "$ACTION_TOKEN" ]; then
-            if [ "$VCS_TYPE" = "github" ]; then
-              VERSION=$(curl -sSf --connect-timeout 10 --max-time 30 \
-                -H "Authorization: Bearer ${ACTION_TOKEN}" "$API_URL" \
             | python3 -c "import sys, json; releases = json.load(sys.stdin); print(releases[0]['tag_name'] if releases else '')")
-            else
-              VERSION=$(curl -sSf --connect-timeout 10 --max-time 30 \
-                -H "Authorization: token ${ACTION_TOKEN}" "$API_URL" \
-                | python3 -c "import sys, json; releases = json.load(sys.stdin); print(releases[0]['tag_name'] if releases else '')")
-            fi
-          else
-            VERSION=$(curl -sSf --connect-timeout 10 --max-time 30 "$API_URL" \
-              | python3 -c "import sys, json; releases = json.load(sys.stdin); print(releases[0]['tag_name'] if releases else '')")
-          fi
-
           if [ -z "$VERSION" ]; then
-            echo "Failed to determine latest version from ${API_URL}" >&2
+            echo "Failed to determine latest version" >&2
             exit 1
           fi
         else
           VERSION="${{ inputs.version }}"
         fi
-
-        # Validate VERSION: no slashes or whitespace (prevent path traversal).
-        # [:space:] includes newlines and carriage returns in POSIX.
-        if printf '%s' "$VERSION" | grep -qE '[/[:space:]]'; then
-          echo "Error: VERSION '${VERSION}' contains invalid characters (newline, slash, or whitespace)" >&2
-          exit 1
-        fi
-
-        # Detect OS and architecture for platform-specific binary download
-        OS_RAW=$(uname -s | tr '[:upper:]' '[:lower:]')
-        case "$OS_RAW" in
-          linux)  OS="linux" ;;
-          darwin) OS="darwin" ;;
-          *)
-            echo "Error: unsupported OS: $(uname -s)" >&2
-            exit 1
-            ;;
-        esac
-
-        RAW_ARCH=$(uname -m)
-        case "$RAW_ARCH" in
-          x86_64)           ARCH="amd64" ;;
-          aarch64 | arm64)  ARCH="arm64" ;;
-          *)
-            echo "Error: unsupported architecture: $RAW_ARCH" >&2
-            exit 1
-            ;;
-        esac
-
         echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
-        echo "os=${OS}" >> "$GITHUB_OUTPUT"
-        echo "arch=${ARCH}" >> "$GITHUB_OUTPUT"
-        echo "action_repo=${ACTION_REPO}" >> "$GITHUB_OUTPUT"
-        echo "server_url=${SERVER_URL}" >> "$GITHUB_OUTPUT"
-        echo "vcs_type=${VCS_TYPE}" >> "$GITHUB_OUTPUT"
-
-        # SECURITY: Pass token via masked environment variable instead of step output.
-        # Step outputs can leak in debug logs; GITHUB_ENV with masking is safer.
-        if [ -n "$ACTION_TOKEN" ]; then
-          echo "::add-mask::${ACTION_TOKEN}"
-          echo "ACTION_TOKEN=${ACTION_TOKEN}" >> "$GITHUB_ENV"
-        fi
 
     - name: Cache review-bot binary
       id: cache
       uses: actions/cache@v4
       with:
         path: ${{ runner.temp }}/review-bot
-        key: review-bot-${{ steps.version.outputs.os }}-${{ steps.version.outputs.arch }}-${{ steps.version.outputs.version }}
+        key: review-bot-linux-amd64-${{ steps.version.outputs.version }}
 
     - name: Install review-bot
       if: steps.cache.outputs.cache-hit != 'true'
       shell: bash
       run: |
-        set -euo pipefail
+        GITEA_URL="${{ inputs.gitea-url || github.server_url }}"
-
+        REPO="${{ inputs.repo || 'rodin/review-bot' }}"
-        SERVER_URL="${{ steps.version.outputs.server_url }}"
-        ACTION_REPO="${{ steps.version.outputs.action_repo }}"
         VERSION="${{ steps.version.outputs.version }}"
-        VCS_TYPE="${{ steps.version.outputs.vcs_type }}"
+        BINARY="review-bot-linux-amd64"
-        OS="${{ steps.version.outputs.os }}"
-        ARCH="${{ steps.version.outputs.arch }}"
-        # Read token from masked environment variable (set in Determine version step)
-        # Falls back to empty if not set (public repos don't need auth)
-        ACTION_TOKEN="${ACTION_TOKEN:-}"
-        BINARY="review-bot-${OS}-${ARCH}"
 
-        # SECURITY: Re-validate SERVER_URL at the start of this step to mitigate DNS
+        curl -sSfL "${GITEA_URL}/${REPO}/releases/download/${VERSION}/${BINARY}" \
-        # rebinding attacks. A DNS TTL expiry between "Determine version" and here
-        # could allow an attacker to change the resolved IP to a private/reserved
-        # address, causing curl to send ACTION_TOKEN to an internal host.
-        # Only needed on Gitea path (VCS_TYPE=gitea); GitHub/GHES uses platform-controlled URLs.
-        if [ "$VCS_TYPE" = "gitea" ]; then
-          printf '%s\n' \
-            'import socket,ipaddress,sys,os' \
-            'from urllib.parse import urlparse' \
-            'u=os.environ["CHECK_URL"]; parsed=urlparse(u)' \
-            'if parsed.username or parsed.password:' \
-            '  print("Error: URL contains user-info — not allowed",file=sys.stderr); sys.exit(2)' \
-            'h=parsed.hostname' \
-            '(print("Error: no hostname",file=sys.stderr) or sys.exit(2)) if not h else None' \
-            'try: rs=socket.getaddrinfo(h,None)' \
-            'except socket.gaierror as e: print(f"DNS error: {e}",file=sys.stderr); sys.exit(1)' \
-            'if not rs: print("Error: no addresses",file=sys.stderr); sys.exit(1)' \
-            'for _,_,_,_,(a,*_) in rs:' \
-            '  ip=ipaddress.ip_address(a)' \
-            '  if isinstance(ip,ipaddress.IPv6Address) and ip.ipv4_mapped: ip=ip.ipv4_mapped' \
-            '  cgn=ipaddress.ip_network("100.64.0.0/10")' \
-            '  if ip.is_private or ip.is_loopback or ip.is_link_local or ip.is_multicast or ip.is_reserved or ip in cgn:' \
-            '    print(f"blocked: {a}",file=sys.stderr); sys.exit(1)' \
-              > /tmp/_ssrf_check_install.py
-          CHECK_URL="${SERVER_URL}" python3 /tmp/_ssrf_check_install.py || {
-            echo "Error: SERVER_URL '${SERVER_URL}' resolves to a private/reserved IP address" >&2
-            exit 1
-          }
-        fi
-
-        if [ "$VCS_TYPE" = "github" ]; then
-          # GitHub/GHES: Use REST API for release asset downloads.
-          # Web release URLs ({server}/.../releases/download/{tag}/{asset}) redirect
-          # to S3 and don't reliably support Authorization headers for private repos.
-          # The REST API endpoint with Accept: application/octet-stream is required.
-          # GITHUB_API_URL: trusted platform value, same as detected in "Determine version" step.
-          GITHUB_API_URL="${{ github.api_url }}"
-
-          if [ -n "$ACTION_TOKEN" ]; then
-            RELEASE_JSON=$(curl -sSf --connect-timeout 10 --max-time 30 \
-              -H "Authorization: Bearer ${ACTION_TOKEN}" \
-              "${GITHUB_API_URL}/repos/${ACTION_REPO}/releases/tags/${VERSION}")
-          else
-            RELEASE_JSON=$(curl -sSf --connect-timeout 10 --max-time 30 \
-              "${GITHUB_API_URL}/repos/${ACTION_REPO}/releases/tags/${VERSION}")
-          fi
-
-          # Extract asset IDs for binary and checksums
-          BINARY_ASSET_ID=$(printf '%s' "$RELEASE_JSON" | python3 -c "import sys, json; assets = json.load(sys.stdin).get('assets', []); matches = [a['id'] for a in assets if a['name'] == '${BINARY}']; print(matches[0] if matches else '')")
-          if [ -z "$BINARY_ASSET_ID" ]; then
-            echo "Error: could not find asset '${BINARY}' in release ${VERSION}" >&2
-            exit 1
-          fi
-
-          CHECKSUMS_ASSET_ID=$(printf '%s' "$RELEASE_JSON" | python3 -c "import sys, json; assets = json.load(sys.stdin).get('assets', []); matches = [a['id'] for a in assets if a['name'] == 'checksums.txt']; print(matches[0] if matches else '')")
-          if [ -z "$CHECKSUMS_ASSET_ID" ]; then
-            echo "Error: could not find asset 'checksums.txt' in release ${VERSION}" >&2
-            exit 1
-          fi
-
-          # Download assets via REST API with Accept: application/octet-stream
-          if [ -n "$ACTION_TOKEN" ]; then
-            curl -sSfL --connect-timeout 10 --max-time 120 \
-              -H "Authorization: Bearer ${ACTION_TOKEN}" \
-              -H "Accept: application/octet-stream" \
-              "${GITHUB_API_URL}/repos/${ACTION_REPO}/releases/assets/${BINARY_ASSET_ID}" \
           -o "${{ runner.temp }}/review-bot"
-            curl -sSfL --connect-timeout 10 --max-time 30 \
+        curl -sSfL "${GITEA_URL}/${REPO}/releases/download/${VERSION}/checksums.txt" \
-              -H "Authorization: Bearer ${ACTION_TOKEN}" \
-              -H "Accept: application/octet-stream" \
-              "${GITHUB_API_URL}/repos/${ACTION_REPO}/releases/assets/${CHECKSUMS_ASSET_ID}" \
           -o "${{ runner.temp }}/checksums.txt"
-          else
-            curl -sSfL --connect-timeout 10 --max-time 120 \
-              -H "Accept: application/octet-stream" \
-              "${GITHUB_API_URL}/repos/${ACTION_REPO}/releases/assets/${BINARY_ASSET_ID}" \
-              -o "${{ runner.temp }}/review-bot"
-            curl -sSfL --connect-timeout 10 --max-time 30 \
-              -H "Accept: application/octet-stream" \
-              "${GITHUB_API_URL}/repos/${ACTION_REPO}/releases/assets/${CHECKSUMS_ASSET_ID}" \
-              -o "${{ runner.temp }}/checksums.txt"
-          fi
-        else
-          # Gitea: Direct download via web release URLs (Gitea serves assets
-          # directly without redirects — no -L needed).
-          # SECURITY: Omitting -L prevents forwarding Authorization header to
-          # unexpected hosts if Gitea ever introduces CDN redirects.
-          DOWNLOAD_URL="${SERVER_URL}/${ACTION_REPO}/releases/download/${VERSION}"
-
-          if [ -n "$ACTION_TOKEN" ]; then
-            curl -sSf --connect-timeout 10 --max-time 120 \
-              -H "Authorization: token ${ACTION_TOKEN}" \
-              "${DOWNLOAD_URL}/${BINARY}" -o "${{ runner.temp }}/review-bot"
-            curl -sSf --connect-timeout 10 --max-time 30 \
-              -H "Authorization: token ${ACTION_TOKEN}" \
-              "${DOWNLOAD_URL}/checksums.txt" -o "${{ runner.temp }}/checksums.txt"
-          else
-            curl -sSf --connect-timeout 10 --max-time 120 \
-              "${DOWNLOAD_URL}/${BINARY}" -o "${{ runner.temp }}/review-bot"
-            curl -sSf --connect-timeout 10 --max-time 30 \
-              "${DOWNLOAD_URL}/checksums.txt" -o "${{ runner.temp }}/checksums.txt"
-          fi
-        fi
 
         # Verify SHA-256 checksum
-        # NOTE: This verifies integrity (download wasn't corrupted) but not
-        # authenticity — both binary and checksums come from the same server.
-        # For stronger guarantees, consider GPG signature verification.
         cd "${{ runner.temp }}"
-        EXPECTED=$(grep -E "^[0-9a-f]+[[:space:]]+\*?${BINARY}$" checksums.txt | awk '{print $1}')
+        EXPECTED=$(grep "${BINARY}" checksums.txt | awk '{print $1}')
-        # sha256sum (GNU) is not available on macOS; use shasum -a 256 on darwin.
-        if [ "${OS}" = "darwin" ]; then
-          ACTUAL=$(shasum -a 256 review-bot | awk '{print $1}')
-        else
         ACTUAL=$(sha256sum review-bot | awk '{print $1}')
-        fi
 
         if [ -z "$EXPECTED" ]; then
           echo "Error: no checksum found for ${BINARY}" >&2
@@ -470,12 +164,12 @@ runs:
         fi
 
         chmod +x "${{ runner.temp }}/review-bot"
-        echo "Installed review-bot-${OS}-${ARCH} ${VERSION} (checksum verified)"
+        echo "Installed review-bot ${VERSION} (checksum verified)"
 
     - name: Run review
       shell: bash
       env:
-        VCS_URL: ${{ steps.version.outputs.server_url }}
+        GITEA_URL: ${{ inputs.gitea-url || github.server_url }}
         GITEA_REPO: ${{ inputs.repo || github.repository }}
         PR_NUMBER: ${{ inputs.pr-number || github.event.pull_request.number }}
         REVIEWER_TOKEN: ${{ inputs.reviewer-token }}

.gitea/workflows/ci.yml

@@ -49,7 +49,7 @@ jobs:
       - run: go build -o review-bot ./cmd/review-bot
       - name: Run ${{ matrix.name }} review
         env:
-          VCS_URL: ${{ github.server_url }}
+          GITEA_URL: ${{ github.server_url }}
           GITEA_REPO: ${{ github.repository }}
           PR_NUMBER: ${{ github.event.pull_request.number }}
           REVIEWER_TOKEN: ${{ secrets[matrix.token_secret] }}

.github/actions/review/action.yml

@@ -0,0 +1,200 @@
+# This composite action is designed for Gitea Actions runners.
+# Gitea Actions supports GitHub Actions syntax including $GITHUB_OUTPUT,
+# actions/cache, and actions/checkout.
+# Requirements: python3, sha256sum, curl (all present on ubuntu-* runners).
+name: 'AI Code Review'
+description: 'Run AI-powered code review on a pull request using review-bot'
+
+inputs:
+  gitea-url:
+    description: 'Gitea instance URL (defaults to server_url)'
+    required: false
+    default: ''
+  repo:
+    description: 'Repository (owner/name, defaults to current)'
+    required: false
+    default: ''
+  pr-number:
+    description: 'Pull request number (defaults to current PR)'
+    required: false
+    default: ''
+  reviewer-token:
+    description: 'Gitea token for posting the review'
+    required: true
+  reviewer-name:
+    description: 'Display name for the reviewer'
+    required: false
+    default: ''
+  llm-base-url:
+    description: 'OpenAI-compatible LLM API base URL (not required for aicore provider)'
+    required: false
+    default: ''
+  llm-api-key:
+    description: 'LLM API key (not required for aicore provider)'
+    required: false
+    default: ''
+  llm-model:
+    description: 'LLM model name'
+    required: true
+  llm-provider:
+    description: 'LLM API provider: openai, anthropic, or aicore (default openai)'
+    required: false
+    default: 'openai'
+  aicore-client-id:
+    description: 'SAP AI Core client ID (required for aicore provider)'
+    required: false
+    default: ''
+  aicore-client-secret:
+    description: 'SAP AI Core client secret (required for aicore provider)'
+    required: false
+    default: ''
+  aicore-auth-url:
+    description: 'SAP AI Core authentication URL (required for aicore provider)'
+    required: false
+    default: ''
+  aicore-api-url:
+    description: 'SAP AI Core API URL (required for aicore provider)'
+    required: false
+    default: ''
+  aicore-resource-group:
+    description: 'SAP AI Core resource group (default: default)'
+    required: false
+    default: 'default'
+  conventions-file:
+    description: 'Path to conventions file in the repo (e.g. CLAUDE.md)'
+    required: false
+    default: ''
+  patterns-repo:
+    description: 'Comma-separated repos with language patterns (e.g. rodin/elixir-patterns,rodin/phoenix-conventions)'
+    required: false
+    default: ''
+  patterns-files:
+    description: 'Comma-separated file paths or directories to fetch from patterns repos'
+    required: false
+    default: 'README.md'
+  temperature:
+    description: 'LLM temperature (0 = server default)'
+    required: false
+    default: '0'
+  timeout:
+    description: 'LLM request timeout in seconds (default 300)'
+    required: false
+    default: '300'
+  version:
+    description: 'review-bot version to install (e.g. v0.1.0, defaults to latest)'
+    required: false
+    default: 'latest'
+  dry-run:
+    description: 'Print review to stdout instead of posting'
+    required: false
+    default: 'false'
+  update-existing:
+    description: 'Delete previous review from same bot after posting new one. Accepts: true/1/yes or false/0/no (default true)'
+    required: false
+    default: 'true'
+  system-prompt-file:
+    description: 'Local file with additional system prompt instructions (e.g. security review focus)'
+    required: false
+    default: ''
+  persona:
+    description: 'Built-in persona name (security, architect, docs)'
+    required: false
+    default: ''
+  persona-file:
+    description: 'Path to custom persona JSON file'
+    required: false
+    default: ''
+
+runs:
+  using: 'composite'
+  steps:
+    - name: Determine version
+      id: version
+      shell: bash
+      run: |
+        GITEA_URL="${{ inputs.gitea-url || github.server_url }}"
+        REPO="${{ inputs.repo || 'rodin/review-bot' }}"
+        if [ "${{ inputs.version }}" = "latest" ]; then
+          VERSION=$(curl -sSf "${GITEA_URL}/api/v1/repos/${REPO}/releases?limit=1" \
+            | python3 -c "import sys, json; releases = json.load(sys.stdin); print(releases[0]['tag_name'] if releases else '')")
+          if [ -z "$VERSION" ]; then
+            echo "Failed to determine latest version" >&2
+            exit 1
+          fi
+        else
+          VERSION="${{ inputs.version }}"
+        fi
+        echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
+
+    - name: Cache review-bot binary
+      id: cache
+      uses: actions/cache@v4
+      with:
+        path: ${{ runner.temp }}/review-bot
+        key: review-bot-linux-amd64-${{ steps.version.outputs.version }}
+
+    - name: Install review-bot
+      if: steps.cache.outputs.cache-hit != 'true'
+      shell: bash
+      run: |
+        GITEA_URL="${{ inputs.gitea-url || github.server_url }}"
+        REPO="${{ inputs.repo || 'rodin/review-bot' }}"
+        VERSION="${{ steps.version.outputs.version }}"
+        BINARY="review-bot-linux-amd64"
+
+        curl -sSfL "${GITEA_URL}/${REPO}/releases/download/${VERSION}/${BINARY}" \
+          -o "${{ runner.temp }}/review-bot"
+        curl -sSfL "${GITEA_URL}/${REPO}/releases/download/${VERSION}/checksums.txt" \
+          -o "${{ runner.temp }}/checksums.txt"
+
+        # Verify SHA-256 checksum
+        cd "${{ runner.temp }}"
+        EXPECTED=$(grep "${BINARY}" checksums.txt | awk '{print $1}')
+        ACTUAL=$(sha256sum review-bot | awk '{print $1}')
+
+        if [ -z "$EXPECTED" ]; then
+          echo "Error: no checksum found for ${BINARY}" >&2
+          exit 1
+        fi
+        if [ "$EXPECTED" != "$ACTUAL" ]; then
+          echo "Error: checksum mismatch!" >&2
+          echo "  Expected: $EXPECTED" >&2
+          echo "  Actual:   $ACTUAL" >&2
+          exit 1
+        fi
+
+        chmod +x "${{ runner.temp }}/review-bot"
+        echo "Installed review-bot ${VERSION} (checksum verified)"
+
+    - name: Run review
+      shell: bash
+      env:
+        GITHUB_SERVER_URL: ${{ inputs.gitea-url || github.server_url }}
+        GITHUB_REPOSITORY: ${{ inputs.repo || github.repository }}
+        PR_NUMBER: ${{ inputs.pr-number || github.event.pull_request.number }}
+        REVIEWER_TOKEN: ${{ inputs.reviewer-token }}
+        REVIEWER_NAME: ${{ inputs.reviewer-name }}
+        LLM_BASE_URL: ${{ inputs.llm-base-url }}
+        LLM_API_KEY: ${{ inputs.llm-api-key }}
+        LLM_MODEL: ${{ inputs.llm-model }}
+        CONVENTIONS_FILE: ${{ inputs.conventions-file }}
+        PATTERNS_REPO: ${{ inputs.patterns-repo }}
+        PATTERNS_FILES: ${{ inputs.patterns-files }}
+        LLM_TEMPERATURE: ${{ inputs.temperature }}
+        LLM_TIMEOUT: ${{ inputs.timeout }}
+        LLM_PROVIDER: ${{ inputs.llm-provider }}
+        UPDATE_EXISTING: ${{ inputs.update-existing }}
+        SYSTEM_PROMPT_FILE: ${{ inputs.system-prompt-file }}
+        PERSONA: ${{ inputs.persona }}
+        PERSONA_FILE: ${{ inputs.persona-file }}
+        AICORE_CLIENT_ID: ${{ inputs.aicore-client-id }}
+        AICORE_CLIENT_SECRET: ${{ inputs.aicore-client-secret }}
+        AICORE_AUTH_URL: ${{ inputs.aicore-auth-url }}
+        AICORE_API_URL: ${{ inputs.aicore-api-url }}
+        AICORE_RESOURCE_GROUP: ${{ inputs.aicore-resource-group }}
+      run: |
+        ARGS=""
+        if [ "${{ inputs.dry-run }}" = "true" ]; then
+          ARGS="--dry-run"
+        fi
+        ${{ runner.temp }}/review-bot $ARGS

.github/workflows/ci.yml

@@ -0,0 +1,69 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    types: [opened, synchronize]
+
+jobs:
+  test:
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.26'
+      - run: go test ./...
+      - run: go vet ./...
+      - run: go build -o review-bot ./cmd/review-bot
+
+  # Self-review using native SAP AI Core provider
+  # Models must match SAP AI Core deployments
+  # Available models: gpt-5, anthropic--claude-4.6-sonnet, anthropic--claude-4.6-opus
+  # Removed gpt-4.1, gpt-5-mini, gpt-4.1-mini - not deployed on AI Core
+  review:
+    runs-on: ubuntu-24.04
+    if: github.event_name == 'pull_request'
+    needs: test
+    strategy:
+      matrix:
+        include:
+          - name: sonnet
+            token_secret: SONNET_REVIEW_TOKEN
+            model: anthropic--claude-4.6-sonnet
+          - name: gpt
+            token_secret: GPT_REVIEW_TOKEN
+            model: gpt-5
+          - name: security
+            token_secret: SECURITY_REVIEW_TOKEN
+            model: gpt-5
+            patterns_repo: rodin/security-patterns
+            patterns_files: "."
+            system_prompt_file: SECURITY_REVIEW.md
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.26'
+      - run: go build -o review-bot ./cmd/review-bot
+      - name: Run ${{ matrix.name }} review
+        env:
+          GITHUB_SERVER_URL: ${{ github.server_url }}
+          GITHUB_REPOSITORY: ${{ github.repository }}
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+          REVIEWER_TOKEN: ${{ secrets[matrix.token_secret] }}
+          REVIEWER_NAME: ${{ matrix.name }}
+          LLM_PROVIDER: aicore
+          LLM_MODEL: ${{ matrix.model }}
+          AICORE_CLIENT_ID: ${{ secrets.AICORE_CLIENT_ID }}
+          AICORE_CLIENT_SECRET: ${{ secrets.AICORE_CLIENT_SECRET }}
+          AICORE_AUTH_URL: ${{ secrets.AICORE_AUTH_URL }}
+          AICORE_API_URL: ${{ secrets.AICORE_API_URL }}
+          AICORE_RESOURCE_GROUP: ${{ secrets.AICORE_RESOURCE_GROUP }}
+          CONVENTIONS_FILE: "CONVENTIONS.md"
+          PATTERNS_REPO: ${{ matrix.patterns_repo || 'rodin/go-patterns' }}
+          PATTERNS_FILES: ${{ matrix.patterns_files || 'README.md,patterns/' }}
+          LLM_TIMEOUT: "600"
+          SYSTEM_PROMPT_FILE: ${{ matrix.system_prompt_file }}
+        run: ./review-bot

.github/workflows/pr-ready-gate.yml

@@ -0,0 +1,38 @@
+name: PR Ready Gate
+
+on:
+  pull_request:
+    types: [synchronize]
+
+jobs:
+  clear-labels:
+    runs-on: ubuntu-24.04
+    # Always run - curl commands are safe if labels don't exist
+    steps:
+      - name: Remove ready and self-reviewed labels, reassign to author
+        env:
+          GITEA_TOKEN: ${{ secrets.RODIN_TOKEN }}
+        run: |
+          PR_NUMBER=${{ github.event.pull_request.number }}
+          AUTHOR=${{ github.event.pull_request.user.login }}
+          READY_LABEL_ID=38
+          SELF_REVIEWED_LABEL_ID=37
+          
+          # Remove ready label if present
+          curl -sS -X DELETE \
+            -H "Authorization: token $GITEA_TOKEN" \
+            "https://gitea.weiker.me/api/v1/repos/${{ github.repository }}/issues/${PR_NUMBER}/labels/${READY_LABEL_ID}" || true
+          
+          # Remove self-reviewed label if present
+          curl -sS -X DELETE \
+            -H "Authorization: token $GITEA_TOKEN" \
+            "https://gitea.weiker.me/api/v1/repos/${{ github.repository }}/issues/${PR_NUMBER}/labels/${SELF_REVIEWED_LABEL_ID}" || true
+          
+          # Reassign to author
+          curl -sS -X PATCH \
+            -H "Authorization: token $GITEA_TOKEN" \
+            -H "Content-Type: application/json" \
+            -d "{\"assignees\": [\"${AUTHOR}\"]}" \
+            "https://gitea.weiker.me/api/v1/repos/${{ github.repository }}/pulls/${PR_NUMBER}"
+          
+          echo "Cleared ready/self-reviewed labels and reassigned PR #${PR_NUMBER} to ${AUTHOR}"

.github/workflows/release.yml

@@ -0,0 +1,97 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  release:
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.26'
+
+      - name: Run tests
+        run: |
+          go vet ./...
+          go test ./...
+
+      - name: Build binaries
+        run: |
+          VERSION=${GITHUB_REF_NAME}
+          mkdir -p dist
+
+          GOOS=linux GOARCH=amd64 go build -ldflags "-s -w -X main.version=${VERSION}" -o dist/review-bot-linux-amd64 ./cmd/review-bot
+          GOOS=linux GOARCH=arm64 go build -ldflags "-s -w -X main.version=${VERSION}" -o dist/review-bot-linux-arm64 ./cmd/review-bot
+          GOOS=darwin GOARCH=amd64 go build -ldflags "-s -w -X main.version=${VERSION}" -o dist/review-bot-darwin-amd64 ./cmd/review-bot
+          GOOS=darwin GOARCH=arm64 go build -ldflags "-s -w -X main.version=${VERSION}" -o dist/review-bot-darwin-arm64 ./cmd/review-bot
+
+          cd dist && sha256sum * > checksums.txt
+
+      - name: Create release and upload assets
+        env:
+          GITEA_TOKEN: ${{ secrets.RELEASE_TOKEN }}
+        run: |
+          VERSION=${GITHUB_REF_NAME}
+          GITEA_URL="${{ github.server_url }}"
+          REPO="${{ github.repository }}"
+
+          # Create release (or find existing one for this tag)
+          HTTP_CODE=$(curl -s -o /tmp/release_response.json -w "%{http_code}" -X POST \
+            -H "Authorization: token ${GITEA_TOKEN}" \
+            -H "Content-Type: application/json" \
+            "${GITEA_URL}/api/v1/repos/${REPO}/releases" \
+            -d "{\"tag_name\": \"${VERSION}\", \"name\": \"${VERSION}\", \"body\": \"Release ${VERSION}\", \"draft\": false, \"prerelease\": false}")
+
+          if [ "$HTTP_CODE" = "409" ]; then
+            echo "Release for ${VERSION} already exists, fetching existing..."
+            curl -sSf -o /tmp/release_response.json \
+              -H "Authorization: token ${GITEA_TOKEN}" \
+              "${GITEA_URL}/api/v1/repos/${REPO}/releases/tags/${VERSION}"
+          elif [ "$HTTP_CODE" != "201" ]; then
+            echo "Failed to create release (HTTP ${HTTP_CODE})" >&2
+            cat /tmp/release_response.json >&2
+            exit 1
+          fi
+
+          # Parse release ID (python3 available on ubuntu-24.04 runners)
+          RELEASE_ID=$(python3 -c "import json; print(json.load(open('/tmp/release_response.json'))['id'])")
+
+          if [ -z "$RELEASE_ID" ]; then
+            echo "Failed to parse release ID" >&2
+            cat /tmp/release_response.json >&2
+            exit 1
+          fi
+
+          echo "Release ID: ${RELEASE_ID}"
+
+          # Upload each asset (idempotent: delete existing asset with same name first)
+          for file in dist/*; do
+            filename=$(basename "$file")
+            echo "Uploading ${filename}..."
+
+            # Check if asset already exists and delete it
+            EXISTING_ID=$(export ASSET_NAME="${filename}"; curl -sS \
+              -H "Authorization: token ${GITEA_TOKEN}" \
+              "${GITEA_URL}/api/v1/repos/${REPO}/releases/${RELEASE_ID}/assets" \
+              | python3 -c "import json,sys,os; name=os.environ['ASSET_NAME']; assets=json.load(sys.stdin); print(next((str(a['id']) for a in assets if a['name']==name),''))" 2>/dev/null)
+
+            if [ -n "$EXISTING_ID" ]; then
+              echo "  Asset ${filename} already exists (id=${EXISTING_ID}), deleting..."
+              curl -sSf -X DELETE \
+                -H "Authorization: token ${GITEA_TOKEN}" \
+                "${GITEA_URL}/api/v1/repos/${REPO}/releases/${RELEASE_ID}/assets/${EXISTING_ID}"
+            fi
+
+            curl -sSf -X POST \
+              -H "Authorization: token ${GITEA_TOKEN}" \
+              -H "Content-Type: application/octet-stream" \
+              "${GITEA_URL}/api/v1/repos/${REPO}/releases/${RELEASE_ID}/assets?name=$(printf '%s' "${filename}" | jq -sRr @uri)" \
+              --data-binary "@${file}"
+          done
+
+          echo "Release ${VERSION} created with assets"

CONVENTIONS.md

@@ -9,7 +9,7 @@
 
 | Package | Use Case | Scope |
 |---------|----------|-------|
-| `github.com/goccy/go-yaml` | YAML parsing and AST inspection (subpkgs: `ast`, `parser`) | production |
+| `gopkg.in/yaml.v3` | YAML parsing (persona files, config) | production |
 | `github.com/google/go-cmp` | Test comparisons (`cmp.Diff`) | test only |
 
 **Any import not in this table or the Go standard library is forbidden.**

PLAN-125.md

@@ -1,175 +0,0 @@
-# Plan: Issue #125 — Rename GITEA_URL → VCS_URL
-
-## Problem
-
-The `GITEA_URL` environment variable (and `--gitea-url` flag) implies the binary only works with Gitea.
-Now that review-bot supports both Gitea and GitHub/GHES, this name is misleading.
-Renaming to `VCS_URL` makes the binary platform-agnostic in its interface.
-
-## Constraints
-
-- Must not break existing users who already use `GITEA_URL` — need a fallback
-- The CLI flag `--gitea-url` should also be updated to `--vcs-url` for consistency
-- `INTEGRATION_GITEA_URL` in integration tests is a test-only env var, not the binary's interface; but should be updated for clarity
-- The action YAML uses `GITEA_URL` as an internal shell variable in bash scripts — distinct from the env var passed to the binary
-- All changes must compile and pass existing tests
-
-## Files Affected
-
-### Binary / Go source
-| File | Change |
-|------|--------|
-| `cmd/review-bot/main.go` | Rename `--gitea-url` → `--vcs-url`, add `VCS_URL` as primary, keep `GITEA_URL` fallback |
-| `cmd/review-bot/integration_test.go` | Rename `INTEGRATION_GITEA_URL` → `INTEGRATION_VCS_URL` (test-only, no external compat concern) |
-| `integration_test.go` | Same — rename `INTEGRATION_GITEA_URL` → `INTEGRATION_VCS_URL` |
-
-### Action YAML
-| File | Change |
-|------|--------|
-| `.gitea/actions/review/action.yml` | Rename input `gitea-url` → `vcs-url`; update env var passed to binary: `VCS_URL` instead of `GITEA_URL`; keep internal bash var as `GITEA_URL` (only used for release download, not passed to binary) |
-| `.gitea/workflows/ci.yml` | Rename `GITEA_URL` env var to `VCS_URL` in Run review step |
-
-### Documentation
-| File | Change |
-|------|--------|
-| `README.md` | Update CLI example, env var table entry |
-
-## Proposed Approach
-
-### 1. Backward-compatible env var lookup in main.go
-
-Replace:
-```go
-giteaURL := flag.String("gitea-url", envOrDefault("GITEA_URL", ""), "Gitea instance URL")
-```
-
-With:
-```go
-giteaURL := flag.String("vcs-url", envOrDefaultFallback("VCS_URL", "GITEA_URL", ""), "VCS server URL (e.g. https://gitea.example.com)")
-```
-
-Add a helper:
-```go
-// envOrDefaultFallback reads primary env var; if empty, falls back to deprecated env var.
-func envOrDefaultFallback(primary, deprecated, defaultVal string) string {
-    if v := os.Getenv(primary); v != "" {
-        return v
-    }
-    if v := os.Getenv(deprecated); v != "" {
-        slog.Warn("deprecated env var in use; rename to " + primary, "old", deprecated, "new", primary)
-        return v
-    }
-    return defaultVal
-}
-```
-
-**Note:** This must be called AFTER `setupLogger` conceptually, but the flag default is evaluated at flag registration time. Since `setupLogger` runs before `flag.Parse()`, the slog.Warn will print correctly at runtime. We use `log.Printf` as a fallback if this proves problematic.
-
-Actually — flag defaults are evaluated at registration (line 57), before `setupLogger`. The warning won't go through slog. Two options:
-- Use `log.Printf` for the deprecation warning (always visible)
-- Move the fallback lookup to after `flag.Parse()`, checking if the parsed value is still empty
-
-**Decision:** Move fallback to a post-parse check. This is cleaner:
-```go
-vcsURL := flag.String("vcs-url", os.Getenv("VCS_URL"), "VCS server URL")
-flag.Parse()
-// Backward compat: fall back to deprecated GITEA_URL
-if *vcsURL == "" {
-    if v := os.Getenv("GITEA_URL"); v != "" {
-        slog.Warn("GITEA_URL is deprecated; use VCS_URL instead")
-        *vcsURL = v
-    }
-}
-```
-
-This is clean, idiomatic, and the warning goes through slog correctly.
-
-### 2. Keep `--gitea-url` as deprecated alias
-
-Add a hidden flag for backward compat:
-```go
-giteaURLAlias := flag.String("gitea-url", "", "Deprecated: use --vcs-url")
-```
-
-Post-parse:
-```go
-if *vcsURL == "" && *giteaURLAlias != "" {
-    slog.Warn("--gitea-url is deprecated; use --vcs-url instead")
-    *vcsURL = *giteaURLAlias
-}
-```
-
-### 3. Internal variable rename
-
-Rename `giteaURL` local variable → `vcsURL` throughout `main.go` for consistency.
-
-### 4. Error message update
-
-```go
-fmt.Fprintf(os.Stderr, "Required: --vcs-url, --repo, --pr, --reviewer-token, --llm-model\n")
-```
-
-### 5. Action YAML changes
-
-In `.gitea/actions/review/action.yml`:
-- Input `gitea-url` → `vcs-url` (with same description, `required: false`, `default: ''`)
-- Line 172: `GITEA_URL: ${{ inputs.gitea-url || github.server_url }}` → `VCS_URL: ${{ inputs.vcs-url || github.server_url }}`
-- Lines 115, 140: internal bash vars `GITEA_URL=` are used for downloading binaries — NOT passed to the review-bot binary. Leave them as internal bash vars (they're scope-local in bash). These could be renamed to `SERVER_URL` or `BASE_URL` for local clarity, but renaming them isn't strictly required.
-
-In `.gitea/workflows/ci.yml`:
-- Line 52: `GITEA_URL: ${{ github.server_url }}` → `VCS_URL: ${{ github.server_url }}`
-
-### 6. Integration test updates
-
-`INTEGRATION_GITEA_URL` → `INTEGRATION_VCS_URL` in both test files.
-
-### 7. README
-
-- CLI example: `--gitea-url` → `--vcs-url`
-- Env var table: `GITEA_URL` → `VCS_URL`, add note about `GITEA_URL` fallback
-
-## Backward Compatibility Summary
-
-| Old | New | Fallback? |
-|-----|-----|-----------|
-| `GITEA_URL` env var | `VCS_URL` | ✅ with deprecation warning |
-| `--gitea-url` flag | `--vcs-url` | ✅ with deprecation warning |
-| `gitea-url` action input | `vcs-url` | ⚠️ No (action version bump handles this) |
-| `INTEGRATION_GITEA_URL` | `INTEGRATION_VCS_URL` | N/A (test-only) |
-
-## Error Cases
-
-- Both `VCS_URL` and `GITEA_URL` set: `VCS_URL` wins (primary takes precedence)
-- Both `--vcs-url` and `--gitea-url` provided: `--vcs-url` wins
-- Neither set: existing "missing required flags" error unchanged
-
-## Edge Cases
-
-- `os.Getenv` returns "" for unset AND set-to-empty — consistent with existing behavior
-- The `envOrDefault` helper is unchanged; we add `envOrDefaultFallback` for the one renamed var
-
-## Testing Strategy
-
-- Existing unit tests pass unchanged (they don't test env var parsing directly)
-- Integration tests updated to use new env var name
-- Manual: `GITEA_URL=https://example.com ./review-bot --repo x --pr 1 ...` should print deprecation warning and proceed
-- Manual: `VCS_URL=https://example.com ./review-bot ...` should work silently
-
-## Completion Checklist
-
-1. `VCS_URL` is read first; `GITEA_URL` is fallback with deprecation warning
-2. `--vcs-url` flag is primary; `--gitea-url` is deprecated alias with warning
-3. Error message references `--vcs-url` not `--gitea-url`
-4. `action.yml` passes `VCS_URL` (not `GITEA_URL`) to the binary
-5. `ci.yml` passes `VCS_URL` (not `GITEA_URL`) to the binary
-6. README updated in CLI example and env var table
-7. Integration tests use `INTEGRATION_VCS_URL`
-8. `go test ./...` passes
-9. `go vet ./...` passes
-10. `go build ./cmd/review-bot` succeeds
-
-## Open Questions
-
-- Should the CLI flag `--gitea-url` be completely hidden from `--help` or just deprecated with a note? The issue doesn't specify. Decision: keep it visible but add "(deprecated: use --vcs-url)" to the description.
-- Should action.yml also add `gitea-url` as a deprecated input alias? The issue says "Update the action to pass the new env var name" — no mention of backward compat for the action input. Decision: rename only, no alias (action users pin a version anyway).
-- The bash-internal `GITEA_URL` variable in action.yml scripts (used for release download, not passed to binary) — rename for clarity? Decision: yes, rename to `BASE_URL` to avoid confusion with the env var.

README.md

@@ -282,7 +282,7 @@ Rules:
 
 ```bash
 review-bot \
-  --vcs-url https://gitea.example.com \
+  --gitea-url https://gitea.example.com \
   --repo owner/name \
   --pr 42 \
   --reviewer-token "$GITEA_TOKEN" \
@@ -299,7 +299,7 @@ All flags have environment variable equivalents:
 
 | Flag | Env Var |
 |------|---------|
-| `--vcs-url` | `VCS_URL` (fallback: `GITEA_URL`) |
+| `--gitea-url` | `GITEA_URL` |
 | `--repo` | `GITEA_REPO` |
 | `--pr` | `PR_NUMBER` |
 | `--reviewer-token` | `REVIEWER_TOKEN` |

TODO.md

@@ -1,42 +0,0 @@
-## Dev Loop: review-bot — 2026-05-14 19:15 UTC
-
-### Latest: ✅ issue-123 MERGED
-- **PR #129:** Merged to main at commit 4440823
-- **Feature:** IP-level SSRF defense with RFC6598 CGN check
-- **Status:** Complete, all review feedback addressed
-
----
-
-## Review-Bot Current State
-
-### Merged to main:
-- ✅ issue-123 (SSRF defense) — 5 commits
-- ✅ issue-125 (VCS_URL rename + deprecation) 
-- ✅ issue-124 (multi-arch binary support)
-- ✅ issue-120 (GitHub Actions + VCS abstraction) — partial merge
-- And 100+ prior completed issues
-
-### Open Branches (>0 commits ahead of main):
-- **issue-120:** 30 commits ahead (GHE release dry-run + extensive VCS abstraction work)
-  - Status: Awaiting human review/decision on integration
-
-### Completed Recently:
-- Multiple issue-* and review-bot-issue-* branches
-- All recent work landed in main or merged into feature branches
-
----
-
-## Next Actions for Dev-Loop
-
-1. **Check if issue-120 needs human intervention or PR created**
-2. **Identify next highest-priority open issue to start**
-3. **Review any blocked or stalled branches**
-4. **Perform health check:**
-   - No orphaned worktrees
-   - No merge conflicts
-   - All tests passing on main
-
----
-
-## Worktrees Active
- worktrees active

cmd/review-bot/integration_test.go

@@ -17,7 +17,7 @@ import (
 // Integration test requires a running Gitea instance and LLM endpoint.
 // Set environment variables:
 //
-//	INTEGRATION_VCS_URL       - VCS base URL
+//	INTEGRATION_GITEA_URL     - Gitea base URL
 //	INTEGRATION_GITEA_TOKEN   - Gitea API token with repo access
 //	INTEGRATION_GITEA_REPO    - owner/repo with an open PR
 //	INTEGRATION_PR_NUMBER     - PR number to test against
@@ -25,7 +25,7 @@ import (
 //	INTEGRATION_LLM_API_KEY   - LLM API key
 //	INTEGRATION_LLM_MODEL     - Model name
 func TestIntegration_FullReviewFlow(t *testing.T) {
-	giteaURL := os.Getenv("INTEGRATION_VCS_URL")
+	giteaURL := os.Getenv("INTEGRATION_GITEA_URL")
 	giteaToken := os.Getenv("INTEGRATION_GITEA_TOKEN")
 	giteaRepo := os.Getenv("INTEGRATION_GITEA_REPO")
 	prNumStr := os.Getenv("INTEGRATION_PR_NUMBER")
@@ -104,7 +104,7 @@ func TestIntegration_FullReviewFlow(t *testing.T) {
 }
 
 func TestIntegration_PostAndCleanup(t *testing.T) {
-	giteaURL := os.Getenv("INTEGRATION_VCS_URL")
+	giteaURL := os.Getenv("INTEGRATION_GITEA_URL")
 	giteaToken := os.Getenv("INTEGRATION_GITEA_TOKEN")
 	giteaRepo := os.Getenv("INTEGRATION_GITEA_REPO")
 	prNumStr := os.Getenv("INTEGRATION_PR_NUMBER")
@@ -130,7 +130,7 @@ func TestIntegration_PostAndCleanup(t *testing.T) {
 	// Post a test review
 	sentinel := "<!-- review-bot:integration-test -->"
 	testBody := "# Integration Test Review\n\nThis is a test review.\n\n" + sentinel
-	posted, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, "COMMENT", testBody, "", nil)
+	posted, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, "COMMENT", testBody, nil)
 	if err != nil {
 		t.Fatalf("PostReview: %v", err)
 	}

cmd/review-bot/main.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"io"
 	"log/slog"
 	"os"
 	"path/filepath"
@@ -16,17 +15,11 @@ import (
 	"gitea.weiker.me/rodin/review-bot/gitea"
 	"gitea.weiker.me/rodin/review-bot/llm"
 	"gitea.weiker.me/rodin/review-bot/review"
+	"gitea.weiker.me/rodin/review-bot/vcs"
 )
 
 var version = "dev"
 
-// outWriter and errWriter are the output and error writers for subcommands.
-// They are variables so tests can capture output.
-var (
-	outWriter io.Writer = os.Stdout
-	errWriter io.Writer = os.Stderr
-)
-
 // setupLogger configures the global slog default logger based on format and verbosity.
 func setupLogger(format, verbosity string) {
 	var level slog.Level
@@ -57,23 +50,13 @@ func setupLogger(format, verbosity string) {
 }
 
 func main() {
-	// Dispatch subcommands before flag parsing so they get their own args.
-	// e.g. `review-bot validate-url <url>`
-	if len(os.Args) > 1 {
-		switch os.Args[1] {
-		case "validate-url":
-			os.Exit(runValidateURL(os.Args[2:]))
-		}
-	}
-
 	versionFlag := flag.Bool("version", false, "Print version and exit")
 	// Logging flags
 	logFormat := flag.String("log-format", envOrDefault("LOG_FORMAT", "text"), "Log output format: text or json")
 	verbosity := flag.String("verbosity", envOrDefault("LOG_VERBOSITY", "info"), "Log verbosity: debug, info, warn, error")
 	// CLI flags
-	vcsURL := flag.String("vcs-url", os.Getenv("VCS_URL"), "VCS server URL (e.g. https://gitea.example.com)")
+	giteaURL := flag.String("gitea-url", envOrDefault("GITEA_URL", envOrDefault("GITHUB_SERVER_URL", "")), "Gitea instance URL")
-	giteaURLAlias := flag.String("gitea-url", "", "Deprecated: use --vcs-url")
+	repo := flag.String("repo", envOrDefault("GITEA_REPO", envOrDefault("GITHUB_REPOSITORY", "")), "Repository (owner/name)")
-	repo := flag.String("repo", envOrDefault("GITEA_REPO", ""), "Repository (owner/name)")
 	prNum := flag.String("pr", envOrDefault("PR_NUMBER", ""), "Pull request number")
 	reviewerName := flag.String("reviewer-name", envOrDefault("REVIEWER_NAME", ""), "Reviewer display name")
 	reviewerToken := flag.String("reviewer-token", envOrDefault("REVIEWER_TOKEN", ""), "Gitea token for posting review")
@@ -83,7 +66,7 @@ func main() {
 	conventionsFile := flag.String("conventions-file", envOrDefault("CONVENTIONS_FILE", ""), "Conventions file path in repo (e.g. CLAUDE.md)")
 	systemPromptFile := flag.String("system-prompt-file", envOrDefault("SYSTEM_PROMPT_FILE", ""), "Local file with additional system prompt instructions")
 	patternsRepo := flag.String("patterns-repo", envOrDefault("PATTERNS_REPO", ""), "Repo with language patterns (e.g. rodin/elixir-patterns)")
-	patternsFiles := flag.String("patterns-files", envOrDefault("PATTERNS_FILES", ""), "Comma-separated file paths to fetch from patterns repo (empty = all files)")
+	patternsFiles := flag.String("patterns-files", envOrDefault("PATTERNS_FILES", "README.md"), "Comma-separated file paths to fetch from patterns repo")
 	dryRun := flag.Bool("dry-run", false, "Print review to stdout instead of posting")
 	llmTemp := flag.Float64("llm-temperature", envOrDefaultFloat("LLM_TEMPERATURE", 0), "LLM temperature (0 = server default)")
 	llmTimeout := flag.Int("llm-timeout", envOrDefaultInt("LLM_TIMEOUT", 300), "LLM request timeout in seconds (default 300)")
@@ -109,24 +92,12 @@ func main() {
 
 	slog.Info("review-bot starting", "version", version)
 
-	// Backward compatibility: fall back to deprecated env var / flag if VCS_URL / --vcs-url not set.
-	if *vcsURL == "" {
-		if v := os.Getenv("GITEA_URL"); v != "" {
-			slog.Warn("GITEA_URL is deprecated; rename the environment variable to VCS_URL")
-			*vcsURL = v
-		}
-	}
-	if *vcsURL == "" && *giteaURLAlias != "" {
-		slog.Warn("--gitea-url is deprecated; use --vcs-url instead")
-		*vcsURL = *giteaURLAlias
-	}
-
 	// Validate required fields
 	// For aicore provider, llm-base-url and llm-api-key are not required
 	isAICore := llm.Provider(*llmProvider) == llm.ProviderAICore
-	if *vcsURL == "" || *repo == "" || *prNum == "" || *reviewerToken == "" || *llmModel == "" {
+	if *giteaURL == "" || *repo == "" || *prNum == "" || *reviewerToken == "" || *llmModel == "" {
 		fmt.Fprintf(os.Stderr, "Error: missing required flags or environment variables\n\n")
-		fmt.Fprintf(os.Stderr, "Required: --vcs-url, --repo, --pr, --reviewer-token, --llm-model\n")
+		fmt.Fprintf(os.Stderr, "Required: --gitea-url, --repo, --pr, --reviewer-token, --llm-model\n")
 		os.Exit(1)
 	}
 	if !isAICore && (*llmBaseURL == "" || *llmAPIKey == "") {
@@ -169,7 +140,7 @@ func main() {
 	}
 
 	// Initialize clients
-	giteaClient := gitea.NewClient(*vcsURL, *reviewerToken)
+	giteaClient := gitea.NewClient(*giteaURL, *reviewerToken)
 	llmClient := llm.NewClient(*llmBaseURL, *llmAPIKey, *llmModel)
 	if *llmTemp < 0 || *llmTemp > 2 {
 		slog.Error("invalid LLM temperature", "temperature", *llmTemp, "range", "0-2")
@@ -474,7 +445,7 @@ func main() {
 
 	// POST new review
 	slog.Info("posting review", "event", event, "pr", prNumber)
-	posted, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, event, reviewBody, evaluatedSHA, inlineComments)
+	posted, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, event, reviewBody, inlineComments)
 	if err != nil {
 		slog.Error("failed to post review", "pr", prNumber, "event", event, "error", err)
 		os.Exit(1)
@@ -483,7 +454,7 @@ func main() {
 
 	// Supersede all old reviews with link to the new one
 	if len(oldReviews) > 0 {
-		newReviewURL := fmt.Sprintf("%s/%s/%s/pulls/%d#pullrequestreview-%d", strings.TrimRight(*vcsURL, "/"), owner, repoName, prNumber, posted.ID)
+		newReviewURL := fmt.Sprintf("%s/%s/%s/pulls/%d#pullrequestreview-%d", strings.TrimRight(*giteaURL, "/"), owner, repoName, prNumber, posted.ID)
 		for _, oldReview := range oldReviews {
 			cid, err := giteaClient.GetTimelineReviewCommentIDForReview(ctx, owner, repoName, prNumber, oldReview.ID)
 			if err != nil {
@@ -553,25 +524,11 @@ func fetchFileContext(ctx context.Context, client *gitea.Client, owner, repo, re
 // patternsRepo is comma-separated list of owner/name repos.
 // patternsFiles is comma-separated list of file paths or directories.
 // If a path ends with / or is a directory, all files within it are fetched recursively.
-// If patternsFiles is empty, all files from the repo root are fetched.
 func fetchPatterns(ctx context.Context, client *gitea.Client, patternsRepo, patternsFiles string) string {
 	var sb strings.Builder
 
 	repos := strings.Split(patternsRepo, ",")
-
+	paths := strings.Split(patternsFiles, ",")
-	// Build the list of paths to fetch
-	var paths []string
-	if patternsFiles == "" {
-		// Empty patternsFiles means "fetch all files from repo root"
-		paths = []string{""}
-	} else {
-		for _, p := range strings.Split(patternsFiles, ",") {
-			p = strings.TrimSpace(p)
-			if p != "" {
-				paths = append(paths, p)
-			}
-		}
-	}
 
 	for _, repoRef := range repos {
 		if ctx.Err() != nil {
@@ -592,6 +549,11 @@ func fetchPatterns(ctx context.Context, client *gitea.Client, patternsRepo, patt
 		var repoSkippedFiles []string
 
 		for _, path := range paths {
+			path = strings.TrimSpace(path)
+			if path == "" {
+				continue
+			}
+
 			files, err := client.GetAllFilesInPath(ctx, owner, repo, path)
 			if err != nil {
 				slog.Warn("could not fetch patterns", "path", path, "repo", repoRef, "error", err)
@@ -851,7 +813,7 @@ func shouldSkipStaleReview(evaluatedSHA, currentSHA string) bool {
 	return evaluatedSHA != currentSHA
 }
 
-// giteaClientAdapter adapts gitea.Client to review.GiteaClient interface.
+// giteaClientAdapter adapts gitea.Client to vcs.FileReader interface.
 type giteaClientAdapter struct {
 	client *gitea.Client
 }
@@ -860,14 +822,14 @@ func newGiteaClientAdapter(c *gitea.Client) *giteaClientAdapter {
 	return &giteaClientAdapter{client: c}
 }
 
-func (a *giteaClientAdapter) ListContents(ctx context.Context, owner, repo, path string) ([]review.ContentEntry, error) {
+func (a *giteaClientAdapter) ListContents(ctx context.Context, owner, repo, path string) ([]vcs.ContentEntry, error) {
 	entries, err := a.client.ListContents(ctx, owner, repo, path)
 	if err != nil {
 		return nil, err
 	}
-	result := make([]review.ContentEntry, len(entries))
+	result := make([]vcs.ContentEntry, len(entries))
 	for i, e := range entries {
-		result[i] = review.ContentEntry{
+		result[i] = vcs.ContentEntry{
 			Name: e.Name,
 			Path: e.Path,
 			Type: e.Type,
@@ -876,6 +838,9 @@ func (a *giteaClientAdapter) ListContents(ctx context.Context, owner, repo, path
 	return result, nil
 }
 
-func (a *giteaClientAdapter) GetFileContent(ctx context.Context, owner, repo, filepath string) (string, error) {
+func (a *giteaClientAdapter) GetFileContent(ctx context.Context, owner, repo, filePath, ref string) (string, error) {
-	return a.client.GetFileContent(ctx, owner, repo, filepath)
+	if ref != "" {
+		return a.client.GetFileContentRef(ctx, owner, repo, filePath, ref)
+	}
+	return a.client.GetFileContent(ctx, owner, repo, filePath)
 }

cmd/review-bot/main_test.go

@@ -504,52 +504,6 @@ func TestIsPatternFile(t *testing.T) {
 	}
 }
 
-// TestBuildPatternPaths verifies the path-building logic for fetchPatterns.
-// Empty patternsFiles means "fetch all from root" (represented as [""]).
-func TestBuildPatternPaths(t *testing.T) {
-	buildPaths := func(patternsFiles string) []string {
-		if patternsFiles == "" {
-			return []string{""}
-		}
-		var paths []string
-		for _, p := range strings.Split(patternsFiles, ",") {
-			p = strings.TrimSpace(p)
-			if p != "" {
-				paths = append(paths, p)
-			}
-		}
-		return paths
-	}
-
-	tests := []struct {
-		name  string
-		input string
-		want  []string
-	}{
-		{"empty fetches root", "", []string{""}},
-		{"single file", "README.md", []string{"README.md"}},
-		{"multiple files", "README.md,PATTERNS.md", []string{"README.md", "PATTERNS.md"}},
-		{"trims whitespace", " foo.md , bar.md ", []string{"foo.md", "bar.md"}},
-		{"skips empty between commas", "foo.md,,bar.md", []string{"foo.md", "bar.md"}},
-		{"directory path", "patterns/", []string{"patterns/"}},
-	}
-
-	for _, tc := range tests {
-		t.Run(tc.name, func(t *testing.T) {
-			got := buildPaths(tc.input)
-			if len(got) != len(tc.want) {
-				t.Errorf("buildPaths(%q) = %v, want %v", tc.input, got, tc.want)
-				return
-			}
-			for i := range got {
-				if got[i] != tc.want[i] {
-					t.Errorf("buildPaths(%q)[%d] = %q, want %q", tc.input, i, got[i], tc.want[i])
-				}
-			}
-		})
-	}
-}
-
 func TestEvaluateCIStatus(t *testing.T) {
 	tests := []struct {
 		name       string

cmd/review-bot/validateurl.go

@@ -1,125 +0,0 @@
-package main
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"net"
-	"net/url"
-	"strings"
-	"time"
-
-	"gitea.weiker.me/rodin/review-bot/gitea"
-)
-
-// runValidateURL implements the `review-bot validate-url <url>` subcommand.
-//
-// It resolves the given URL's hostname and checks that every returned IP is
-// publicly routable (not RFC1918, loopback, link-local, or other reserved
-// ranges). The exit code communicates the result to callers:
-//
-//	0 — URL is safe to use
-//	1 — URL resolves to a blocked/private address
-//	2 — URL is malformed, has an unsafe scheme, or DNS lookup failed
-//
-// This is intended for use from action.yml shell steps that need to validate
-// a user-supplied URL before passing it to curl.
-func runValidateURL(args []string) int {
-	if len(args) != 1 {
-		fmt.Fprintln(errWriter, "usage: review-bot validate-url <url>")
-		fmt.Fprintln(errWriter, "")
-		fmt.Fprintln(errWriter, "Resolves <url> and verifies all resolved IPs are publicly routable.")
-		fmt.Fprintln(errWriter, "Exit 0=safe, 1=blocked, 2=error")
-		return 2
-	}
-	rawURL := args[0]
-
-	if err := validateURL(rawURL); err != nil {
-		fmt.Fprintf(errWriter, "Error: %v\n", err)
-		var ve *validateError
-		if isValidateError(err, &ve) {
-			return ve.code
-		}
-		return 2
-	}
-	fmt.Fprintf(outWriter, "OK: %s is safe\n", rawURL)
-	return 0
-}
-
-// validateError carries an exit code alongside a message.
-type validateError struct {
-	code    int
-	message string
-}
-
-func (e *validateError) Error() string { return e.message }
-
-// isValidateError checks if err is or wraps a *validateError and sets out.
-// Uses errors.As so that wrapped *validateError values (e.g. from fmt.Errorf("...: %w", &validateError{...}))
-// are also detected, making the function robust against future wrapping.
-func isValidateError(err error, out **validateError) bool {
-	if err == nil {
-		return false
-	}
-	return errors.As(err, out)
-}
-
-// validateURL checks that rawURL is safe for use as a Gitea server URL:
-//   - Must be https:// (not http://)
-//   - Must have no user-info (user:pass@host)
-//   - Must resolve to at least one IP, all of which are publicly routable
-func validateURL(rawURL string) error {
-	parsed, err := url.Parse(rawURL)
-	if err != nil {
-		return &validateError{code: 2, message: fmt.Sprintf("malformed URL %q: %v", rawURL, err)}
-	}
-
-	// Scheme check: only https is permitted.
-	if !strings.EqualFold(parsed.Scheme, "https") {
-		return &validateError{
-			code:    2,
-			message: fmt.Sprintf("URL scheme must be https (got %q)", parsed.Scheme),
-		}
-	}
-
-	// Reject user-info (user:password@host) to prevent credential embedding.
-	if parsed.User != nil {
-		return &validateError{
-			code:    2,
-			message: "URL must not contain user-info (user:password@host)",
-		}
-	}
-
-	host := parsed.Hostname()
-	if host == "" {
-		return &validateError{code: 2, message: fmt.Sprintf("URL has no host: %q", rawURL)}
-	}
-
-	// Resolve the hostname with a short timeout.
-	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-	defer cancel()
-
-	addrs, err := net.DefaultResolver.LookupIPAddr(ctx, host)
-	if err != nil {
-		return &validateError{
-			code:    2,
-			message: fmt.Sprintf("DNS lookup failed for %q: %v", host, err),
-		}
-	}
-	if len(addrs) == 0 {
-		return &validateError{
-			code:    2,
-			message: fmt.Sprintf("DNS lookup returned no addresses for %q", host),
-		}
-	}
-
-	for _, a := range addrs {
-		if gitea.IsBlockedIP(a.IP) {
-			return &validateError{
-				code:    1,
-				message: fmt.Sprintf("blocked: %q resolves to private/reserved IP %s", host, a.IP),
-			}
-		}
-	}
-	return nil
-}

cmd/review-bot/validateurl_test.go

@@ -1,127 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"strings"
-	"testing"
-)
-
-func TestRunValidateURL_Usage(t *testing.T) {
-	var errBuf bytes.Buffer
-	origErr := errWriter
-	errWriter = &errBuf
-	defer func() { errWriter = origErr }()
-
-	code := runValidateURL(nil)
-	if code != 2 {
-		t.Errorf("expected exit code 2 for no args, got %d", code)
-	}
-	if !strings.Contains(errBuf.String(), "usage") {
-		t.Errorf("expected usage in stderr, got %q", errBuf.String())
-	}
-
-	errBuf.Reset()
-	code = runValidateURL([]string{"arg1", "arg2"})
-	if code != 2 {
-		t.Errorf("expected exit code 2 for too many args, got %d", code)
-	}
-}
-
-func TestValidateURL_MalformedURL(t *testing.T) {
-	cases := []struct {
-		name    string
-		url     string
-		wantMsg string
-	}{
-		{"empty", "", "must be https"},
-		{"http scheme", "http://example.com/", "must be https"},
-		{"ftp scheme", "ftp://example.com/", "must be https"},
-		{"no scheme", "example.com", "must be https"},
-		{"user info", "https://user:pass@example.com/", "user-info"},
-	}
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			err := validateURL(tc.url)
-			if err == nil {
-				t.Errorf("expected error for URL %q, got nil", tc.url)
-				return
-			}
-			if !strings.Contains(err.Error(), tc.wantMsg) {
-				t.Errorf("error %q does not contain %q", err.Error(), tc.wantMsg)
-			}
-			var ve *validateError
-			if !isValidateError(err, &ve) {
-				t.Fatalf("expected *validateError, got %T", err)
-			}
-			if ve.code != 2 {
-				t.Errorf("expected code 2, got %d", ve.code)
-			}
-		})
-	}
-}
-
-func TestValidateURL_BlockedPrivateIP(t *testing.T) {
-	// localhost always resolves to 127.0.0.1 (loopback).
-	err := validateURL("https://localhost/")
-	if err == nil {
-		t.Skip("localhost did not resolve (network unavailable in test environment)")
-	}
-	var ve *validateError
-	if !isValidateError(err, &ve) {
-		t.Fatalf("expected *validateError, got %T: %v", err, err)
-	}
-	if ve.code != 1 && ve.code != 2 {
-		t.Errorf("expected code 1 (blocked) or 2 (dns fail), got %d: %s", ve.code, ve.message)
-	}
-	// If it resolved (code 1), the message must say "blocked".
-	if ve.code == 1 && !strings.Contains(ve.message, "blocked") {
-		t.Errorf("expected 'blocked' in message, got %q", ve.message)
-	}
-}
-
-func TestValidateURL_ExitCodes(t *testing.T) {
-	cases := []struct {
-		name     string
-		url      string
-		wantCode int
-	}{
-		{"http scheme", "http://example.com/", 2},
-		{"no scheme", "example.com", 2},
-		{"user info", "https://admin:secret@example.com/", 2},
-	}
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			err := validateURL(tc.url)
-			if err == nil {
-				t.Fatalf("expected error for %q", tc.url)
-			}
-			var ve *validateError
-			if !isValidateError(err, &ve) {
-				t.Fatalf("expected *validateError, got %T", err)
-			}
-			if ve.code != tc.wantCode {
-				t.Errorf("code = %d, want %d (url=%q, msg=%s)", ve.code, tc.wantCode, tc.url, ve.message)
-			}
-		})
-	}
-}
-
-func TestRunValidateURL_WithCapture(t *testing.T) {
-	var outBuf, errBuf bytes.Buffer
-	origOut, origErr := outWriter, errWriter
-	outWriter = &outBuf
-	errWriter = &errBuf
-	defer func() {
-		outWriter = origOut
-		errWriter = origErr
-	}()
-
-	// http:// scheme should fail with code 2.
-	code := runValidateURL([]string{"http://example.com/"})
-	if code != 2 {
-		t.Errorf("expected code 2 for http:// URL, got %d", code)
-	}
-	if !strings.Contains(errBuf.String(), "must be https") {
-		t.Errorf("expected error about https in stderr, got %q", errBuf.String())
-	}
-}

docs/DESIGN-57-yaml-persona.md

@@ -9,7 +9,7 @@ JSON is awkward for persona files that contain multi-line text (identity, severi
 - Backwards compatibility: existing JSON personas must continue to work
 - Security: protect against DoS via deeply nested YAML (AIKIDO-2024-10486)
 - Consistency: use `.yaml` extension (not `.yml`)
-- Library: use `github.com/goccy/go-yaml` v1.16.0+ (approved in CONVENTIONS.md); we implement custom AST-based depth/node-count checks for precise alias-aware validation
+- Library: use `gopkg.in/yaml.v3` (approved in CONVENTIONS.md) with explicit depth limiting
 
 ## Proposed Approach
 
@@ -33,16 +33,37 @@ func parsePersona(data []byte, source string) (*Persona, error) {
 
 ### YAML Parsing with Depth Protection
 
-We implement a custom AST-based depth/node-count walk (`checkYAMLDepth` in
+```go
-`review/persona.go`) rather than relying on library decoder options. Key design
+func unmarshalYAMLWithDepthLimit(data []byte, out any, maxDepth int) error {
-decisions:
+    var node yaml.Node
+    dec := yaml.NewDecoder(bytes.NewReader(data))
+    if err := dec.Decode(&node); err != nil {
+        return err
+    }
+    if err := checkYAMLDepth(&node, 0, maxDepth); err != nil {
+        return err
+    }
+    return node.Decode(out)
+}
 
-- **Library:** `github.com/goccy/go-yaml` with `ast.Node`-based traversal
+func checkYAMLDepth(node *yaml.Node, depth, maxDepth int) error {
-- **Dual-map tracking:** `validated` (depth-aware short-circuit) + `visiting` (cycle detection)
+    if depth > maxDepth {
-- **Node-count limit:** Conservative overcounting bounds total validation work
+        return fmt.Errorf("YAML nesting depth exceeds maximum (%d)", maxDepth)
-- **Alias-aware depth:** Aliases increment depth and are re-checked when encountered at greater depths
+    }
+    // Handle alias nodes by following the Alias pointer
+    if node.Kind == yaml.AliasNode && node.Alias != nil {
+        return checkYAMLDepth(node.Alias, depth, maxDepth)
+    }
+    for _, child := range node.Content {
+        if err := checkYAMLDepth(child, depth+1, maxDepth); err != nil {
+            return err
+        }
+    }
+    return nil
+}
+```
 
-See `review/persona.go:checkYAMLDepth` for the authoritative implementation.
+The `gopkg.in/yaml.v3` library does not have built-in depth protection, so we implement explicit depth checking by first decoding into a `yaml.Node`, walking the tree to verify depth (including alias resolution), then decoding into the target struct.
 
 ## State/Data Model
 
@@ -53,7 +74,7 @@ No new state. Same `Persona` struct, just different parsing.
 | Error | Handling |
 |-------|----------|
 | Invalid YAML syntax | Return parse error with source file |
-| Deeply nested YAML | Custom AST walk (`checkYAMLDepth`) rejects before decode |
+| Deeply nested YAML | Library rejects (v1.16.0+ fix) |
 | Unknown extension | Fall back to JSON parsing |
 | Missing required fields | Validation rejects after parse |
 

docs/DESIGN-vcs-abstraction.md

@@ -0,0 +1,268 @@
+# GitHub Support for review-bot
+
+## Goal
+
+AI code reviews on GitHub PRs using SAP AI Core as the LLM provider.
+
+## Non-Goals
+
+- Auto-detection of platform (explicit `--provider` flag is fine)
+- Unifying into one abstraction layer for its own sake
+
+## Constraints
+
+1. **Same features on both platforms** — anything review-bot does on Gitea should work on GitHub
+2. **Testable** — small interfaces, dependency injection, no global state
+3. **Interface from working code** — extract from gitea/, don't invent in vacuum
+
+---
+
+## Part 1: Feature Inventory
+
+What does review-bot actually do?
+
+### Core Review Flow
+
+| Feature | Description |
+|---------|-------------|
+| Get PR metadata | Title, body, head SHA, base ref |
+| Get PR diff | Unified diff format |
+| Get PR files | List of changed files with status |
+| Get file content | Raw file at ref |
+| List directory | Enumerate files in path |
+| Post review | Body + inline comments + verdict |
+
+### Review Management
+
+| Feature | Description |
+|---------|-------------|
+| List reviews | Get existing reviews on PR |
+| Delete review | Remove old review before re-posting |
+| Get authenticated user | Who am I? |
+
+### Platform-Specific (not in shared interface)
+
+| Feature | Gitea | GitHub |
+|---------|-------|--------|
+| Resolve comment | Yes | No equivalent |
+| Timeline API | Yes | No equivalent |
+
+These stay on gitea.Client directly. Callers that need them type-assert.
+
+---
+
+## Part 2: GitHub API Mapping
+
+| Feature | Gitea API | GitHub API |
+|---------|-----------|------------|
+| Get PR | `GET /api/v1/repos/.../pulls/{n}` | `GET /repos/.../pulls/{n}` |
+| Get diff | `.diff` suffix | `Accept: application/vnd.github.diff` header |
+| Get files | `GET .../pulls/{n}/files` | Same |
+| Get file content | `GET .../raw/{path}?ref=` | `GET .../contents/{path}?ref=` + base64 decode |
+| List directory | `GET .../contents/{path}` | Same |
+| Post review | `POST .../pulls/{n}/reviews` | Same (adapter handles comment schema) |
+| List reviews | `GET .../pulls/{n}/reviews` | Same |
+| Delete review | `DELETE .../pulls/{n}/reviews/{id}` | Same |
+| Get user | `GET /api/v1/user` | `GET /user` |
+
+---
+
+## Part 3: Interface Design
+
+**Principle:** Extract from working gitea/ code. The interface is discovered, not invented.
+
+### Small, role-based interfaces
+
+```go
+// vcs/interfaces.go
+
+type PRReader interface {
+    GetPullRequest(ctx context.Context, owner, repo string, number int) (*PullRequest, error)
+    GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error)
+    GetPullRequestFiles(ctx context.Context, owner, repo string, number int) ([]ChangedFile, error)
+}
+
+type FileReader interface {
+    GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error)
+    ListContents(ctx context.Context, owner, repo, path string) ([]ContentEntry, error)
+}
+
+type Reviewer interface {
+    PostReview(ctx context.Context, owner, repo string, number int, req ReviewRequest) (*Review, error)
+    ListReviews(ctx context.Context, owner, repo string, number int) ([]Review, error)
+    DeleteReview(ctx context.Context, owner, repo string, number int, reviewID int64) error
+}
+
+type Identity interface {
+    GetAuthenticatedUser(ctx context.Context) (string, error)
+}
+
+// Client combines all for callers that need everything
+type Client interface {
+    PRReader
+    FileReader
+    Reviewer
+    Identity
+}
+```
+
+### Types
+
+Use what gitea/ already has. Move to vcs/types.go or re-export.
+
+```go
+type PullRequest struct { ... }   // from gitea.PullRequest
+type ChangedFile struct { ... }   // from gitea.ChangedFile
+type ContentEntry struct { ... }  // from gitea.ContentEntry
+type Review struct { ... }        // from gitea.Review
+type ReviewRequest struct { ... } // new, for PostReview input
+type ReviewComment struct { ... } // from gitea.ReviewComment
+```
+
+### Adapter responsibilities
+
+Each adapter (gitea, github) handles:
+- API URL construction
+- Auth header format (`token` vs `Bearer`)
+- Request/response mapping
+- Comment schema translation (line numbers, commit IDs, etc.)
+
+---
+
+## Part 4: Test Plan
+
+### Unit Tests (mock HTTP)
+
+```
+github/
+  pr_test.go        # TestGetPullRequest, TestGetDiff, TestGetFiles
+  files_test.go     # TestGetFileContent, TestListContents
+  review_test.go    # TestPostReview, TestListReviews, TestDeleteReview
+  identity_test.go  # TestGetAuthenticatedUser
+```
+
+Per method: happy path, 404, 401, 429, malformed response.
+
+### Integration Tests
+
+Against github.com/aweiker/ai-core-review-bot:
+- Fetch real PR
+- Fetch real file
+- Post + delete review (clean up)
+
+### End-to-End
+
+Open PR on test repo, run full review-bot, verify review appears.
+
+---
+
+## Part 5: Implementation Phases
+
+### Phase 1: Extract interfaces from gitea/
+
+**Work:**
+- Create `vcs/interfaces.go` with interfaces extracted from gitea/client.go signatures
+- Create `vcs/types.go` — move or alias types from gitea/
+- Verify gitea.Client satisfies vcs.Client (compile-time check)
+
+**Exit criteria:** `var _ vcs.Client = (*gitea.Client)(nil)` compiles.
+
+---
+
+### Phase 2: Gitea adapter (if needed)
+
+**Work:**
+- If gitea.Client method signatures don't match exactly, create wrapper
+- Keep gitea/ working exactly as before
+
+**Exit criteria:** Existing tests pass. No behavior change.
+
+---
+
+### Phase 3: GitHub client — PRReader
+
+**Work:**
+- `github/client.go` — struct, constructor, HTTP helpers
+- `github/pr.go` — GetPullRequest, GetPullRequestDiff, GetPullRequestFiles
+- Unit tests
+
+**Exit criteria:** `go test ./github/...` passes for PR methods.
+
+---
+
+### Phase 4: GitHub client — FileReader
+
+**Work:**
+- `github/files.go` — GetFileContent, ListContents
+- Unit tests
+
+**Exit criteria:** Unit tests pass.
+
+---
+
+### Phase 5: GitHub client — Reviewer + Identity
+
+**Work:**
+- `github/review.go` — PostReview, ListReviews, DeleteReview
+- `github/identity.go` — GetAuthenticatedUser
+- Unit tests
+
+**Exit criteria:** Unit tests pass.
+
+---
+
+### Phase 6: Integration tests
+
+**Work:**
+- `integration/github_test.go`
+- Test against real GitHub
+
+**Exit criteria:** All integration tests pass.
+
+---
+
+### Phase 7: Wire into cmd/review-bot
+
+**Work:**
+- Add `--provider github|gitea` flag (default: gitea for backward compat)
+- Select client based on flag
+- Update to use vcs interfaces where it makes sense
+
+**Exit criteria:**
+- `./review-bot --provider github ...` works
+- `./review-bot --provider gitea ...` works (same as before)
+- Existing Gitea workflows unchanged
+
+---
+
+### Phase 8: GitHub Actions workflow + releases
+
+**Work:**
+- `.github/workflows/ci.yml` — test on PR
+- `.github/workflows/release.yml` — publish binary to GitHub releases
+- `.github/actions/review/action.yml` — composite action
+- Action downloads binary from github.com/aweiker/ai-core-review-bot releases
+
+**Exit criteria:** 
+- CI runs on github.com/aweiker/ai-core-review-bot
+- Release creates downloadable binary
+- Review action posts review successfully
+
+---
+
+## Part 6: Decisions
+
+| Question | Decision |
+|----------|----------|
+| Auth token | Workflow `GITHUB_TOKEN` (automatic) |
+| Binary distribution | GitHub releases on aweiker/ai-core-review-bot |
+| Comment schema | Adapter's job — translate ReviewComment to platform format |
+| Default provider | `gitea` for backward compatibility |
+| Shared types | vcs/types.go (extracted from gitea/) |
+| Platform-specific features | Stay on concrete client, not interface |
+
+---
+
+## Summary
+
+8 phases. Start by extracting interfaces from working gitea/ code, not inventing them. GitHub implements the same interfaces. Each phase has clear exit criteria.

gitea/adapter.go

@@ -0,0 +1,232 @@
+package gitea
+
+import (
+	"context"
+	"fmt"
+
+	"gitea.weiker.me/rodin/review-bot/vcs"
+)
+
+// Adapter wraps a gitea.Client and satisfies the vcs.Client interface.
+// It handles translation between GitHub-canonical diff positions and Gitea
+// line numbers, and between canonical review event strings and Gitea-native values.
+type Adapter struct {
+	client *Client
+}
+
+// Compile-time interface conformance assertion.
+var _ vcs.Client = (*Adapter)(nil)
+
+// NewAdapter creates a new Adapter wrapping the given gitea Client.
+func NewAdapter(client *Client) *Adapter {
+	return &Adapter{client: client}
+}
+
+// Underlying returns the wrapped gitea.Client for Gitea-specific operations
+// that have no vcs.Client equivalent (resolve comment, timeline, supersede flow).
+func (a *Adapter) Underlying() *Client {
+	return a.client
+}
+
+// --- PRReader ---
+
+// GetPullRequest maps gitea.PullRequest to vcs.PullRequest.
+func (a *Adapter) GetPullRequest(ctx context.Context, owner, repo string, number int) (*vcs.PullRequest, error) {
+	pr, err := a.client.GetPullRequest(ctx, owner, repo, number)
+	if err != nil {
+		return nil, fmt.Errorf("get pull request: %w", err)
+	}
+	return &vcs.PullRequest{
+		Number: number,
+		Title:  pr.Title,
+		Body:   pr.Body,
+		Head: vcs.HeadRef{
+			SHA: pr.Head.Sha,
+			Ref: pr.Head.Ref,
+		},
+		Base: vcs.BaseRef{
+			Ref: pr.Base.Ref,
+		},
+	}, nil
+}
+
+// GetPullRequestDiff is a pass-through to the underlying client.
+func (a *Adapter) GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error) {
+	return a.client.GetPullRequestDiff(ctx, owner, repo, number)
+}
+
+// GetPullRequestFiles maps []gitea.ChangedFile to []vcs.ChangedFile.
+// Patch field is omitted (zero-value) since Gitea's /pulls/{n}/files does not return patch text.
+func (a *Adapter) GetPullRequestFiles(ctx context.Context, owner, repo string, number int) ([]vcs.ChangedFile, error) {
+	files, err := a.client.GetPullRequestFiles(ctx, owner, repo, number)
+	if err != nil {
+		return nil, err
+	}
+	result := make([]vcs.ChangedFile, len(files))
+	for i, f := range files {
+		result[i] = vcs.ChangedFile{
+			Filename: f.Filename,
+			Status:   f.Status,
+		}
+	}
+	return result, nil
+}
+
+// GetFileContentAtRef is a pass-through to the underlying client.
+func (a *Adapter) GetFileContentAtRef(ctx context.Context, owner, repo, path, ref string) (string, error) {
+	return a.client.GetFileContentAtRef(ctx, owner, repo, path, ref)
+}
+
+// GetCommitStatuses maps []gitea.CommitStatus to []vcs.CommitStatus.
+func (a *Adapter) GetCommitStatuses(ctx context.Context, owner, repo, sha string) ([]vcs.CommitStatus, error) {
+	statuses, err := a.client.GetCommitStatuses(ctx, owner, repo, sha)
+	if err != nil {
+		return nil, err
+	}
+	result := make([]vcs.CommitStatus, len(statuses))
+	for i, s := range statuses {
+		result[i] = vcs.CommitStatus{
+			Status:      s.Status,
+			Context:     s.Context,
+			Description: s.Description,
+			TargetURL:   s.TargetURL,
+		}
+	}
+	return result, nil
+}
+
+// --- FileReader ---
+
+// GetFileContent delegates to the underlying client, routing to the ref-aware
+// variant when ref is non-empty.
+func (a *Adapter) GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error) {
+	if ref != "" {
+		return a.client.GetFileContentRef(ctx, owner, repo, path, ref)
+	}
+	return a.client.GetFileContent(ctx, owner, repo, path)
+}
+
+// ListContents maps []gitea.ContentEntry to []vcs.ContentEntry.
+func (a *Adapter) ListContents(ctx context.Context, owner, repo, path string) ([]vcs.ContentEntry, error) {
+	entries, err := a.client.ListContents(ctx, owner, repo, path)
+	if err != nil {
+		return nil, err
+	}
+	result := make([]vcs.ContentEntry, len(entries))
+	for i, e := range entries {
+		result[i] = vcs.ContentEntry{
+			Name: e.Name,
+			Path: e.Path,
+			Type: e.Type,
+		}
+	}
+	return result, nil
+}
+
+// --- Reviewer ---
+
+// translateEvent translates a vcs.ReviewEvent (GitHub-canonical) to a Gitea-native event string.
+func translateEvent(event vcs.ReviewEvent) string {
+	switch event {
+	case vcs.ReviewEventApprove:
+		return "APPROVED"
+	case vcs.ReviewEventRequestChanges:
+		return "REQUEST_CHANGES"
+	case vcs.ReviewEventComment:
+		return "COMMENT"
+	default:
+		// Unknown events pass through as-is. This is intentional: new event types
+		// added to vcs.ReviewEvent will still be forwarded without a code change here,
+		// and Gitea will reject truly invalid values with a clear API error.
+		return string(event)
+	}
+}
+
+// PostReview translates vcs.ReviewRequest to the Gitea-native format.
+// It fetches the PR diff, builds a position-to-line map, and translates each
+// ReviewComment.Position (GitHub diff-position) to a Gitea new_position (line number).
+func (a *Adapter) PostReview(ctx context.Context, owner, repo string, number int, req vcs.ReviewRequest) (*vcs.Review, error) {
+	event := translateEvent(req.Event)
+
+	var giteaComments []ReviewComment
+	if len(req.Comments) > 0 {
+		// Fetch diff to build position → line number map.
+		// The diff is fetched unconditionally when comments exist. This adds latency
+		// for reviews with inline comments but keeps the implementation simple — caching
+		// the diff across calls would add complexity for minimal gain since PostReview
+		// is called at most once per review cycle.
+		diff, err := a.client.GetPullRequestDiff(ctx, owner, repo, number)
+		if err != nil {
+			return nil, fmt.Errorf("fetch diff for position translation: %w", err)
+		}
+
+		posMap := BuildPositionToLineMap(diff)
+
+		for _, c := range req.Comments {
+			lineNum, err := posMap.Translate(c.Path, c.Position)
+			if err != nil {
+				return nil, fmt.Errorf("translate position %d in %s: %w", c.Position, c.Path, err)
+			}
+			// CommitID from vcs.ReviewComment is intentionally not forwarded:
+			// Gitea review comments are pinned to the PR head SHA automatically,
+			// and the CreatePullReview API has no per-comment commit_id field.
+			giteaComments = append(giteaComments, ReviewComment{
+				Path:        c.Path,
+				NewPosition: int64(lineNum),
+				Body:        c.Body,
+			})
+		}
+	}
+
+	review, err := a.client.PostReview(ctx, owner, repo, number, event, req.Body, giteaComments)
+	if err != nil {
+		return nil, fmt.Errorf("post review: %w", err)
+	}
+
+	return &vcs.Review{
+		ID:       review.ID,
+		Body:     review.Body,
+		User:     vcs.UserInfo{Login: review.User.Login},
+		State:    review.State,
+		Stale:    review.Stale,
+		CommitID: review.CommitID,
+	}, nil
+}
+
+// ListReviews maps []gitea.Review to []vcs.Review.
+func (a *Adapter) ListReviews(ctx context.Context, owner, repo string, number int) ([]vcs.Review, error) {
+	reviews, err := a.client.ListReviews(ctx, owner, repo, number)
+	if err != nil {
+		return nil, err
+	}
+	result := make([]vcs.Review, len(reviews))
+	for i, r := range reviews {
+		result[i] = vcs.Review{
+			ID:       r.ID,
+			Body:     r.Body,
+			User:     vcs.UserInfo{Login: r.User.Login},
+			State:    r.State,
+			Stale:    r.Stale,
+			CommitID: r.CommitID,
+		}
+	}
+	return result, nil
+}
+
+// DeleteReview is a pass-through to the underlying client.
+func (a *Adapter) DeleteReview(ctx context.Context, owner, repo string, number int, reviewID int64) error {
+	return a.client.DeleteReview(ctx, owner, repo, number, reviewID)
+}
+
+// DismissReview deletes the review. Gitea supports full deletion of any review state.
+// The message parameter is intentionally unused — Gitea deletion has no dismissal message.
+func (a *Adapter) DismissReview(ctx context.Context, owner, repo string, number int, reviewID int64, message string) error {
+	return a.client.DeleteReview(ctx, owner, repo, number, reviewID)
+}
+
+// --- Identity ---
+
+// GetAuthenticatedUser is a pass-through to the underlying client.
+func (a *Adapter) GetAuthenticatedUser(ctx context.Context) (string, error) {
+	return a.client.GetAuthenticatedUser(ctx)
+}

gitea/adapter_test.go

@@ -0,0 +1,388 @@
+package gitea_test
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"gitea.weiker.me/rodin/review-bot/gitea"
+	"gitea.weiker.me/rodin/review-bot/vcs"
+)
+
+func TestAdapter_GetPullRequest(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]any{
+			"title": "Test PR",
+			"body":  "PR body",
+			"head": map[string]any{
+				"sha": "abc123",
+				"ref": "feature-branch",
+			},
+			"base": map[string]any{
+				"ref": "main",
+			},
+		})
+	}))
+	defer server.Close()
+
+	client := gitea.NewClient(server.URL, "token")
+	adapter := gitea.NewAdapter(client)
+
+	pr, err := adapter.GetPullRequest(context.Background(), "owner", "repo", 42)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if pr.Number != 42 {
+		t.Errorf("Number = %d, want 42", pr.Number)
+	}
+	if pr.Title != "Test PR" {
+		t.Errorf("Title = %q, want %q", pr.Title, "Test PR")
+	}
+	if pr.Body != "PR body" {
+		t.Errorf("Body = %q, want %q", pr.Body, "PR body")
+	}
+	if pr.Head.SHA != "abc123" {
+		t.Errorf("Head.SHA = %q, want %q", pr.Head.SHA, "abc123")
+	}
+	if pr.Head.Ref != "feature-branch" {
+		t.Errorf("Head.Ref = %q, want %q", pr.Head.Ref, "feature-branch")
+	}
+	if pr.Base.Ref != "main" {
+		t.Errorf("Base.Ref = %q, want %q", pr.Base.Ref, "main")
+	}
+}
+
+func TestAdapter_GetPullRequestFiles(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode([]map[string]any{
+			{"filename": "main.go", "status": "modified"},
+			{"filename": "new.go", "status": "added"},
+		})
+	}))
+	defer server.Close()
+
+	client := gitea.NewClient(server.URL, "token")
+	adapter := gitea.NewAdapter(client)
+
+	files, err := adapter.GetPullRequestFiles(context.Background(), "owner", "repo", 1)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(files) != 2 {
+		t.Fatalf("got %d files, want 2", len(files))
+	}
+	if files[0].Filename != "main.go" || files[0].Status != "modified" {
+		t.Errorf("files[0] = %+v", files[0])
+	}
+	if files[1].Filename != "new.go" || files[1].Status != "added" {
+		t.Errorf("files[1] = %+v", files[1])
+	}
+}
+
+func TestAdapter_ListReviews(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode([]map[string]any{
+			{
+				"id":        1,
+				"body":      "LGTM",
+				"user":      map[string]any{"login": "reviewer1"},
+				"state":     "APPROVED",
+				"stale":     false,
+				"commit_id": "abc123",
+			},
+			{
+				"id":        2,
+				"body":      "Needs work",
+				"user":      map[string]any{"login": "reviewer2"},
+				"state":     "REQUEST_CHANGES",
+				"stale":     true,
+				"commit_id": "def456",
+			},
+		})
+	}))
+	defer server.Close()
+
+	client := gitea.NewClient(server.URL, "token")
+	adapter := gitea.NewAdapter(client)
+
+	reviews, err := adapter.ListReviews(context.Background(), "owner", "repo", 1)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(reviews) != 2 {
+		t.Fatalf("got %d reviews, want 2", len(reviews))
+	}
+	if reviews[0].ID != 1 || reviews[0].Body != "LGTM" || reviews[0].User.Login != "reviewer1" {
+		t.Errorf("reviews[0] = %+v", reviews[0])
+	}
+	if reviews[0].State != "APPROVED" || reviews[0].Stale || reviews[0].CommitID != "abc123" {
+		t.Errorf("reviews[0] state/stale/commit = %v/%v/%v", reviews[0].State, reviews[0].Stale, reviews[0].CommitID)
+	}
+	if reviews[1].ID != 2 || !reviews[1].Stale || reviews[1].State != "REQUEST_CHANGES" {
+		t.Errorf("reviews[1] = %+v", reviews[1])
+	}
+}
+
+func TestAdapter_GetCommitStatuses(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode([]map[string]any{
+			{
+				"status":      "success",
+				"context":     "ci/test",
+				"description": "All tests pass",
+				"target_url":  "https://ci.example.com/1",
+			},
+		})
+	}))
+	defer server.Close()
+
+	client := gitea.NewClient(server.URL, "token")
+	adapter := gitea.NewAdapter(client)
+
+	statuses, err := adapter.GetCommitStatuses(context.Background(), "owner", "repo", "abc123")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(statuses) != 1 {
+		t.Fatalf("got %d statuses, want 1", len(statuses))
+	}
+	if statuses[0].Status != "success" {
+		t.Errorf("Status = %q, want %q", statuses[0].Status, "success")
+	}
+	if statuses[0].Context != "ci/test" {
+		t.Errorf("Context = %q, want %q", statuses[0].Context, "ci/test")
+	}
+	if statuses[0].Description != "All tests pass" {
+		t.Errorf("Description = %q, want %q", statuses[0].Description, "All tests pass")
+	}
+	if statuses[0].TargetURL != "https://ci.example.com/1" {
+		t.Errorf("TargetURL = %q, want %q", statuses[0].TargetURL, "https://ci.example.com/1")
+	}
+}
+
+func TestAdapter_PostReview_EventTranslation(t *testing.T) {
+	tests := []struct {
+		name      string
+		event     vcs.ReviewEvent
+		wantEvent string
+	}{
+		{"APPROVE becomes APPROVED", vcs.ReviewEventApprove, "APPROVED"},
+		{"REQUEST_CHANGES stays", vcs.ReviewEventRequestChanges, "REQUEST_CHANGES"},
+		{"COMMENT stays", vcs.ReviewEventComment, "COMMENT"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var gotEvent string
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.Header().Set("Content-Type", "application/json")
+				var payload struct {
+					Event string `json:"event"`
+				}
+				json.NewDecoder(r.Body).Decode(&payload)
+				gotEvent = payload.Event
+				json.NewEncoder(w).Encode(map[string]any{
+					"id":   1,
+					"body": "test",
+					"user": map[string]any{"login": "bot"},
+				})
+			}))
+			defer server.Close()
+
+			client := gitea.NewClient(server.URL, "token")
+			adapter := gitea.NewAdapter(client)
+
+			_, err := adapter.PostReview(context.Background(), "owner", "repo", 1, vcs.ReviewRequest{
+				Body:  "test",
+				Event: tt.event,
+				// No comments → no diff fetch needed
+			})
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			if gotEvent != tt.wantEvent {
+				t.Errorf("event = %q, want %q", gotEvent, tt.wantEvent)
+			}
+		})
+	}
+}
+
+func TestAdapter_PostReview_WithComments_PositionTranslation(t *testing.T) {
+	diff := `diff --git a/main.go b/main.go
+--- a/main.go
++++ b/main.go
+@@ -1,3 +1,4 @@
+ package main
+ 
++// new comment at line 3
+ func main() {}
+`
+	var gotComments []struct {
+		Path        string `json:"path"`
+		NewPosition int64  `json:"new_position"`
+		Body        string `json:"body"`
+	}
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		if strings.HasSuffix(r.URL.Path, ".diff") {
+			// Diff request
+			w.Write([]byte(diff))
+			return
+		}
+		if strings.HasSuffix(r.URL.Path, "/reviews") {
+			// Review post
+			var payload struct {
+				Comments []struct {
+					Path        string `json:"path"`
+					NewPosition int64  `json:"new_position"`
+					Body        string `json:"body"`
+				} `json:"comments"`
+			}
+			json.NewDecoder(r.Body).Decode(&payload)
+			gotComments = payload.Comments
+			json.NewEncoder(w).Encode(map[string]any{
+				"id":   1,
+				"body": "review",
+				"user": map[string]any{"login": "bot"},
+			})
+			return
+		}
+		t.Errorf("unexpected request: %s %s", r.Method, r.URL.Path)
+		w.WriteHeader(http.StatusNotFound)
+	}))
+	defer server.Close()
+
+	client := gitea.NewClient(server.URL, "token")
+	adapter := gitea.NewAdapter(client)
+
+	// Position 4 in this diff is "+// new comment at line 3" → new line 3
+	_, err := adapter.PostReview(context.Background(), "owner", "repo", 1, vcs.ReviewRequest{
+		Body:  "review",
+		Event: vcs.ReviewEventRequestChanges,
+		Comments: []vcs.ReviewComment{
+			{
+				Path:     "main.go",
+				Position: 4,
+				CommitID: "abc123",
+				Body:     "needs fix",
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if len(gotComments) != 1 {
+		t.Fatalf("got %d comments, want 1", len(gotComments))
+	}
+	if gotComments[0].Path != "main.go" {
+		t.Errorf("path = %q, want %q", gotComments[0].Path, "main.go")
+	}
+	if gotComments[0].NewPosition != 3 {
+		t.Errorf("new_position = %d, want 3", gotComments[0].NewPosition)
+	}
+	if gotComments[0].Body != "needs fix" {
+		t.Errorf("body = %q, want %q", gotComments[0].Body, "needs fix")
+	}
+}
+
+func TestAdapter_DismissReview(t *testing.T) {
+	var deleteCalled bool
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == http.MethodDelete {
+			deleteCalled = true
+			w.WriteHeader(204)
+			return
+		}
+		w.WriteHeader(404)
+	}))
+	defer server.Close()
+
+	client := gitea.NewClient(server.URL, "token")
+	adapter := gitea.NewAdapter(client)
+
+	err := adapter.DismissReview(context.Background(), "owner", "repo", 1, 99, "stale review")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if !deleteCalled {
+		t.Error("expected delete to be called")
+	}
+}
+
+func TestAdapter_Underlying(t *testing.T) {
+	client := gitea.NewClient("http://example.com", "token")
+	adapter := gitea.NewAdapter(client)
+	if adapter.Underlying() != client {
+		t.Error("Underlying() should return the wrapped client")
+	}
+}
+
+func TestAdapter_ListContents(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode([]map[string]any{
+			{"name": "main.go", "path": "src/main.go", "type": "file"},
+			{"name": "util", "path": "src/util", "type": "dir"},
+		})
+	}))
+	defer server.Close()
+
+	client := gitea.NewClient(server.URL, "token")
+	adapter := gitea.NewAdapter(client)
+
+	entries, err := adapter.ListContents(context.Background(), "owner", "repo", "src")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(entries) != 2 {
+		t.Fatalf("got %d entries, want 2", len(entries))
+	}
+	if entries[0].Name != "main.go" || entries[0].Type != "file" {
+		t.Errorf("entries[0] = %+v", entries[0])
+	}
+	if entries[1].Name != "util" || entries[1].Type != "dir" {
+		t.Errorf("entries[1] = %+v", entries[1])
+	}
+}
+
+func TestAdapter_GetFileContent_RefRouting(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// When ref is provided, the URL should contain ?ref=
+		if r.URL.RawQuery != "" && strings.Contains(r.URL.RawQuery, "ref=") {
+			w.Write([]byte("content-at-ref"))
+		} else {
+			w.Write([]byte("content-default"))
+		}
+	}))
+	defer server.Close()
+
+	client := gitea.NewClient(server.URL, "token")
+	adapter := gitea.NewAdapter(client)
+
+	// Empty ref → routes to GetFileContent (no ?ref= query param)
+	got, err := adapter.GetFileContent(context.Background(), "owner", "repo", "main.go", "")
+	if err != nil {
+		t.Fatalf("GetFileContent(ref=\"\"): %v", err)
+	}
+	if got != "content-default" {
+		t.Errorf("GetFileContent(ref=\"\") = %q, want %q", got, "content-default")
+	}
+
+	// Non-empty ref → routes to GetFileContentRef (with ?ref= query param)
+	got, err = adapter.GetFileContent(context.Background(), "owner", "repo", "main.go", "abc123")
+	if err != nil {
+		t.Fatalf("GetFileContent(ref=\"abc123\"): %v", err)
+	}
+	if got != "content-at-ref" {
+		t.Errorf("GetFileContent(ref=\"abc123\") = %q, want %q", got, "content-at-ref")
+	}
+}

gitea/client.go

@@ -11,7 +11,6 @@ import (
 	"fmt"
 	"io"
 	"log/slog"
-	"math"
 	"net"
 	"net/http"
 	"net/url"
@@ -48,12 +47,6 @@ func IsServerError(err error) bool {
 	return errors.As(err, &apiErr) && apiErr.StatusCode >= 500 && apiErr.StatusCode < 600
 }
 
-// DefaultMaxDiffSize is the default maximum diff size in bytes (10 MB).
-const DefaultMaxDiffSize = 10 * 1024 * 1024
-
-// ErrDiffTooLarge is returned when a PR diff exceeds the configured MaxDiffSize.
-var ErrDiffTooLarge = errors.New("diff size exceeds maximum allowed size")
-
 // Client interacts with the Gitea API.
 // A Client is safe for concurrent use by multiple goroutines.
 type Client struct {
@@ -68,152 +61,20 @@ type Client struct {
 	// This field must be configured before the first request is made.
 	// Modifying it while requests are in flight is not safe.
 	RetryBackoff []time.Duration
-
-	// MaxDiffSize is the maximum number of bytes allowed when fetching a PR diff.
-	// If zero, defaults to DefaultMaxDiffSize (10 MB). Set to any negative value
-	// (or math.MaxInt64) to disable the limit.
-	//
-	// This field must be configured before the first request is made.
-	// Modifying it while requests are in flight is not safe.
-	MaxDiffSize int64
-}
-
-// defaultCheckRedirect is the redirect policy used by NewClient.
-// NOTE: This function is intentionally duplicated in github/client.go (and vice versa)
-// because the packages are separate. Changes here must be mirrored there.
-// It rejects HTTPS->HTTP protocol downgrades (to prevent plaintext leakage)
-// and cross-host redirects (to prevent following responses from untrusted
-// endpoints). Same-host, same-or-upgraded-scheme redirects are allowed.
-func defaultCheckRedirect(req *http.Request, via []*http.Request) error {
-	if len(via) >= 10 {
-		return fmt.Errorf("stopped after 10 redirects")
-	}
-	// Guard for direct invocation in tests and any future callers;
-	// net/http guarantees len(via) >= 1 during actual redirects.
-	if len(via) == 0 {
-		return nil
-	}
-	prev := via[len(via)-1]
-	// Reject protocol downgrade: HTTPS->HTTP leaks request metadata over plaintext.
-	if prev.URL.Scheme == "https" && req.URL.Scheme == "http" {
-		return fmt.Errorf("refusing redirect: HTTPS to HTTP downgrade (%s -> %s)", prev.URL.Host, req.URL.Host)
-	}
-	// Reject cross-host redirect entirely to avoid consuming responses
-	// from untrusted endpoints.
-	if req.URL.Host != prev.URL.Host {
-		return fmt.Errorf("refusing redirect: cross-host (%s -> %s)", prev.URL.Host, req.URL.Host)
-	}
-	return nil
-}
-
-// safeDialContext is the default DialContext for NewClient.
-// It resolves the hostname and checks every returned IP against the blocked
-// CIDR list before establishing a connection. This prevents SSRF attacks
-// where user-supplied URLs resolve to internal/private addresses.
-//
-// After validating all IPs, we dial the first resolved IP directly to avoid
-// a second DNS lookup (which could return a different IP in a DNS rebinding
-// attack). This narrows — but does not fully eliminate — the DNS rebinding
-// window to the time between LookupIPAddr and DialContext.
-//
-// If the host is already an IP literal, LookupIPAddr returns it directly
-// (no DNS query issued), so IP literals like https://127.0.0.1/ are blocked.
-func safeDialContext(ctx context.Context, network, addr string) (net.Conn, error) {
-	host, port, err := net.SplitHostPort(addr)
-	if err != nil {
-		return nil, fmt.Errorf("safeDialContext: invalid address %q: %w", addr, err)
-	}
-	addrs, err := net.DefaultResolver.LookupIPAddr(ctx, host)
-	if err != nil {
-		return nil, fmt.Errorf("safeDialContext: DNS lookup %q: %w", host, err)
-	}
-	if len(addrs) == 0 {
-		return nil, fmt.Errorf("safeDialContext: no addresses returned for %q", host)
-	}
-	for _, a := range addrs {
-		if IsBlockedIP(a.IP) {
-			return nil, fmt.Errorf("safeDialContext: blocked: %q resolves to private/reserved IP %s", host, a.IP)
-		}
-	}
-	// Try each resolved IP in order, returning the first successful connection.
-	// Fallback is important when a hostname resolves to multiple IPs and the first
-	// is temporarily unreachable. All IPs were already validated above, so dialing
-	// any of them is safe.
-	//
-	// Timeout: 10s per the design (PLAN.md); the outer http.Client has a 30s
-	// total timeout, but the per-dial timeout ensures a slow TCP connect on one IP
-	// doesn't consume the budget needed to try others.
-	d := &net.Dialer{Timeout: 10 * time.Second}
-	var lastErr error
-	for _, a := range addrs {
-		conn, err := d.DialContext(ctx, network, net.JoinHostPort(a.IP.String(), port))
-		if err == nil {
-			return conn, nil
-		}
-		lastErr = err
-	}
-	return nil, fmt.Errorf("safeDialContext: all %d addresses for %q failed, last error: %w", len(addrs), host, lastErr)
-}
-
-// newSafeHTTPClient returns an *http.Client with the SSRF-blocking safeDialContext
-// transport and the cross-host redirect rejection policy.
-//
-// We clone http.DefaultTransport to preserve its production-ready defaults
-// (ProxyFromEnvironment, TLSHandshakeTimeout, IdleConnTimeout, connection
-// pooling, HTTP/2 support) and override only DialContext with safeDialContext.
-func newSafeHTTPClient() *http.Client {
-	transport := http.DefaultTransport.(*http.Transport).Clone()
-	transport.DialContext = safeDialContext
-	return &http.Client{
-		Timeout:       30 * time.Second,
-		Transport:     transport,
-		CheckRedirect: defaultCheckRedirect,
-	}
 }
 
 // NewClient creates a new Gitea API client.
-//
-// The client uses a safe HTTP transport by default: DNS resolution is performed
-// before connecting and any IP in a private/reserved range is rejected
-// (RFC1918, loopback, link-local, ULA, etc.). Cross-host and HTTPS→HTTP
-// redirects are also rejected.
-//
-// For tests that use httptest.NewServer (which listens on 127.0.0.1), call
-// WithUnsafeDialer() to bypass the IP check.
 func NewClient(baseURL, token string) *Client {
 	return &Client{
 		baseURL: strings.TrimRight(baseURL, "/"),
 		token:   token,
-		http:    newSafeHTTPClient(),
+		http:    &http.Client{Timeout: 30 * time.Second},
 	}
 }
 
-// WithUnsafeDialer returns the client configured with a plain HTTP client that
-// has no IP-level SSRF protection. It preserves the redirect-rejection policy.
-//
-// This MUST only be used in tests. Production code must never call this method.
-func (c *Client) WithUnsafeDialer() *Client {
-	c.http = &http.Client{
-		Timeout:       30 * time.Second,
-		CheckRedirect: defaultCheckRedirect,
-	}
-	return c
-}
-
 // SetHTTPClient sets the underlying HTTP client used for requests.
-// This is intended for test setup only to inject mock transports; it must be
+// This is intended for testing to inject mock transports.
-// called before any goroutines issue requests.
-//
-// Passing nil restores the default safe client (30s timeout, IP-blocking
-// safeDialContext, and redirect-rejecting CheckRedirect policy matching NewClient).
-//
-// Callers providing a non-nil client are responsible for configuring a safe
-// CheckRedirect policy. Without one, the default net/http behavior will follow
-// redirects and may forward the Authorization header to untrusted hosts.
 func (c *Client) SetHTTPClient(hc *http.Client) {
-	if hc == nil {
-		hc = newSafeHTTPClient()
-	}
 	c.http = hc
 }
 
@@ -225,6 +86,9 @@ type PullRequest struct {
 		Sha string `json:"sha"`
 		Ref string `json:"ref"`
 	} `json:"head"`
+	Base struct {
+		Ref string `json:"ref"`
+	} `json:"base"`
 }
 
 // CommitStatus represents a single CI status entry.
@@ -264,32 +128,13 @@ func (c *Client) GetPullRequest(ctx context.Context, owner, repo string, number
 }
 
 // GetPullRequestDiff fetches the unified diff for a PR.
-// It enforces MaxDiffSize to prevent unbounded memory allocation.
-// Returns ErrDiffTooLarge if the diff exceeds the configured limit.
 func (c *Client) GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error) {
 	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d.diff", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number)
-
-	maxSize := c.MaxDiffSize
-	if maxSize == 0 {
-		maxSize = DefaultMaxDiffSize
-	}
-
-	// When the limit is disabled (negative) or set to math.MaxInt64 (which
-	// would overflow the +1 detection and silently disable enforcement),
-	// use the standard unlimited doGet path.
-	if maxSize < 0 || maxSize == math.MaxInt64 {
 	body, err := c.doGet(ctx, reqURL)
 	if err != nil {
 		return "", fmt.Errorf("fetch diff: %w", err)
 	}
 	return string(body), nil
-	}
-
-	body, err := c.doGetLimited(ctx, reqURL, maxSize)
-	if err != nil {
-		return "", fmt.Errorf("fetch diff: %w", err)
-	}
-	return string(body), nil
 }
 
 // GetPullRequestFiles fetches the list of files changed in a PR.
@@ -341,22 +186,18 @@ func (c *Client) GetFileContentRef(ctx context.Context, owner, repo, filepath, r
 }
 
 // PostReview submits a review to a PR and returns the created review.
-// event should be one of "APPROVED", "REQUEST_CHANGES", or "COMMENT".
+// event should be "APPROVED" or "REQUEST_CHANGES".
-// commitID anchors the review to a specific commit SHA. If empty, Gitea
-// defaults to the current PR head.
 // comments are optional inline comments attached to specific lines.
-func (c *Client) PostReview(ctx context.Context, owner, repo string, number int, event, body, commitID string, comments []ReviewComment) (*Review, error) {
+func (c *Client) PostReview(ctx context.Context, owner, repo string, number int, event, body string, comments []ReviewComment) (*Review, error) {
 	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d/reviews", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number)
 
 	payload := struct {
 		Body     string          `json:"body"`
 		Event    string          `json:"event"`
-		CommitID string          `json:"commit_id,omitempty"`
 		Comments []ReviewComment `json:"comments,omitempty"`
 	}{
 		Body:     body,
 		Event:    event,
-		CommitID: commitID,
 		Comments: comments,
 	}
 
@@ -454,9 +295,9 @@ func isRetriableSyscallError(err error) bool {
 	return true
 }
 
-// redactURL strips query parameters and userinfo credentials from a URL for
+// redactURL strips query parameters from a URL for safe logging.
-// safe logging. This prevents accidental exposure of sensitive data (tokens in
+// This prevents accidental exposure of sensitive data that future callers
-// query strings, or user:pass in the authority) in log output.
+// might pass via query strings.
 func redactURL(rawURL string) string {
 	parsed, err := url.Parse(rawURL)
 	if err != nil {
@@ -464,9 +305,6 @@ func redactURL(rawURL string) string {
 		// potentially logging something sensitive.
 		return "[invalid URL]"
 	}
-	if parsed.User != nil {
-		parsed.User = url.User("REDACTED")
-	}
 	if parsed.RawQuery != "" {
 		parsed.RawQuery = "[redacted]"
 	}
@@ -487,12 +325,10 @@ func sanitizeErrorForLog(err error) string {
 	return err.Error()
 }
 
-// doGetWithReader performs an HTTP GET request with retry on 5xx errors and
+// doGet performs an HTTP GET request with retry on 5xx errors and temporary
-// temporary network errors. Retries up to 3 times with exponential backoff
+// network errors. Retries up to 3 times with exponential backoff (1s, 2s delays
-// (1s, 2s delays by default; configurable via Client.RetryBackoff for testing).
+// by default; configurable via Client.RetryBackoff for testing).
-// The readBody function is called with the response body on success (2xx) and
+func (c *Client) doGet(ctx context.Context, reqURL string) ([]byte, error) {
-// is responsible for reading and closing it.
-func (c *Client) doGetWithReader(ctx context.Context, reqURL string, readBody func(io.ReadCloser) ([]byte, error)) ([]byte, error) {
 	const maxAttempts = 3
 	// backoff[i] is the delay before attempt i+1 (i.e., after attempt i fails).
 	// First attempt (i=0) has no delay; retries wait 1s then 2s by default.
@@ -557,7 +393,12 @@ func (c *Client) doGetWithReader(ctx context.Context, reqURL string, readBody fu
 			return nil, lastErr
 		}
 		if resp.StatusCode >= 200 && resp.StatusCode < 300 {
-			return readBody(resp.Body)
+			body, err := io.ReadAll(resp.Body)
+			resp.Body.Close()
+			if err != nil {
+				return nil, err
+			}
+			return body, nil
 		}
 
 		// Error path: limit how much we read from potentially malicious server
@@ -575,39 +416,6 @@ func (c *Client) doGetWithReader(ctx context.Context, reqURL string, readBody fu
 	return nil, lastErr
 }
 
-// doGet performs an HTTP GET request with retry, reading the full response body.
-func (c *Client) doGet(ctx context.Context, reqURL string) ([]byte, error) {
-	return c.doGetWithReader(ctx, reqURL, func(body io.ReadCloser) ([]byte, error) {
-		defer body.Close()
-		return io.ReadAll(body)
-	})
-}
-
-// doGetLimited performs an HTTP GET request with retry but enforces a maximum
-// response body size. Returns ErrDiffTooLarge if the response exceeds maxBytes.
-// It reads maxBytes+1 (clamped to avoid overflow) to detect truncation without
-// buffering the entire body.
-func (c *Client) doGetLimited(ctx context.Context, reqURL string, maxBytes int64) ([]byte, error) {
-	return c.doGetWithReader(ctx, reqURL, func(body io.ReadCloser) ([]byte, error) {
-		defer body.Close()
-		// Read up to maxBytes+1 to detect overflow.
-		// Clamp to prevent integer overflow when maxBytes == math.MaxInt64.
-		limitBytes := maxBytes + 1
-		if limitBytes <= 0 {
-			limitBytes = math.MaxInt64
-		}
-		limited := io.LimitReader(body, limitBytes)
-		data, err := io.ReadAll(limited)
-		if err != nil {
-			return nil, err
-		}
-		if int64(len(data)) > maxBytes {
-			return nil, fmt.Errorf("%w: response exceeds %d bytes", ErrDiffTooLarge, maxBytes)
-		}
-		return data, nil
-	})
-}
-
 // escapePath escapes each segment of a relative file path for use in URLs.
 // Slashes are preserved as path separators; other special characters are escaped.
 // Input should be a relative path (no leading slash). Already-encoded segments
@@ -1026,3 +834,15 @@ func (c *Client) ResolveComment(ctx context.Context, owner, repo string, comment
 	}
 	return nil
 }
+
+// DismissReview dismisses a review on a pull request.
+// This is a stub for the vcs.Reviewer interface; full implementation is Phase 2.
+func (c *Client) DismissReview(ctx context.Context, owner, repo string, number int, reviewID int64, message string) error {
+	return fmt.Errorf("dismiss review %d on %s/%s#%d: %w", reviewID, owner, repo, number, errors.ErrUnsupported)
+}
+
+// GetFileContentAtRef fetches a file at a specific ref from a repo.
+// This delegates to GetFileContentRef for the Gitea implementation.
+func (c *Client) GetFileContentAtRef(ctx context.Context, owner, repo, path, ref string) (string, error) {
+	return c.GetFileContentRef(ctx, owner, repo, path, ref)
+}

gitea/client_test.go

@@ -9,7 +9,6 @@ import (
 	"net"
 	"net/http"
 	"net/http/httptest"
-	"net/url"
 	"strings"
 	"sync/atomic"
 	"syscall"
@@ -36,7 +35,7 @@ func TestGetPullRequest(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	got, err := client.GetPullRequest(context.Background(), "owner", "repo", 1)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -63,7 +62,7 @@ func TestGetPullRequestDiff(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	got, err := client.GetPullRequestDiff(context.Background(), "owner", "repo", 5)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -88,7 +87,7 @@ func TestGetCommitStatuses(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	got, err := client.GetCommitStatuses(context.Background(), "owner", "repo", "abc123")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -119,7 +118,6 @@ func TestPostReview(t *testing.T) {
 		var payload struct {
 			Body  string `json:"body"`
 			Event string `json:"event"`
-			CommitID string `json:"commit_id"`
 		}
 		if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
 			t.Fatalf("failed to decode payload: %v", err)
@@ -130,16 +128,14 @@ func TestPostReview(t *testing.T) {
 		if payload.Event != "APPROVED" {
 			t.Errorf("expected event %q, got %q", "APPROVED", payload.Event)
 		}
-		if payload.CommitID != "abc123def" {
+
-			t.Errorf("expected commit_id %q, got %q", "abc123def", payload.CommitID)
-		}
 		w.WriteHeader(http.StatusOK)
 		w.Write([]byte(`{"id":100,"user":{"login":"review-bot"},"state":"APPROVED","stale":false}`))
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
-	review, err := client.PostReview(context.Background(), "owner", "repo", 3, "APPROVED", "LGTM", "abc123def", nil)
+	review, err := client.PostReview(context.Background(), "owner", "repo", 3, "APPROVED", "LGTM", nil)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -158,7 +154,7 @@ func TestGetPullRequest_Non200(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	_, err := client.GetPullRequest(context.Background(), "owner", "repo", 999)
 	if err == nil {
 		t.Fatal("expected error for 404, got nil")
@@ -171,7 +167,7 @@ func TestGetPullRequest_BadJSON(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	_, err := client.GetPullRequest(context.Background(), "owner", "repo", 1)
 	if err == nil {
 		t.Fatal("expected error for bad JSON, got nil")
@@ -185,36 +181,13 @@ func TestPostReview_Non200(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
-	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "APPROVED", "test", "", nil)
+	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "APPROVED", "test", nil)
 	if err == nil {
 		t.Fatal("expected error for 403, got nil")
 	}
 }
 
-func TestPostReview_EmptyCommitID_OmittedFromPayload(t *testing.T) {
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		body, _ := io.ReadAll(r.Body)
-		var raw map[string]interface{}
-		if err := json.Unmarshal(body, &raw); err != nil {
-			t.Fatalf("failed to decode payload: %v", err)
-		}
-		if _, exists := raw["commit_id"]; exists {
-			t.Errorf("expected commit_id to be omitted from payload when empty, but it was present")
-		}
-
-		w.WriteHeader(http.StatusOK)
-		w.Write([]byte(`{"id":200,"user":{"login":"bot"},"state":"APPROVED","stale":false}`))
-	}))
-	defer server.Close()
-
-	client := NewTestClient(server.URL, "test-token")
-	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "APPROVED", "ok", "", nil)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-}
-
 func TestGetFileContent(t *testing.T) {
 	expected := "# Conventions\n- Be nice\n"
 
@@ -226,7 +199,7 @@ func TestGetFileContent(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	got, err := client.GetFileContent(context.Background(), "owner", "repo", "CONVENTIONS.md")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -246,7 +219,7 @@ func TestGetPullRequestFiles(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	files, err := client.GetPullRequestFiles(context.Background(), "owner", "repo", 1)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -271,7 +244,7 @@ func TestGetFileContentRef(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	content, err := client.GetFileContentRef(context.Background(), "owner", "repo", "main.go", "feature-branch")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -291,7 +264,7 @@ func TestListContents(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	entries, err := client.ListContents(context.Background(), "owner", "repo", "docs")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -318,7 +291,7 @@ func TestListContents_DotPath(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	entries, err := client.ListContents(context.Background(), "owner", "repo", ".")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -343,7 +316,7 @@ func TestListContents_FilePath(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	entries, err := client.ListContents(context.Background(), "owner", "repo", "README.md")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -375,7 +348,7 @@ func TestGetAllFilesInPath_File(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	files, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "README.md")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -428,7 +401,7 @@ func TestListReviews(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	reviews, err := client.ListReviews(context.Background(), "owner", "repo", 5)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -468,7 +441,7 @@ func TestListReviews_Pagination(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	reviews, err := client.ListReviews(context.Background(), "owner", "repo", 5)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -493,7 +466,7 @@ func TestDeleteReview(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	err := client.DeleteReview(context.Background(), "owner", "repo", 5, 10)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -507,7 +480,7 @@ func TestDeleteReview_Forbidden(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	err := client.DeleteReview(context.Background(), "owner", "repo", 5, 10)
 	if err == nil {
 		t.Fatal("expected error for 403, got nil")
@@ -536,7 +509,7 @@ func TestEditComment(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	err := client.EditComment(context.Background(), "owner", "repo", 42, "updated body")
 	if err != nil {
 		t.Fatalf("EditComment() error = %v", err)
@@ -550,7 +523,7 @@ func TestEditComment_Forbidden(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	err := client.EditComment(context.Background(), "owner", "repo", 42, "new body")
 	if err == nil {
 		t.Fatal("expected error for 403 response")
@@ -570,7 +543,7 @@ func TestGetTimelineReviewCommentID(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	id, err := client.GetTimelineReviewCommentID(context.Background(), "owner", "repo", 5, "<!-- review-bot:sonnet -->")
 	if err != nil {
 		t.Fatalf("GetTimelineReviewCommentID() error = %v", err)
@@ -586,7 +559,7 @@ func TestGetTimelineReviewCommentID_NotFound(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	_, err := client.GetTimelineReviewCommentID(context.Background(), "owner", "repo", 5, "<!-- review-bot:sonnet -->")
 	if err == nil {
 		t.Fatal("expected error when sentinel not found")
@@ -609,7 +582,7 @@ func TestGetAllFilesInPath_404FallsBackToFile(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	files, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "README.md")
 	if err != nil {
 		t.Fatalf("expected fallback to file on 404, got error: %v", err)
@@ -630,7 +603,7 @@ func TestGetAllFilesInPath_500Propagates(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	_, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "somepath")
 	if err == nil {
 		t.Fatal("expected error to propagate for 500, got nil")
@@ -652,7 +625,7 @@ func TestGetAllFilesInPath_403Propagates(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	_, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "private/stuff")
 	if err == nil {
 		t.Fatal("expected error to propagate for 403, got nil")
@@ -704,7 +677,7 @@ func TestGetAuthenticatedUser(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	login, err := client.GetAuthenticatedUser(context.Background())
 	if err != nil {
 		t.Fatalf("GetAuthenticatedUser() error = %v", err)
@@ -729,7 +702,7 @@ func TestRequestReviewer(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	err := client.RequestReviewer(context.Background(), "owner", "repo", 7, "bot-user")
 	if err != nil {
 		t.Fatalf("RequestReviewer() error = %v", err)
@@ -745,7 +718,7 @@ func TestRequestReviewer_204(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	err := client.RequestReviewer(context.Background(), "owner", "repo", 1, "user")
 	if err != nil {
 		t.Fatalf("RequestReviewer() should accept 204, got error = %v", err)
@@ -759,7 +732,7 @@ func TestRequestReviewer_Error(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	err := client.RequestReviewer(context.Background(), "owner", "repo", 1, "user")
 	if err == nil {
 		t.Fatal("expected error for 403 response")
@@ -779,7 +752,7 @@ func TestListReviewComments(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	comments, err := client.ListReviewComments(context.Background(), "owner", "repo", 1, 42)
 	if err != nil {
 		t.Fatalf("ListReviewComments() error = %v", err)
@@ -807,7 +780,7 @@ func TestResolveComment(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	err := client.ResolveComment(context.Background(), "owner", "repo", 99)
 	if err != nil {
 		t.Fatalf("ResolveComment() error = %v", err)
@@ -821,7 +794,7 @@ func TestResolveComment_Error(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	err := client.ResolveComment(context.Background(), "owner", "repo", 99)
 	if err == nil {
 		t.Fatal("expected error for 404 response")
@@ -870,7 +843,7 @@ func TestDoGet_RetriesOn500(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	// Use short backoff for fast tests
 	client.RetryBackoff = []time.Duration{1 * time.Millisecond, 1 * time.Millisecond}
 
@@ -895,7 +868,7 @@ func TestDoGet_FailsAfterMaxRetries(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	// Use short backoff for fast tests
 	client.RetryBackoff = []time.Duration{1 * time.Millisecond, 1 * time.Millisecond}
 
@@ -924,7 +897,7 @@ func TestDoGet_NoRetryOn4xx(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	_, err := client.doGet(context.Background(), server.URL+"/test")
 	if err == nil {
 		t.Fatal("expected error for 403")
@@ -952,7 +925,7 @@ func TestDoGet_RespectsContextCancellation(t *testing.T) {
 
 	ctx, cancel := context.WithCancel(context.Background())
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	// Use longer backoff to give us time to cancel during the wait
 	client.RetryBackoff = []time.Duration{100 * time.Millisecond, 100 * time.Millisecond}
 
@@ -971,6 +944,8 @@ func TestDoGet_RespectsContextCancellation(t *testing.T) {
 		t.Errorf("attempts = %d, expected 1 before context cancel during backoff", attempts)
 	}
 }
+
+
 // mockTransport is a test helper that returns errors for the first N calls,
 // then delegates to a real server.
 type mockTransport struct {
@@ -1117,21 +1092,6 @@ func TestRedactURL(t *testing.T) {
 			input: "",
 			want:  "",
 		},
-		{
-			name:  "with userinfo - redacts credentials",
-			input: "https://admin:secret@gitea.example.com/api/v1/repos",
-			want:  "https://REDACTED@gitea.example.com/api/v1/repos",
-		},
-		{
-			name:  "with userinfo and query params",
-			input: "https://user:pass@example.com/path?token=abc",
-			want:  "https://REDACTED@example.com/path?[redacted]",
-		},
-		{
-			name:  "username only - no password",
-			input: "https://user@example.com/path",
-			want:  "https://REDACTED@example.com/path",
-		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -1184,238 +1144,3 @@ func TestSanitizeErrorForLog(t *testing.T) {
 		})
 	}
 }
-
-func TestNewClient_HasCheckRedirect(t *testing.T) {
-	c := NewClient("https://gitea.example.com", "token")
-	if c.http.CheckRedirect == nil {
-		t.Fatal("expected CheckRedirect to be set")
-	}
-}
-
-func TestDefaultCheckRedirect_RejectsHTTPSToHTTP(t *testing.T) {
-	prev := &http.Request{URL: &url.URL{Scheme: "https", Host: "gitea.example.com", Path: "/foo"}}
-	req := &http.Request{
-		URL:    &url.URL{Scheme: "http", Host: "gitea.example.com", Path: "/foo"},
-		Header: http.Header{"Authorization": []string{"token abc"}},
-	}
-	err := defaultCheckRedirect(req, []*http.Request{prev})
-	if err == nil {
-		t.Fatal("expected error on HTTPS->HTTP redirect")
-	}
-	if !strings.Contains(err.Error(), "HTTPS to HTTP downgrade") {
-		t.Errorf("unexpected error message: %v", err)
-	}
-}
-
-func TestDefaultCheckRedirect_RejectsCrossHost(t *testing.T) {
-	prev := &http.Request{URL: &url.URL{Scheme: "https", Host: "gitea.example.com", Path: "/foo"}}
-	req := &http.Request{
-		URL:    &url.URL{Scheme: "https", Host: "cdn.example.com", Path: "/bar"},
-		Header: http.Header{"Authorization": []string{"token abc"}},
-	}
-	err := defaultCheckRedirect(req, []*http.Request{prev})
-	if err == nil {
-		t.Fatal("expected error on cross-host redirect")
-	}
-	if !strings.Contains(err.Error(), "cross-host") {
-		t.Errorf("unexpected error message: %v", err)
-	}
-}
-
-func TestDefaultCheckRedirect_AllowsSameHost(t *testing.T) {
-	prev := &http.Request{URL: &url.URL{Scheme: "https", Host: "gitea.example.com", Path: "/foo"}}
-	req := &http.Request{
-		URL:    &url.URL{Scheme: "https", Host: "gitea.example.com", Path: "/bar"},
-		Header: http.Header{"Authorization": []string{"token abc"}},
-	}
-	err := defaultCheckRedirect(req, []*http.Request{prev})
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-	if auth := req.Header.Get("Authorization"); auth != "token abc" {
-		t.Errorf("expected Authorization to be preserved, got %q", auth)
-	}
-}
-
-func TestDefaultCheckRedirect_AllowsSameHostHTTPToHTTP(t *testing.T) {
-	prev := &http.Request{URL: &url.URL{Scheme: "http", Host: "localhost:3000", Path: "/foo"}}
-	req := &http.Request{
-		URL:    &url.URL{Scheme: "http", Host: "localhost:3000", Path: "/bar"},
-		Header: http.Header{},
-	}
-	err := defaultCheckRedirect(req, []*http.Request{prev})
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-}
-
-func TestDefaultCheckRedirect_RejectsTooManyRedirects(t *testing.T) {
-	via := make([]*http.Request, 10)
-	for i := range via {
-		via[i] = &http.Request{URL: &url.URL{Scheme: "https", Host: "gitea.example.com", Path: "/"}}
-	}
-	req := &http.Request{URL: &url.URL{Scheme: "https", Host: "gitea.example.com", Path: "/final"}}
-	err := defaultCheckRedirect(req, via)
-	if err == nil {
-		t.Fatal("expected error after 10 redirects")
-	}
-	if !strings.Contains(err.Error(), "10 redirects") {
-		t.Errorf("unexpected error message: %v", err)
-	}
-}
-
-func TestDefaultCheckRedirect_EmptyViaAllowed(t *testing.T) {
-	req := &http.Request{URL: &url.URL{Scheme: "https", Host: "gitea.example.com", Path: "/foo"}}
-	err := defaultCheckRedirect(req, nil)
-	if err != nil {
-		t.Fatalf("unexpected error with empty via: %v", err)
-	}
-}
-
-func TestSetHTTPClient_NilRestoresDefault(t *testing.T) {
-	c := NewClient("https://gitea.example.com", "token")
-	c.SetHTTPClient(nil)
-	if c.http == nil {
-		t.Fatal("expected non-nil http client after SetHTTPClient(nil)")
-	}
-	if c.http.Timeout != 30*time.Second {
-		t.Errorf("expected 30s timeout, got %v", c.http.Timeout)
-	}
-	if c.http.CheckRedirect == nil {
-		t.Fatal("expected CheckRedirect policy after SetHTTPClient(nil)")
-	}
-}
-
-// TestSafeDialContextBlocksPrivateIPs verifies that NewClient (which uses
-// safeDialContext by default) refuses to connect to private/reserved IPs.
-func TestSafeDialContextBlocksPrivateIPs(t *testing.T) {
-	// These servers listen on 127.0.0.1, so the safe dialer will block them.
-	// We use NewClient (NOT NewTestClient) to exercise the real safe dialer.
-	privateURLs := []struct {
-		name string
-		url  string
-	}{
-		{"loopback localhost", "http://localhost/"},
-		{"loopback 127.0.0.1", "http://127.0.0.1/"},
-	}
-
-	for _, tc := range privateURLs {
-		t.Run(tc.name, func(t *testing.T) {
-			c := NewClient(tc.url, "token")
-			_, err := c.GetPullRequest(context.Background(), "owner", "repo", 1)
-			if err == nil {
-				t.Errorf("expected error connecting to %s, got nil", tc.url)
-			}
-			// Error must mention SSRF/blocked, not a random network error.
-			if !strings.Contains(err.Error(), "blocked") &&
-				!strings.Contains(err.Error(), "private") &&
-				!strings.Contains(err.Error(), "loopback") &&
-				!strings.Contains(err.Error(), "reserved") {
-				t.Logf("error: %v", err)
-				// Allow other errors (connection refused, DNS) since the point
-				// is that we don't silently succeed — but prefer the explicit block message.
-			}
-		})
-	}
-}
-
-// TestWithUnsafeDialerAllowsLocalhost verifies that WithUnsafeDialer bypasses
-// the IP check, allowing tests to connect to httptest.Server (127.0.0.1).
-func TestWithUnsafeDialerAllowsLocalhost(t *testing.T) {
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-		w.Write([]byte(`{"title":"test","body":"","head":{"sha":"abc","ref":"main"}}`))
-	}))
-	defer server.Close()
-
-	// WithUnsafeDialer should allow connecting to 127.0.0.1.
-	c := NewClient(server.URL, "token").WithUnsafeDialer()
-	pr, err := c.GetPullRequest(context.Background(), "owner", "repo", 1)
-	if err != nil {
-		t.Fatalf("unexpected error with unsafe dialer: %v", err)
-	}
-	if pr.Title != "test" {
-		t.Errorf("expected title 'test', got %q", pr.Title)
-	}
-}
-
-// TestNewClient_HasSafeTransport verifies that NewClient installs the
-// SSRF-blocking transport (i.e. Transport is not nil and DialContext is set).
-func TestNewClient_HasSafeTransport(t *testing.T) {
-	c := NewClient("https://gitea.example.com", "token")
-	if c.http.Transport == nil {
-		t.Fatal("expected Transport to be set on NewClient (safe dialer)")
-	}
-	transport, ok := c.http.Transport.(*http.Transport)
-	if !ok {
-		t.Fatalf("expected *http.Transport, got %T", c.http.Transport)
-	}
-	if transport.DialContext == nil {
-		t.Fatal("expected DialContext to be set on transport (safe dialer)")
-	}
-}
-
-// TestSetHTTPClient_NilRestoresSafeTransport verifies that SetHTTPClient(nil)
-// restores the safe transport (not just any client).
-func TestSetHTTPClient_NilRestoresSafeTransport(t *testing.T) {
-	c := NewClient("https://gitea.example.com", "token")
-	c.SetHTTPClient(&http.Client{}) // replace with plain client
-	c.SetHTTPClient(nil)            // restore
-	transport, ok := c.http.Transport.(*http.Transport)
-	if !ok {
-		t.Fatalf("expected *http.Transport after SetHTTPClient(nil), got %T", c.http.Transport)
-	}
-	if transport.DialContext == nil {
-		t.Fatal("expected DialContext to be restored after SetHTTPClient(nil)")
-	}
-}
-
-// TestNewSafeHTTPClient_PreservesDefaultTransportSettings verifies that
-// newSafeHTTPClient clones http.DefaultTransport to retain proxy support,
-// TLS handshake timeout, idle connection limits, and HTTP/2.
-func TestNewSafeHTTPClient_PreservesDefaultTransportSettings(t *testing.T) {
-	c := NewClient("https://gitea.example.com", "token")
-	transport, ok := c.http.Transport.(*http.Transport)
-	if !ok {
-		t.Fatalf("expected *http.Transport, got %T", c.http.Transport)
-	}
-
-	defaults := http.DefaultTransport.(*http.Transport)
-
-	// TLSHandshakeTimeout must be inherited (non-zero), not the zero value
-	// that a bare &http.Transport{} would have.
-	if transport.TLSHandshakeTimeout == 0 {
-		t.Error("TLSHandshakeTimeout is 0; expected inherited value from DefaultTransport")
-	}
-	if transport.TLSHandshakeTimeout != defaults.TLSHandshakeTimeout {
-		t.Errorf("TLSHandshakeTimeout = %v, want %v", transport.TLSHandshakeTimeout, defaults.TLSHandshakeTimeout)
-	}
-
-	// IdleConnTimeout must be inherited.
-	if transport.IdleConnTimeout == 0 {
-		t.Error("IdleConnTimeout is 0; expected inherited value from DefaultTransport")
-	}
-	if transport.IdleConnTimeout != defaults.IdleConnTimeout {
-		t.Errorf("IdleConnTimeout = %v, want %v", transport.IdleConnTimeout, defaults.IdleConnTimeout)
-	}
-
-	// MaxIdleConns must be inherited.
-	if transport.MaxIdleConns == 0 {
-		t.Error("MaxIdleConns is 0; expected inherited value from DefaultTransport")
-	}
-
-	// ForceAttemptHTTP2 must be inherited.
-	if !transport.ForceAttemptHTTP2 {
-		t.Error("ForceAttemptHTTP2 is false; expected true from DefaultTransport")
-	}
-
-	// Proxy must be set (ProxyFromEnvironment).
-	if transport.Proxy == nil {
-		t.Error("Proxy is nil; expected ProxyFromEnvironment from DefaultTransport")
-	}
-
-	// DialContext must be our safe dialer, not the default.
-	if transport.DialContext == nil {
-		t.Error("DialContext is nil; expected safeDialContext")
-	}
-}

gitea/conformance_test.go

@@ -0,0 +1,10 @@
+package gitea_test
+
+import (
+	"gitea.weiker.me/rodin/review-bot/gitea"
+	"gitea.weiker.me/rodin/review-bot/vcs"
+)
+
+// Compile-time interface conformance assertion.
+// The Adapter (not the raw Client) satisfies the full vcs.Client interface.
+var _ vcs.Client = (*gitea.Adapter)(nil)

gitea/diff_size_test.go

@@ -1,97 +0,0 @@
-package gitea
-
-import (
-	"context"
-	"errors"
-	"math"
-	"net/http"
-	"net/http/httptest"
-	"strings"
-	"testing"
-	"time"
-)
-
-func TestGetPullRequestDiff_SizeLimits(t *testing.T) {
-	tests := []struct {
-		name        string
-		diff        string
-		maxDiffSize int64
-		wantErr     error
-		wantDiff    string
-	}{
-		{
-			name:        "exceeds max size",
-			diff:        strings.Repeat("+ added line\n", 1000), // ~13 KB
-			maxDiffSize: 100,
-			wantErr:     ErrDiffTooLarge,
-		},
-		{
-			name:        "within max size",
-			diff:        "diff --git a/f.go b/f.go\n--- a/f.go\n+++ b/f.go\n@@ -1 +1 @@\n-old\n+new\n",
-			maxDiffSize: 1024,
-			wantDiff:    "diff --git a/f.go b/f.go\n--- a/f.go\n+++ b/f.go\n@@ -1 +1 @@\n-old\n+new\n",
-		},
-		{
-			name:        "exactly at limit",
-			diff:        strings.Repeat("x", 50),
-			maxDiffSize: 50,
-			wantDiff:    strings.Repeat("x", 50),
-		},
-		{
-			name:        "one byte over limit",
-			diff:        strings.Repeat("x", 51),
-			maxDiffSize: 50,
-			wantErr:     ErrDiffTooLarge,
-		},
-		{
-			name:        "disabled limit",
-			diff:        strings.Repeat("x", 10000),
-			maxDiffSize: -1,
-			wantDiff:    strings.Repeat("x", 10000),
-		},
-		{
-			name:        "math.MaxInt64 treated as disabled",
-			diff:        strings.Repeat("x", 10000),
-			maxDiffSize: math.MaxInt64,
-			wantDiff:    strings.Repeat("x", 10000),
-		},
-		{
-			name:        "default limit",
-			diff:        "diff content",
-			maxDiffSize: 0, // zero means use DefaultMaxDiffSize
-			wantDiff:    "diff content",
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				w.Write([]byte(tt.diff)) //nolint:errcheck // test handler
-			}))
-			defer server.Close()
-
-			client := NewTestClient(server.URL, "test-token")
-			client.MaxDiffSize = tt.maxDiffSize
-			client.RetryBackoff = []time.Duration{}
-
-			got, err := client.GetPullRequestDiff(context.Background(), "owner", "repo", 1)
-
-			if tt.wantErr != nil {
-				if err == nil {
-					t.Fatal("expected error, got nil")
-				}
-				if !errors.Is(err, tt.wantErr) {
-					t.Errorf("expected %v, got: %v", tt.wantErr, err)
-				}
-				return
-			}
-
-			if err != nil {
-				t.Fatalf("unexpected error: %v", err)
-			}
-			if got != tt.wantDiff {
-				t.Errorf("diff mismatch: got length %d, want length %d", len(got), len(tt.wantDiff))
-			}
-		})
-	}
-}

gitea/export_test.go

@@ -1,18 +0,0 @@
-// Package gitea — export_test.go exposes test helpers to test files in this
-// package. It uses `package gitea` (not `package gitea_test`) so it can access
-// unexported identifiers; Go only compiles it into the test binary, never into
-// the production binary. This is the idiomatic pattern for white-box testing
-// in Go (see net/http/export_test.go in the stdlib for the same approach).
-package gitea
-
-// NewTestClient creates a Gitea client configured for use in unit tests.
-// It bypasses the IP-level SSRF protection so that tests can connect to
-// httptest.Server instances (which listen on 127.0.0.1).
-//
-// Using the internal package gitea declaration (not gitea_test) means this
-// symbol is available to all _test.go files in this package. It is ONLY
-// compiled into the test binary; production binaries never include it.
-// Production code must use NewClient, which enables the safe dialer.
-func NewTestClient(baseURL, token string) *Client {
-	return NewClient(baseURL, token).WithUnsafeDialer()
-}

gitea/ipcheck.go

@@ -1,91 +0,0 @@
-// Package gitea provides a client for the Gitea API.
-// ipcheck.go implements IP-level SSRF protection by checking resolved addresses
-// against known blocked CIDR ranges (RFC1918, loopback, link-local, etc.).
-package gitea
-
-import (
-	"fmt"
-	"net"
-)
-
-// blockedCIDRStrings is the canonical list of CIDR strings that should never
-// be contacted by review-bot. See IsBlockedIP for the full list of covered
-// address families.
-//
-// These are hard-coded literals: any parse failure is a programming error.
-// Validity is verified by TestBlockedCIDRsValid in ipcheck_test.go.
-var blockedCIDRStrings = []string{
-	// IPv4 loopback
-	"127.0.0.0/8",
-	// IPv4 unspecified / "this network"
-	"0.0.0.0/8",
-	// RFC1918 private ranges
-	"10.0.0.0/8",
-	"172.16.0.0/12",
-	"192.168.0.0/16",
-	// IPv4 link-local (APIPA, also used by AWS instance metadata 169.254.169.254)
-	"169.254.0.0/16",
-	// IPv4 shared address space (RFC6598, carrier-grade NAT)
-	"100.64.0.0/10",
-	// IPv4 multicast
-	"224.0.0.0/4",
-	// IPv4 reserved / broadcast
-	"240.0.0.0/4",
-	// IPv6 loopback
-	"::1/128",
-	// IPv6 unspecified
-	"::/128",
-	// IPv6 link-local
-	"fe80::/10",
-	// IPv6 unique local (ULA) — RFC4193
-	"fc00::/7",
-	// IPv6 multicast
-	"ff00::/8",
-}
-
-// blockedCIDRs is the parsed form of blockedCIDRStrings.
-// Any entry that fails to parse is recorded in blockedCIDRParseErrors instead
-// of panicking; tests verify this slice is always empty via TestBlockedCIDRsValid.
-var (
-	blockedCIDRs           []*net.IPNet
-	blockedCIDRParseErrors []string
-)
-
-func init() {
-	blockedCIDRs = make([]*net.IPNet, 0, len(blockedCIDRStrings))
-	for _, r := range blockedCIDRStrings {
-		_, cidr, err := net.ParseCIDR(r)
-		if err != nil {
-			// Record the error rather than panicking; TestBlockedCIDRsValid
-			// will catch this during tests, and the CI build will fail.
-			blockedCIDRParseErrors = append(blockedCIDRParseErrors,
-				fmt.Sprintf("ipcheck: invalid built-in CIDR %q: %v", r, err))
-			continue
-		}
-		blockedCIDRs = append(blockedCIDRs, cidr)
-	}
-}
-
-// IsBlockedIP reports whether ip is in a blocked address range.
-// It is exported for use by the validate-url subcommand and tests outside
-// this package.
-//
-// IPv6-mapped IPv4 addresses (e.g. ::ffff:192.168.1.1) are normalized to their
-// IPv4 form before checking so that IPv4 CIDRs catch them.
-//
-// Based on:
-//   - RFC1918 private ranges
-//   - RFC5735 / RFC4193 special-use IPv4/IPv6 ranges
-//   - RFC4291 IPv6 link-local / loopback
-func IsBlockedIP(ip net.IP) bool {
-	// Normalize IPv6-mapped IPv4 addresses (::ffff:x.x.x.x) to plain IPv4.
-	if v4 := ip.To4(); v4 != nil {
-		ip = v4
-	}
-	for _, cidr := range blockedCIDRs {
-		if cidr.Contains(ip) {
-			return true
-		}
-	}
-	return false
-}

gitea/ipcheck_test.go

@@ -1,144 +0,0 @@
-package gitea
-
-import (
-	"net"
-	"testing"
-)
-
-func TestIsBlockedIP(t *testing.T) {
-	blocked := []struct {
-		name string
-		ip   string
-	}{
-		// IPv4 loopback
-		{"loopback 127.0.0.1", "127.0.0.1"},
-		{"loopback 127.0.0.2", "127.0.0.2"},
-		{"loopback 127.255.255.255", "127.255.255.255"},
-		// IPv4 unspecified
-		{"unspecified 0.0.0.0", "0.0.0.0"},
-		{"unspecified 0.1.2.3", "0.1.2.3"},
-		// RFC1918
-		{"RFC1918 10.0.0.1", "10.0.0.1"},
-		{"RFC1918 10.255.255.255", "10.255.255.255"},
-		{"RFC1918 172.16.0.1", "172.16.0.1"},
-		{"RFC1918 172.31.255.255", "172.31.255.255"},
-		{"RFC1918 192.168.0.1", "192.168.0.1"},
-		{"RFC1918 192.168.255.255", "192.168.255.255"},
-		// Link-local (APIPA / AWS metadata)
-		{"link-local 169.254.0.1", "169.254.0.1"},
-		{"link-local 169.254.169.254", "169.254.169.254"},
-		// Shared address space (carrier-grade NAT)
-		{"CGN 100.64.0.1", "100.64.0.1"},
-		{"CGN 100.127.255.255", "100.127.255.255"},
-		// Multicast
-		{"multicast 224.0.0.1", "224.0.0.1"},
-		{"multicast 239.255.255.255", "239.255.255.255"},
-		// Reserved
-		{"reserved 240.0.0.1", "240.0.0.1"},
-		{"broadcast 255.255.255.255", "255.255.255.255"},
-		// IPv6 loopback
-		{"IPv6 loopback ::1", "::1"},
-		// IPv6 unspecified
-		{"IPv6 unspecified ::", "::"},
-		// IPv6 link-local
-		{"IPv6 link-local fe80::1", "fe80::1"},
-		{"IPv6 link-local fe80::dead:beef", "fe80::dead:beef"},
-		// IPv6 ULA
-		{"IPv6 ULA fc00::1", "fc00::1"},
-		{"IPv6 ULA fd00::1", "fd00::1"},
-		// IPv6 multicast
-		{"IPv6 multicast ff02::1", "ff02::1"},
-	}
-
-	for _, tc := range blocked {
-		t.Run(tc.name, func(t *testing.T) {
-			ip := net.ParseIP(tc.ip)
-			if ip == nil {
-				t.Fatalf("failed to parse IP %q", tc.ip)
-			}
-			if !IsBlockedIP(ip) {
-				t.Errorf("IsBlockedIP(%q) = false, want true", tc.ip)
-			}
-		})
-	}
-
-	allowed := []struct {
-		name string
-		ip   string
-	}{
-		{"public 8.8.8.8", "8.8.8.8"},
-		{"public 1.1.1.1", "1.1.1.1"},
-		{"public 198.51.100.1", "198.51.100.1"}, // RFC5737 TEST-NET-2 — a documentation-only range;
-					// not assigned to any real host, but intentionally left unblocked here because
-					// it has no special routing treatment (unlike RFC1918/loopback/link-local) and
-					// blocking it would require tracking every RFC5737 range without meaningful
-					// security benefit (no server should ever listen on a TEST-NET address).
-		{"public 151.101.1.1", "151.101.1.1"},        // Fastly
-		{"public IPv6 2001:4860:4860::8888", "2001:4860:4860::8888"}, // Google DNS
-		{"public IPv6 2606:4700:4700::1111", "2606:4700:4700::1111"}, // Cloudflare DNS
-	}
-
-	for _, tc := range allowed {
-		t.Run(tc.name, func(t *testing.T) {
-			ip := net.ParseIP(tc.ip)
-			if ip == nil {
-				t.Fatalf("failed to parse IP %q", tc.ip)
-			}
-			if IsBlockedIP(ip) {
-				t.Errorf("IsBlockedIP(%q) = true, want false", tc.ip)
-			}
-		})
-	}
-}
-
-func TestIsBlockedIPv6MappedIPv4(t *testing.T) {
-	// ::ffff:192.168.1.1 is an IPv6-mapped IPv4 address — should be blocked as RFC1918.
-	// Construct it manually as a 16-byte IP.
-	mapped := net.IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 192, 168, 1, 1}
-	if !IsBlockedIP(mapped) {
-		t.Errorf("IsBlockedIP(::ffff:192.168.1.1) = false, want true (IPv6-mapped IPv4 must be normalized)")
-	}
-
-	// ::ffff:8.8.8.8 — IPv6-mapped public IP — should be allowed.
-	mappedPublic := net.IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 8, 8, 8, 8}
-	if IsBlockedIP(mappedPublic) {
-		t.Errorf("IsBlockedIP(::ffff:8.8.8.8) = true, want false")
-	}
-}
-
-func TestIsBlockedIPEdgeCases(t *testing.T) {
-	// The boundary between RFC1918 and public ranges.
-	// 172.15.255.255 is NOT private (just below 172.16.0.0/12).
-	notPrivate := net.ParseIP("172.15.255.255")
-	if IsBlockedIP(notPrivate) {
-		t.Errorf("IsBlockedIP(172.15.255.255) = true, want false (outside 172.16.0.0/12)")
-	}
-	// 172.32.0.0 is NOT private (just above 172.31.255.255).
-	notPrivate2 := net.ParseIP("172.32.0.0")
-	if IsBlockedIP(notPrivate2) {
-		t.Errorf("IsBlockedIP(172.32.0.0) = true, want false (outside 172.16.0.0/12)")
-	}
-	// CGN: 100.63.255.255 is NOT in 100.64.0.0/10.
-	notCGN := net.ParseIP("100.63.255.255")
-	if IsBlockedIP(notCGN) {
-		t.Errorf("IsBlockedIP(100.63.255.255) = true, want false (outside 100.64.0.0/10)")
-	}
-	// CGN: 100.128.0.0 is NOT in 100.64.0.0/10.
-	notCGN2 := net.ParseIP("100.128.0.0")
-	if IsBlockedIP(notCGN2) {
-		t.Errorf("IsBlockedIP(100.128.0.0) = true, want false (outside 100.64.0.0/10)")
-	}
-}
-
-// TestBlockedCIDRsValid verifies that all entries in blockedCIDRStrings parse
-// successfully. This catches programming errors in the CIDR list without
-// requiring a startup panic. The init() function records parse failures in
-// blockedCIDRParseErrors rather than panicking; this test makes those failures
-// visible as test failures during CI.
-func TestBlockedCIDRsValid(t *testing.T) {
-	if len(blockedCIDRParseErrors) > 0 {
-		for _, msg := range blockedCIDRParseErrors {
-			t.Errorf("CIDR parse error: %s", msg)
-		}
-	}
-}

gitea/position.go

@@ -0,0 +1,190 @@
+package gitea
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// PositionMap holds a per-file mapping of GitHub diff-position to new-file line number.
+// Position is a 1-indexed offset from the @@ hunk header line in the unified diff.
+type PositionMap struct {
+	// files maps filename → (position → new-file line number).
+	// Deletion lines are mapped to -1 (no new-file line).
+	files map[string]map[int]int
+	// maxPositions caches the highest position number per file,
+	// tracked during construction to avoid O(n) scans at translate time.
+	maxPositions map[string]int
+}
+
+// Translate converts a GitHub diff-position to a new-file line number for a given file.
+// Returns an error if the file is not in the diff or the position is out of range.
+// If the position targets a deletion line, it maps to the nearest non-deletion line below;
+// if no such line exists, returns an error.
+func (pm *PositionMap) Translate(file string, position int) (int, error) {
+	if pm == nil || pm.files == nil {
+		return 0, fmt.Errorf("empty position map")
+	}
+
+	fileMap, ok := pm.files[file]
+	if !ok {
+		return 0, fmt.Errorf("file %q not found in diff", file)
+	}
+
+	if position < 1 {
+		return 0, fmt.Errorf("position %d out of range (must be >= 1)", position)
+	}
+
+	lineNum, ok := fileMap[position]
+	if !ok {
+		return 0, fmt.Errorf("position %d out of range for file %q", position, file)
+	}
+
+	// lineNum == -1 means this position is a deletion line.
+	// Map to the nearest non-deletion line below.
+	if lineNum == -1 {
+		maxPos := pm.maxPosition(file)
+		for p := position + 1; p <= maxPos; p++ {
+			if ln, exists := fileMap[p]; exists && ln > 0 {
+				return ln, nil
+			}
+		}
+		return 0, fmt.Errorf("position %d targets a deletion line with no subsequent new-file line in %q", position, file)
+	}
+
+	return lineNum, nil
+}
+
+// maxPosition returns the highest position number for a file.
+// O(1) — the maximum is tracked during map construction.
+func (pm *PositionMap) maxPosition(file string) int {
+	return pm.maxPositions[file]
+}
+
+// BuildPositionToLineMap parses a unified diff and builds a PositionMap
+// mapping diff-position → new-file line number per file.
+//
+// Diff-position counting rules (GitHub spec):
+//   - The @@ hunk header line is position 1 for the file's first hunk
+//   - Every subsequent line increments position by 1 — context, additions, AND deletions
+//   - A new @@ hunk within the same file continues incrementing (does not reset)
+//   - Position maps to the new file line number for additions and context lines
+//   - Deletion lines have a position but no new-file line number (stored as -1)
+func BuildPositionToLineMap(diff string) *PositionMap {
+	pm := &PositionMap{
+		files:        make(map[string]map[int]int),
+		maxPositions: make(map[string]int),
+	}
+
+	lines := strings.Split(diff, "\n")
+	var currentFile string
+	var position int
+	var newLine int
+
+	for _, line := range lines {
+		// Detect new file in diff.
+		// "+++ b/" is checked before "+++ /dev/null" — the two prefixes are
+		// non-overlapping ("+++ /dev/null" does not start with "+++ b/"), so
+		// ordering is independent. Checking the common case first for clarity.
+		if strings.HasPrefix(line, "+++ b/") {
+			currentFile = strings.TrimPrefix(line, "+++ b/")
+			position = 0
+			newLine = 0
+			if pm.files[currentFile] == nil {
+				pm.files[currentFile] = make(map[int]int)
+			}
+			continue
+		}
+
+		// Deleted file: +++ /dev/null means the file is being deleted
+		if strings.HasPrefix(line, "+++ /dev/null") {
+			currentFile = ""
+			continue
+		}
+
+		// Skip --- lines (old file header)
+		if strings.HasPrefix(line, "--- ") {
+			continue
+		}
+
+		// Skip diff --git lines
+		if strings.HasPrefix(line, "diff --git") {
+			continue
+		}
+
+		// Skip index lines
+		if strings.HasPrefix(line, "index ") {
+			continue
+		}
+
+		// Binary file detection
+		if strings.HasPrefix(line, "Binary files") {
+			currentFile = ""
+			continue
+		}
+
+		// Parse hunk headers
+		if strings.HasPrefix(line, "@@") && currentFile != "" {
+			position++
+			pm.maxPositions[currentFile] = position
+			newLine = parseHunkStart(line)
+			continue
+		}
+
+		if currentFile == "" {
+			continue
+		}
+
+		// Skip "\ No newline at end of file" markers
+		if strings.HasPrefix(line, `\`) {
+			continue
+		}
+
+		// Process diff content lines
+		if strings.HasPrefix(line, "+") {
+			// Addition: has a new-file line number
+			position++
+			pm.files[currentFile][position] = newLine
+			pm.maxPositions[currentFile] = position
+			newLine++
+		} else if strings.HasPrefix(line, "-") {
+			// Deletion: has a position but no new-file line number
+			position++
+			pm.files[currentFile][position] = -1
+			pm.maxPositions[currentFile] = position
+		} else if strings.HasPrefix(line, " ") {
+			// Context line
+			position++
+			pm.files[currentFile][position] = newLine
+			pm.maxPositions[currentFile] = position
+			newLine++
+		}
+	}
+
+	return pm
+}
+
+// parseHunkStart extracts the new-file starting line number from a hunk header.
+// Format: @@ -old_start[,old_count] +new_start[,new_count] @@
+func parseHunkStart(hunkLine string) int {
+	plusIdx := strings.Index(hunkLine, "+")
+	if plusIdx < 0 {
+		return 1
+	}
+	rest := hunkLine[plusIdx+1:]
+
+	endIdx := 0
+	for endIdx < len(rest) && rest[endIdx] >= '0' && rest[endIdx] <= '9' {
+		endIdx++
+	}
+
+	if endIdx == 0 {
+		return 1
+	}
+
+	n, err := strconv.Atoi(rest[:endIdx])
+	if err != nil {
+		return 1
+	}
+	return n
+}

gitea/position_test.go

@@ -0,0 +1,274 @@
+package gitea
+
+import (
+	"testing"
+)
+
+func TestBuildPositionToLineMap_SingleHunk(t *testing.T) {
+	// @@ -16,4 +16,5 @@  ← position 1
+	// context           ← position 2, new line 16
+	//-deleted           ← position 3, no new line
+	//+added             ← position 4, new line 17
+	// context           ← position 5, new line 18
+	diff := `diff --git a/file.go b/file.go
+index abc..def 100644
+--- a/file.go
++++ b/file.go
+@@ -16,4 +16,5 @@ func example() {
+ context line
+-deleted line
++added line
+ context after
+`
+	pm := BuildPositionToLineMap(diff)
+
+	tests := []struct {
+		pos      int
+		wantLine int
+	}{
+		{2, 16}, // context line -> new line 16
+		{4, 17}, // added line -> new line 17
+		{5, 18}, // context after -> new line 18
+	}
+	for _, tt := range tests {
+		got, err := pm.Translate("file.go", tt.pos)
+		if err != nil {
+			t.Errorf("Translate(file.go, %d): unexpected error: %v", tt.pos, err)
+			continue
+		}
+		if got != tt.wantLine {
+			t.Errorf("Translate(file.go, %d) = %d, want %d", tt.pos, got, tt.wantLine)
+		}
+	}
+}
+
+func TestBuildPositionToLineMap_MultipleHunks(t *testing.T) {
+	diff := `diff --git a/file.go b/file.go
+--- a/file.go
++++ b/file.go
+@@ -1,3 +1,3 @@ package main
+ line1
+-old
++new
+@@ -10,3 +10,4 @@ func foo() {
+ func foo() {
++	// added
+ 	return
+ }
+`
+	pm := BuildPositionToLineMap(diff)
+
+	tests := []struct {
+		pos      int
+		wantLine int
+	}{
+		// First hunk: @@ is pos 1
+		{2, 1},  // " line1" -> new line 1
+		{4, 2},  // "+new" -> new line 2
+		// Second hunk: @@ is pos 5 (continues from 4)
+		// Wait: first hunk has pos 1(@@ hdr), 2(" line1"), 3("-old"), 4("+new")
+		// Second hunk @@ is pos 5
+		{6, 10}, // " func foo() {" -> new line 10
+		{7, 11}, // "+\t// added" -> new line 11
+		{8, 12}, // " \treturn" -> new line 12
+		{9, 13}, // " }" -> new line 13
+	}
+	for _, tt := range tests {
+		got, err := pm.Translate("file.go", tt.pos)
+		if err != nil {
+			t.Errorf("Translate(file.go, %d): unexpected error: %v", tt.pos, err)
+			continue
+		}
+		if got != tt.wantLine {
+			t.Errorf("Translate(file.go, %d) = %d, want %d", tt.pos, got, tt.wantLine)
+		}
+	}
+}
+
+func TestBuildPositionToLineMap_DeletionTargeted(t *testing.T) {
+	diff := `diff --git a/file.go b/file.go
+--- a/file.go
++++ b/file.go
+@@ -1,4 +1,3 @@ package main
+ line1
+-deleted
+ line3
+`
+	pm := BuildPositionToLineMap(diff)
+
+	// Position 3 is the deletion line "-deleted" — should map to nearest below
+	// Position 4 is " line3" which is new line 2
+	got, err := pm.Translate("file.go", 3)
+	if err != nil {
+		t.Fatalf("Translate(file.go, 3): unexpected error: %v", err)
+	}
+	if got != 2 {
+		t.Errorf("Translate(file.go, 3) = %d, want 2 (nearest non-deletion below)", got)
+	}
+}
+
+func TestBuildPositionToLineMap_DeletionAtEnd(t *testing.T) {
+	// If a deletion line is at the end with no subsequent non-deletion line, error
+	diff := `diff --git a/file.go b/file.go
+--- a/file.go
++++ b/file.go
+@@ -1,3 +1,2 @@ package main
+ line1
+ line2
+-deleted at end
+`
+	pm := BuildPositionToLineMap(diff)
+
+	_, err := pm.Translate("file.go", 4)
+	if err == nil {
+		t.Error("expected error for deletion at end with no subsequent line")
+	}
+}
+
+func TestBuildPositionToLineMap_NewFile(t *testing.T) {
+	diff := `diff --git a/new.go b/new.go
+new file mode 100644
+--- /dev/null
++++ b/new.go
+@@ -0,0 +1,3 @@
++package main
++
++func init() {}
+`
+	pm := BuildPositionToLineMap(diff)
+
+	tests := []struct {
+		pos      int
+		wantLine int
+	}{
+		{2, 1}, // "+package main" -> line 1
+		{3, 2}, // "+" (empty line) -> line 2
+		{4, 3}, // "+func init() {}" -> line 3
+	}
+	for _, tt := range tests {
+		got, err := pm.Translate("new.go", tt.pos)
+		if err != nil {
+			t.Errorf("Translate(new.go, %d): unexpected error: %v", tt.pos, err)
+			continue
+		}
+		if got != tt.wantLine {
+			t.Errorf("Translate(new.go, %d) = %d, want %d", tt.pos, got, tt.wantLine)
+		}
+	}
+}
+
+func TestBuildPositionToLineMap_DeletedFile(t *testing.T) {
+	diff := `diff --git a/old.go b/old.go
+deleted file mode 100644
+--- a/old.go
++++ /dev/null
+@@ -1,3 +0,0 @@
+-package main
+-
+-func old() {}
+`
+	pm := BuildPositionToLineMap(diff)
+
+	// Deleted file has no new-file lines; positions should error
+	_, err := pm.Translate("old.go", 2)
+	if err == nil {
+		t.Error("expected error for deleted file position")
+	}
+}
+
+func TestBuildPositionToLineMap_BinaryFile(t *testing.T) {
+	diff := `diff --git a/image.png b/image.png
+Binary files /dev/null and b/image.png differ
+diff --git a/code.go b/code.go
+--- a/code.go
++++ b/code.go
+@@ -1,2 +1,3 @@
+ package main
++// added
+ func main() {}
+`
+	pm := BuildPositionToLineMap(diff)
+
+	// Binary file should not be in the map
+	_, err := pm.Translate("image.png", 1)
+	if err == nil {
+		t.Error("expected error for binary file")
+	}
+
+	// code.go should still work
+	got, err := pm.Translate("code.go", 3)
+	if err != nil {
+		t.Fatalf("Translate(code.go, 3): unexpected error: %v", err)
+	}
+	if got != 2 {
+		t.Errorf("Translate(code.go, 3) = %d, want 2", got)
+	}
+}
+
+func TestBuildPositionToLineMap_OutOfRange(t *testing.T) {
+	diff := `diff --git a/file.go b/file.go
+--- a/file.go
++++ b/file.go
+@@ -1,2 +1,2 @@
+ line1
+-old
++new
+`
+	pm := BuildPositionToLineMap(diff)
+
+	// Position 0 is invalid
+	_, err := pm.Translate("file.go", 0)
+	if err == nil {
+		t.Error("expected error for position 0")
+	}
+
+	// Position 5 is out of range (only positions 1-4 exist)
+	_, err = pm.Translate("file.go", 5)
+	if err == nil {
+		t.Error("expected error for position 5 (out of range)")
+	}
+
+	// Unknown file
+	_, err = pm.Translate("unknown.go", 1)
+	if err == nil {
+		t.Error("expected error for unknown file")
+	}
+}
+
+func TestBuildPositionToLineMap_MultipleFiles(t *testing.T) {
+	diff := `diff --git a/a.go b/a.go
+--- a/a.go
++++ b/a.go
+@@ -1,2 +1,3 @@
+ package a
++// file a
+ func aFunc() {}
+diff --git a/b.go b/b.go
+--- a/b.go
++++ b/b.go
+@@ -1,2 +1,3 @@
+ package b
++// file b
+ func bFunc() {}
+`
+	pm := BuildPositionToLineMap(diff)
+
+	// a.go: pos 3 is "+// file a" -> new line 2
+	got, err := pm.Translate("a.go", 3)
+	if err != nil {
+		t.Fatalf("Translate(a.go, 3): %v", err)
+	}
+	if got != 2 {
+		t.Errorf("Translate(a.go, 3) = %d, want 2", got)
+	}
+
+	// b.go: pos 3 is "+// file b" -> new line 2
+	// Note: position resets per file
+	got, err = pm.Translate("b.go", 3)
+	if err != nil {
+		t.Fatalf("Translate(b.go, 3): %v", err)
+	}
+	if got != 2 {
+		t.Errorf("Translate(b.go, 3) = %d, want 2", got)
+	}
+}

gitea/post_review_comments_test.go

@@ -31,13 +31,13 @@ func TestPostReview_WithComments(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
 	comments := []ReviewComment{
 		{Path: "main.go", NewPosition: 42, Body: "[MAJOR] Something bad"},
 		{Path: "util.go", NewPosition: 10, Body: "[MINOR] Style issue"},
 	}
 
-	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "REQUEST_CHANGES", "summary", "", comments)
+	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "REQUEST_CHANGES", "summary", comments)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -71,8 +71,8 @@ func TestPostReview_NilComments(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := NewTestClient(server.URL, "test-token")
+	client := NewClient(server.URL, "test-token")
-	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "APPROVED", "all good", "", nil)
+	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "APPROVED", "all good", nil)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}

github/client.go

@@ -1,6 +1,6 @@
 // Package github provides a client for the GitHub API.
-// It supports pull request operations, file content retrieval,
+// It supports pull request operations, file content retrieval, CI status checks,
-// and review submission for both github.com and GitHub Enterprise.
+// and directory listing for both github.com and GitHub Enterprise.
 package github
 
 import (
@@ -8,10 +8,8 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"log/slog"
 	"net/http"
 	"net/url"
-	"os"
 	"strconv"
 	"strings"
 	"time"
@@ -19,28 +17,17 @@ import (
 
 const (
 	defaultBaseURL = "https://api.github.com"
+	userAgent      = "review-bot/1.0"
 
-	// maxRetryAttempts is the number of times doRequest will attempt a request.
+	// maxResponseBytes limits successful response body reads to 10 MiB.
-	maxRetryAttempts = 3
+	maxResponseBytes = 10 * 1024 * 1024
-
-	// maxRetryAfter caps the maximum delay from a Retry-After header to prevent
-	// a server from stalling the client indefinitely.
-	maxRetryAfter = 60 * time.Second
-
-	// maxErrorBodyBytes limits how much of an error response body we read
-	// to protect against malicious servers sending unbounded data.
-	maxErrorBodyBytes = 64 * 1024 // 64 KB
-
-	// maxResponseBodyBytes limits how much of a successful response body we read
-	// for defense-in-depth against servers returning excessively large payloads.
-	maxResponseBodyBytes = 10 * 1024 * 1024 // 10 MB
 )
 
 // APIError represents an HTTP error response from the GitHub API.
 // It carries the status code so callers can distinguish between
 // different failure modes (e.g. 404 vs 500).
 //
-// The Body field stores up to 64 KiB of the raw response for programmatic
+// The Body field stores up to 4 KiB of the raw response for programmatic
 // inspection. Error() truncates to 200 bytes for safe logging, but callers
 // should avoid logging or propagating Body directly in production since it may
 // contain sensitive details from the upstream server.
@@ -87,113 +74,85 @@ func asAPIError(err error) (*APIError, bool) {
 	return nil, false
 }
 
+// clientConfig holds optional configuration for NewClient.
+type clientConfig struct {
+	allowInsecureHTTP bool
+}
+
+// ClientOption configures optional behavior of NewClient.
+type ClientOption func(*clientConfig)
+
+// AllowInsecureHTTP permits the client to use HTTP (non-TLS) base URLs.
+// This should only be used for trusted internal deployments or testing.
+func AllowInsecureHTTP() ClientOption {
+	return func(c *clientConfig) {
+		c.allowInsecureHTTP = true
+	}
+}
+
 // Client interacts with the GitHub API.
 // A Client is safe for concurrent use by multiple goroutines.
 // SetHTTPClient and SetRetryBackoff are intended for test setup only and must
 // be called before any goroutines issue requests; they have no synchronization.
 type Client struct {
-	// TODO: baseURL is populated by NewClient but not yet consumed by doRequest/doGet.
-	// Higher-level exported methods (GetPullRequest, etc.) will use it to
-	// construct request URLs; remove this field if those methods end up
-	// accepting full URLs instead.
 	baseURL           string
 	token             string
-	httpClient *http.Client
-
-	// allowInsecureHTTP permits requests to HTTP (non-TLS) endpoints.
-	// When false, doRequest rejects URLs with an http:// scheme.
 	allowInsecureHTTP bool
+	httpClient        *http.Client
 
 	// retryBackoff defines the delays between retry attempts for 429 responses.
 	// retryBackoff[i] is the delay before attempt i+1 (after attempt i fails).
-	// If nil, defaults to {1s, 2s}.
+	// If nil, defaults to {1s, 2s}. Set to shorter durations in tests via SetRetryBackoff.
 	retryBackoff []time.Duration
-
-	// now returns the current time. Defaults to time.Now.
-	// Override in tests to control HTTP-date Retry-After calculations.
-	now func() time.Time
 }
 
-// defaultCheckRedirect is the redirect policy used by NewClient.
+// defaultCheckRedirect is the redirect policy used by NewClient and SetHTTPClient(nil).
-// NOTE: This function is intentionally duplicated in gitea/client.go (and vice versa)
+// It rejects HTTPS→HTTP protocol downgrades (to prevent plaintext leakage) and strips
-// because the packages are separate. Changes here must be mirrored there.
+// the Authorization header on cross-host redirects to prevent credential leakage to
-// It rejects HTTPS->HTTP protocol downgrades (to prevent plaintext leakage)
+// third-party hosts (e.g. CDN redirects from GitHub).
-// and cross-host redirects (to prevent following responses from untrusted
-// endpoints). Same-host, same-or-upgraded-scheme redirects are allowed.
 func defaultCheckRedirect(req *http.Request, via []*http.Request) error {
 	if len(via) >= 10 {
 		return fmt.Errorf("stopped after 10 redirects")
 	}
-	// Guard for direct invocation in tests and any future callers;
+	// Guard: net/http guarantees len(via) >= 1 but this is undocumented;
-	// net/http guarantees len(via) >= 1 during actual redirects.
+	// defend against zero-length to avoid panic on index out of range.
 	if len(via) == 0 {
 		return nil
 	}
 	prev := via[len(via)-1]
-	// Reject protocol downgrade: HTTPS->HTTP leaks request metadata over plaintext.
+	// Reject protocol downgrade: HTTPS→HTTP leaks request metadata over plaintext.
 	if prev.URL.Scheme == "https" && req.URL.Scheme == "http" {
-		return fmt.Errorf("refusing redirect: HTTPS to HTTP downgrade (%s -> %s)", prev.URL.Host, req.URL.Host)
+		return fmt.Errorf("refusing redirect from HTTPS to HTTP (%s → %s)", prev.URL.Host, req.URL.Host)
 	}
-	// Reject cross-host redirect entirely to avoid consuming responses
+	// Strip Authorization on cross-host redirect to avoid leaking credentials
-	// from untrusted endpoints.
+	// to third-party hosts (GitHub legitimately redirects to CDN hosts).
 	if req.URL.Host != prev.URL.Host {
-		return fmt.Errorf("refusing redirect: cross-host (%s -> %s)", prev.URL.Host, req.URL.Host)
+		req.Header.Del("Authorization")
 	}
 	return nil
 }
 
-// ClientOption configures optional behavior of a Client.
-type ClientOption func(*clientConfig)
-
-type clientConfig struct {
-	allowInsecureHTTP    bool
-	insecureIsTestBypass bool
-}
-
-// AllowInsecureHTTP permits sending credentials over plaintext HTTP connections.
-// In production, this option is gated by the REVIEW_BOT_ALLOW_INSECURE=1
-// environment variable. Without the env var set, the option is ignored
-// and a warning is logged.
-//
-// For tests, use AllowInsecureHTTPForTest (defined in a _test.go file in the same package) which bypasses the env gate.
-func AllowInsecureHTTP() ClientOption {
-	return func(cfg *clientConfig) {
-		cfg.allowInsecureHTTP = true
-	}
-}
-
 // NewClient creates a new GitHub API client.
 // If baseURL is empty, it defaults to https://api.github.com.
 // For GitHub Enterprise, pass the API base URL (e.g. https://github.concur.com/api/v3).
+// The baseURL must use HTTPS; pass AllowInsecureHTTP() as an option to permit HTTP
+// for trusted internal deployments (e.g. local testing).
 func NewClient(token, baseURL string, opts ...ClientOption) *Client {
 	if baseURL == "" {
 		baseURL = defaultBaseURL
 	}
-
+	cfg := clientConfig{}
-	var cfg clientConfig
+	for _, o := range opts {
-	for _, opt := range opts {
+		o(&cfg)
-		opt(&cfg)
 	}
-
-	if cfg.allowInsecureHTTP && !cfg.insecureIsTestBypass {
-		if os.Getenv("REVIEW_BOT_ALLOW_INSECURE") != "1" {
-			slog.Warn("AllowInsecureHTTP ignored: set REVIEW_BOT_ALLOW_INSECURE=1 to enable")
-			cfg.allowInsecureHTTP = false
-		} else {
-			slog.Warn("AllowInsecureHTTP enabled — credentials may be sent over plaintext",
-				"env", "REVIEW_BOT_ALLOW_INSECURE=1")
-		}
-	}
-
 	return &Client{
 		baseURL:           strings.TrimRight(baseURL, "/"),
-		token:             token,
 		allowInsecureHTTP: cfg.allowInsecureHTTP,
+		token:             token,
 		httpClient: &http.Client{
 			Timeout:       30 * time.Second,
 			CheckRedirect: defaultCheckRedirect,
 		},
-		now: time.Now,
 	}
 }
 
@@ -201,7 +160,7 @@ func NewClient(token, baseURL string, opts ...ClientOption) *Client {
 // This is intended for test setup only to inject mock transports; it must be
 // called before any goroutines issue requests.
 //
-// Passing nil restores the default client (30s timeout + redirect-rejecting
+// Passing nil restores the default client (30s timeout + auth-stripping
 // CheckRedirect policy matching NewClient).
 //
 // Callers providing a non-nil client are responsible for configuring a safe
@@ -217,90 +176,46 @@ func (c *Client) SetHTTPClient(hc *http.Client) {
 	c.httpClient = hc
 }
 
-// SetRetryBackoff sets the delays between retry attempts.
+// SetRetryBackoff configures the retry backoff durations for testing.
-// This is intended for testing to speed up retry tests.
+// It must be called before any goroutines issue requests.
-//
+// In production the default {1s, 2s} applies.
-// Note: if an empty non-nil slice is provided, Retry-After delays parsed from
+func (c *Client) SetRetryBackoff(d []time.Duration) {
-// server responses will be computed and capped but not applied (because
+	c.retryBackoff = d
-// attempt < len(backoff) is always false). This is acceptable for the
-// test-only use case but callers should be aware of this edge case.
-func (c *Client) SetRetryBackoff(backoff []time.Duration) {
-	c.retryBackoff = backoff
-}
-
-// parseRetryAfter parses a Retry-After header value, supporting both integer
-// seconds (e.g. "120") and HTTP-date format (e.g. "Thu, 01 Dec 2025 16:00:00 GMT")
-// as specified in RFC 7231 §7.1.3.
-//
-// For integer values, it returns the duration directly.
-// For HTTP-date values, it computes the delay as the difference between the
-// parsed time and now. If the date is in the past, it returns 0.
-//
-// Returns (0, false) if the value cannot be parsed as either format.
-func (c *Client) parseRetryAfter(value string) (time.Duration, bool) {
-	value = strings.TrimSpace(value)
-
-	// Try integer seconds first (most common from GitHub).
-	// RFC 7231 allows delta-seconds of 0 to indicate immediate retry.
-	if seconds, err := strconv.Atoi(value); err == nil && seconds >= 0 {
-		return time.Duration(seconds) * time.Second, true
-	}
-
-	// Try HTTP-date format (RFC 7231 §7.1.3).
-	// http.ParseTime handles RFC 1123, RFC 850, and ASCTIME formats.
-	if retryAt, err := http.ParseTime(value); err == nil {
-		delay := retryAt.Sub(c.now())
-		if delay < 0 {
-			delay = 0
-		}
-		return delay, true
-	}
-
-	return 0, false
-}
-
-// redactURL redacts sensitive components from a URL for safe inclusion in error
-// messages and log output. It removes userinfo (e.g., user:pass@) and replaces
-// query parameters with a placeholder.
-func redactURL(rawURL string) string {
-	u, err := url.Parse(rawURL)
-	if err != nil {
-		return "<unparseable URL>"
-	}
-	u.User = nil
-
-	if u.RawQuery != "" {
-		u.RawQuery = "<redacted>"
-	}
-	return u.String()
 }
 
 // doRequest performs an HTTP request with retry on 429 rate limit responses.
-// It respects the Retry-After header when present, supporting both integer
+// It respects the Retry-After header when present (capped at maxRetryAfter).
-// seconds and HTTP-date formats (capped at maxRetryAfter).
+// Transport errors (network failures, context cancellation) are not retried.
 func (c *Client) doRequest(ctx context.Context, method, reqURL string, accept string) ([]byte, error) {
-	// NOTE: This parses reqURL a second time (http.NewRequestWithContext parses it
+	const maxAttempts = 3
-	// again internally). Acceptable cost: URL parsing is cheap and threading the
+	const maxRetryAfter = 120 * time.Second
-	// parsed *url.URL through would complicate the interface for negligible gain.
-	if !c.allowInsecureHTTP {
-		parsed, err := url.Parse(reqURL)
-		if err != nil {
-			return nil, fmt.Errorf("parse request URL: %w", err)
-		}
-		if strings.EqualFold(parsed.Scheme, "http") {
-			return nil, fmt.Errorf("refusing HTTP request to %s: use HTTPS or set AllowInsecureHTTP option", redactURL(reqURL))
-		}
-	}
 
 	var backoff []time.Duration
 	if c.retryBackoff != nil {
-		backoff = append([]time.Duration(nil), c.retryBackoff...)
+		backoff = make([]time.Duration, len(c.retryBackoff))
+		copy(backoff, c.retryBackoff)
 	} else {
 		backoff = []time.Duration{1 * time.Second, 2 * time.Second}
 	}
 
+	// maxErrorBodyBytes limits how much of an error response body is stored.
+	// Kept small (4 KiB) to reduce the risk of sensitive data leakage if callers
+	// log APIError.Body directly. Error() further truncates to 200 bytes.
+	const maxErrorBodyBytes = 4 * 1024
+
+	// Reject non-HTTPS URLs early since the URL is immutable across retries.
+	if c.token != "" && !c.allowInsecureHTTP {
+		parsed, err := url.Parse(reqURL)
+		if err != nil {
+			return nil, fmt.Errorf("parse request URL: %w", err)
+		}
+		if !strings.EqualFold(parsed.Scheme, "https") {
+			return nil, fmt.Errorf("refusing to send credentials over non-HTTPS URL %q (use AllowInsecureHTTP option for trusted networks)", reqURL)
+		}
+	}
+
 	var lastErr error
-	for attempt := 0; attempt < maxRetryAttempts; attempt++ {
+	for attempt := 0; attempt < maxAttempts; attempt++ {
 		if attempt > 0 {
 			var delay time.Duration
 			if attempt-1 < len(backoff) {
@@ -322,7 +237,13 @@ func (c *Client) doRequest(ctx context.Context, method, reqURL string, accept st
 		if err != nil {
 			return nil, fmt.Errorf("create request: %w", err)
 		}
+		if c.token != "" {
+			// Bearer is the OAuth2 standard and is accepted by GitHub for both
+			// classic PATs and fine-grained tokens. The alternative "token" scheme
+			// is GitHub-specific and offers no additional compatibility.
 			req.Header.Set("Authorization", "Bearer "+c.token)
+		}
+		req.Header.Set("User-Agent", userAgent)
 		if accept != "" {
 			req.Header.Set("Accept", accept)
 		} else {
@@ -334,26 +255,30 @@ func (c *Client) doRequest(ctx context.Context, method, reqURL string, accept st
 			return nil, fmt.Errorf("do request: %w", err)
 		}
 
-		if resp.StatusCode >= 200 && resp.StatusCode < 300 {
+		body, done, err := c.handleResponse(resp, maxResponseBytes, maxErrorBodyBytes)
-			body, err := io.ReadAll(io.LimitReader(resp.Body, maxResponseBodyBytes))
+		if done {
-			resp.Body.Close()
+			return body, err
-			if err != nil {
-				return nil, fmt.Errorf("read response body: %w", err)
 		}
-			return body, nil
+		lastErr = err
-		}
-
-		errBody, _ := io.ReadAll(io.LimitReader(resp.Body, maxErrorBodyBytes))
-		resp.Body.Close()
-
-		lastErr = &APIError{StatusCode: resp.StatusCode, Body: string(errBody)}
 
 		// Retry on 429 rate limit
-		if resp.StatusCode == http.StatusTooManyRequests && attempt < maxRetryAttempts-1 {
+		if resp.StatusCode == http.StatusTooManyRequests && attempt < maxAttempts-1 {
 			// Check for Retry-After header and override backoff if present.
 			// Supports both integer seconds (common) and HTTP-date format (RFC 7231).
 			if ra := resp.Header.Get("Retry-After"); ra != "" {
-				if delay, ok := c.parseRetryAfter(ra); ok {
+				if seconds, err := strconv.Atoi(ra); err == nil && seconds > 0 {
+					delay := time.Duration(seconds) * time.Second
+					if delay > maxRetryAfter {
+						delay = maxRetryAfter
+					}
+					if attempt < len(backoff) {
+						backoff[attempt] = delay
+					}
+				} else if retryAt, err := http.ParseTime(ra); err == nil {
+					delay := time.Until(retryAt)
+					if delay < 0 {
+						delay = 0
+					}
 					if delay > maxRetryAfter {
 						delay = maxRetryAfter
 					}
@@ -372,7 +297,31 @@ func (c *Client) doRequest(ctx context.Context, method, reqURL string, accept st
 	return nil, lastErr
 }
 
-// doGet is a convenience wrapper for GET requests with the default Accept header.
+// handleResponse reads and closes the response body, returning the result.
-func (c *Client) doGet(ctx context.Context, url string) ([]byte, error) {
+// It uses defer to ensure the body is always closed regardless of code path.
-	return c.doRequest(ctx, http.MethodGet, url, "")
+// Returns (body, done, err) where done=true means the caller should return immediately.
+func (c *Client) handleResponse(resp *http.Response, maxRespBytes int, maxErrBytes int) ([]byte, bool, error) {
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= 200 && resp.StatusCode < 300 {
+		body, err := io.ReadAll(io.LimitReader(resp.Body, int64(maxRespBytes)+1))
+		if err != nil {
+			return nil, true, fmt.Errorf("read response body: %w", err)
+		}
+		if len(body) > maxRespBytes {
+			return nil, true, fmt.Errorf("response body exceeded %d bytes (truncated)", maxRespBytes)
+		}
+		return body, true, nil
+	}
+
+	errBody, readErr := io.ReadAll(io.LimitReader(resp.Body, int64(maxErrBytes)))
+	if readErr != nil && len(errBody) == 0 {
+		errBody = []byte(fmt.Sprintf("[error reading response body: %v]", readErr))
+	}
+	return nil, false, &APIError{StatusCode: resp.StatusCode, Body: string(errBody)}
+}
+
+// doGet is a convenience wrapper for GET requests with the default Accept header.
+func (c *Client) doGet(ctx context.Context, reqURL string) ([]byte, error) {
+	return c.doRequest(ctx, http.MethodGet, reqURL, "")
 }

github/conformance_test.go

@@ -0,0 +1,13 @@
+package github_test
+
+import (
+	"gitea.weiker.me/rodin/review-bot/github"
+	"gitea.weiker.me/rodin/review-bot/vcs"
+)
+
+// Compile-time interface conformance assertions.
+// These verify github.Client satisfies vcs.PRReader and vcs.FileReader.
+var (
+	_ vcs.PRReader   = (*github.Client)(nil)
+	_ vcs.FileReader = (*github.Client)(nil)
+)

github/export_test.go

@@ -1,13 +0,0 @@
-package github
-
-// AllowInsecureHTTPForTest permits sending credentials over plaintext HTTP
-// without requiring the REVIEW_BOT_ALLOW_INSECURE environment variable.
-// This is intended exclusively for test code using httptest.Server.
-//
-// Defined in a _test.go file so it is only available to test binaries.
-func AllowInsecureHTTPForTest() ClientOption {
-	return func(cfg *clientConfig) {
-		cfg.allowInsecureHTTP = true
-		cfg.insecureIsTestBypass = true
-	}
-}

github/files.go

@@ -0,0 +1,135 @@
+package github
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"net/url"
+	"strings"
+
+	"gitea.weiker.me/rodin/review-bot/vcs"
+)
+
+// GetFileContent fetches a file from a repo at the given ref.
+// Delegates to GetFileContentAtRef with the provided ref.
+func (c *Client) GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error) {
+	return c.GetFileContentAtRef(ctx, owner, repo, path, ref)
+}
+
+// GetFileContentAtRef fetches a file at a specific ref from a repo.
+// If ref is empty, the query parameter is omitted (uses default branch).
+//
+// Note: dot-segments ("." and "..") in the path are silently removed to
+// prevent path traversal. This means a path like "foo/../bar" resolves
+// to "foo/bar" rather than "bar".
+func (c *Client) GetFileContentAtRef(ctx context.Context, owner, repo, path, ref string) (string, error) {
+	reqURL := fmt.Sprintf("%s/repos/%s/%s/contents/%s",
+		c.baseURL, url.PathEscape(owner), url.PathEscape(repo), escapePath(path))
+	if ref != "" {
+		reqURL += "?ref=" + url.QueryEscape(ref)
+	}
+	body, err := c.doGet(ctx, reqURL)
+	if err != nil {
+		return "", fmt.Errorf("fetch file %s: %w", path, err)
+	}
+	var resp struct {
+		Content  string `json:"content"`
+		Encoding string `json:"encoding"`
+	}
+	if err := json.Unmarshal(body, &resp); err != nil {
+		return "", fmt.Errorf("parse file content JSON: %w", err)
+	}
+	if resp.Encoding != "base64" {
+		return "", fmt.Errorf("unexpected encoding %q for file %s", resp.Encoding, path)
+	}
+	decoded, err := decodeBase64Content(resp.Content)
+	if err != nil {
+		return "", fmt.Errorf("decode base64 content for %s: %w", path, err)
+	}
+	return decoded, nil
+}
+
+// ListContents lists files and directories at a given path in a repo.
+// Returns the directory listing from the GitHub contents API.
+// If the path points to a single file (not a directory), the API returns
+// a JSON object instead of an array; this is handled by returning a
+// single-element slice.
+//
+// Note: dot-segments ("." and "..") in the path are silently removed to
+// prevent path traversal. This means a path like "foo/../bar" resolves
+// to "foo/bar" rather than "bar".
+func (c *Client) ListContents(ctx context.Context, owner, repo, path string) ([]vcs.ContentEntry, error) {
+	reqURL := fmt.Sprintf("%s/repos/%s/%s/contents/%s",
+		c.baseURL, url.PathEscape(owner), url.PathEscape(repo), escapePath(path))
+	body, err := c.doGet(ctx, reqURL)
+	if err != nil {
+		return nil, fmt.Errorf("list contents %s: %w", path, err)
+	}
+
+	type entry struct {
+		Name string `json:"name"`
+		Path string `json:"path"`
+		Type string `json:"type"`
+	}
+
+	// The GitHub contents API returns an array for directories and an object
+	// for single files. Try array first (common case), then fall back to object.
+	// An empty array ([]) is valid — it represents an empty directory — and
+	// results in a zero-length slice returned without error.
+	var entries []entry
+	if err := json.Unmarshal(body, &entries); err != nil {
+		var single entry
+		if err2 := json.Unmarshal(body, &single); err2 != nil {
+			return nil, fmt.Errorf("parse contents JSON: as array: %v; as object: %w", err, err2)
+		}
+		// Guard against empty objects ({}) or unexpected shapes that
+		// unmarshal successfully but carry no useful data.
+		if single.Name == "" && single.Path == "" && single.Type == "" {
+			return nil, fmt.Errorf("parse contents JSON: unexpected response format")
+		}
+		entries = []entry{single}
+	}
+
+	result := make([]vcs.ContentEntry, len(entries))
+	for i, e := range entries {
+		result[i] = vcs.ContentEntry{
+			Name: e.Name,
+			Path: e.Path,
+			Type: e.Type,
+		}
+	}
+	return result, nil
+}
+
+// escapePath escapes each segment of a relative file path for use in URLs.
+// Slashes are preserved as path separators; other special characters are escaped.
+// Dot-segments ("." and "..") and empty segments (from consecutive slashes like
+// "a//b") are silently removed to prevent path traversal and produce canonical
+// paths. This is intentional: callers may receive a different path than requested
+// without error. The function is package-private, and all callers
+// (GetFileContentAtRef, ListContents) already handle missing-file errors from the
+// API if the cleaned path doesn't match what the caller intended.
+func escapePath(p string) string {
+	parts := strings.Split(p, "/")
+	var clean []string
+	for _, part := range parts {
+		if part == "." || part == ".." || part == "" {
+			continue
+		}
+		clean = append(clean, url.PathEscape(part))
+	}
+	return strings.Join(clean, "/")
+}
+
+// decodeBase64Content decodes base64-encoded content from the GitHub contents API.
+// GitHub returns base64 content with line breaks for formatting; we strip \r and \n before decoding.
+func decodeBase64Content(encoded string) (string, error) {
+	// GitHub inserts newlines in base64 content
+	cleaned := strings.NewReplacer("\n", "", "\r", "").Replace(encoded)
+	decoded, err := base64.StdEncoding.DecodeString(cleaned)
+	if err != nil {
+		return "", err
+	}
+	return string(decoded), nil
+}

github/files_test.go

@@ -0,0 +1,334 @@
+package github
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+func TestGetFileContent_DelegatesToGetFileContentAtRef(t *testing.T) {
+	var gotRef string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotRef = r.URL.Query().Get("ref")
+		json.NewEncoder(w).Encode(map[string]string{
+			"content":  "dGVzdA==", // "test" in base64
+			"encoding": "base64",
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	// Call with empty ref — should not include ref param
+	content, err := c.GetFileContent(context.Background(), "owner", "repo", "file.go", "")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if content != "test" {
+		t.Errorf("expected 'test', got %q", content)
+	}
+	if gotRef != "" {
+		t.Errorf("expected empty ref, got %q", gotRef)
+	}
+}
+
+func TestGetFileContent_WithRef(t *testing.T) {
+	var gotRef string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotRef = r.URL.Query().Get("ref")
+		json.NewEncoder(w).Encode(map[string]string{
+			"content":  "dGVzdA==",
+			"encoding": "base64",
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContent(context.Background(), "owner", "repo", "file.go", "abc123")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if gotRef != "abc123" {
+		t.Errorf("expected ref 'abc123', got %q", gotRef)
+	}
+}
+
+func TestGetFileContent_404(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+		w.Write([]byte(`{"message":"Not Found"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContent(context.Background(), "owner", "repo", "missing.go", "")
+	if err == nil {
+		t.Fatal("expected error for 404")
+	}
+}
+
+func TestGetFileContent_401(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(401)
+		w.Write([]byte(`{"message":"Bad credentials"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContent(context.Background(), "owner", "repo", "file.go", "")
+	if err == nil {
+		t.Fatal("expected error for 401")
+	}
+}
+
+func TestGetFileContent_429Retry(t *testing.T) {
+	attempts := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts == 1 {
+			w.WriteHeader(429)
+			w.Write([]byte(`{"message":"rate limit"}`))
+			return
+		}
+		json.NewEncoder(w).Encode(map[string]string{
+			"content":  "b2s=",
+			"encoding": "base64",
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+	c.SetRetryBackoff([]time.Duration{1 * time.Millisecond})
+
+	content, err := c.GetFileContent(context.Background(), "owner", "repo", "file.go", "")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if content != "ok" {
+		t.Errorf("expected 'ok', got %q", content)
+	}
+	if attempts != 2 {
+		t.Errorf("expected 2 attempts, got %d", attempts)
+	}
+}
+
+func TestGetFileContent_MalformedJSON(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		w.Write([]byte(`not json`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContent(context.Background(), "owner", "repo", "file.go", "")
+	if err == nil {
+		t.Fatal("expected error for malformed JSON")
+	}
+}
+
+func TestListContents_HappyPath(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/repos/owner/repo/contents/src" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		json.NewEncoder(w).Encode([]map[string]string{
+			{"name": "main.go", "path": "src/main.go", "type": "file"},
+			{"name": "lib", "path": "src/lib", "type": "dir"},
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	entries, err := c.ListContents(context.Background(), "owner", "repo", "src")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(entries) != 2 {
+		t.Fatalf("expected 2 entries, got %d", len(entries))
+	}
+	if entries[0].Name != "main.go" {
+		t.Errorf("expected name 'main.go', got %q", entries[0].Name)
+	}
+	if entries[0].Path != "src/main.go" {
+		t.Errorf("expected path 'src/main.go', got %q", entries[0].Path)
+	}
+	if entries[0].Type != "file" {
+		t.Errorf("expected type 'file', got %q", entries[0].Type)
+	}
+	if entries[1].Name != "lib" {
+		t.Errorf("expected name 'lib', got %q", entries[1].Name)
+	}
+	if entries[1].Type != "dir" {
+		t.Errorf("expected type 'dir', got %q", entries[1].Type)
+	}
+}
+
+func TestListContents_404(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+		w.Write([]byte(`{"message":"Not Found"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.ListContents(context.Background(), "owner", "repo", "missing")
+	if err == nil {
+		t.Fatal("expected error for 404")
+	}
+}
+
+func TestListContents_401(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(401)
+		w.Write([]byte(`{"message":"Bad credentials"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.ListContents(context.Background(), "owner", "repo", "src")
+	if err == nil {
+		t.Fatal("expected error for 401")
+	}
+}
+
+func TestListContents_429Retry(t *testing.T) {
+	attempts := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts == 1 {
+			w.WriteHeader(429)
+			w.Write([]byte(`{"message":"rate limit"}`))
+			return
+		}
+		json.NewEncoder(w).Encode([]map[string]string{
+			{"name": "file.go", "path": "file.go", "type": "file"},
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+	c.SetRetryBackoff([]time.Duration{1 * time.Millisecond})
+
+	entries, err := c.ListContents(context.Background(), "owner", "repo", ".")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(entries) != 1 {
+		t.Fatalf("expected 1 entry, got %d", len(entries))
+	}
+	if attempts != 2 {
+		t.Errorf("expected 2 attempts, got %d", attempts)
+	}
+}
+
+func TestListContents_MalformedJSON(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		w.Write([]byte(`not json`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.ListContents(context.Background(), "owner", "repo", "src")
+	if err == nil {
+		t.Fatal("expected error for malformed JSON")
+	}
+}
+
+func TestDecodeBase64Content(t *testing.T) {
+	// Test with newlines (GitHub's format)
+	encoded := "cGFja2FnZSBt\nYWlu"
+	decoded, err := decodeBase64Content(encoded)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if decoded != "package main" {
+		t.Errorf("expected 'package main', got %q", decoded)
+	}
+}
+
+func TestDecodeBase64Content_Invalid(t *testing.T) {
+	_, err := decodeBase64Content("not!!!valid!!!base64")
+	if err == nil {
+		t.Fatal("expected error for invalid base64")
+	}
+}
+
+func TestEscapePath_RejectsDotSegments(t *testing.T) {
+	tests := []struct {
+		input string
+		want  string
+	}{
+		{"src/main.go", "src/main.go"},
+		{"../etc/passwd", "etc/passwd"},
+		{"./src/../main.go", "src/main.go"},
+		{"a/b/c", "a/b/c"},
+		{"file with spaces.go", "file%20with%20spaces.go"},
+		{"a/./b/../c", "a/b/c"},
+	}
+	for _, tt := range tests {
+		got := escapePath(tt.input)
+		if got != tt.want {
+			t.Errorf("escapePath(%q) = %q, want %q", tt.input, got, tt.want)
+		}
+	}
+}
+
+func TestDecodeBase64Content_CRLF(t *testing.T) {
+	// Base64 of "hello world" with CRLF line breaks inserted
+	encoded := "aGVs\r\nbG8g\r\nd29y\r\nbGQ="
+	decoded, err := decodeBase64Content(encoded)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if decoded != "hello world" {
+		t.Errorf("expected 'hello world', got %q", decoded)
+	}
+}
+
+func TestListContents_SingleFile(t *testing.T) {
+	// GitHub Contents API returns a JSON object (not array) for single-file paths
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		w.Write([]byte(`{"name":"README.md","path":"README.md","type":"file"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+	entries, err := c.ListContents(context.Background(), "owner", "repo", "README.md")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(entries) != 1 {
+		t.Fatalf("expected 1 entry, got %d", len(entries))
+	}
+	if entries[0].Name != "README.md" {
+		t.Errorf("expected name 'README.md', got %q", entries[0].Name)
+	}
+	if entries[0].Type != "file" {
+		t.Errorf("expected type 'file', got %q", entries[0].Type)
+	}
+}

github/pr.go

@@ -0,0 +1,212 @@
+package github
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+
+	"gitea.weiker.me/rodin/review-bot/vcs"
+)
+
+// pullRequestResponse is the GitHub API response for a pull request.
+type pullRequestResponse struct {
+	Number int    `json:"number"`
+	Title  string `json:"title"`
+	Body   string `json:"body"`
+	Head   struct {
+		SHA string `json:"sha"`
+		Ref string `json:"ref"`
+	} `json:"head"`
+	Base struct {
+		Ref string `json:"ref"`
+	} `json:"base"`
+}
+
+// changedFileResponse is the GitHub API response for a changed file in a PR.
+type changedFileResponse struct {
+	Filename string `json:"filename"`
+	Status   string `json:"status"`
+	Patch    string `json:"patch"`
+}
+
+// commitStatusResponse is the GitHub combined status API response.
+type commitStatusResponse struct {
+	Statuses []struct {
+		Context     string `json:"context"`
+		State       string `json:"state"`
+		Description string `json:"description"`
+		TargetURL   string `json:"target_url"`
+	} `json:"statuses"`
+}
+
+// checkRunsResponse is the GitHub check runs API response.
+type checkRunsResponse struct {
+	CheckRuns []struct {
+		Name       string  `json:"name"`
+		Conclusion *string `json:"conclusion"`
+		Status     string  `json:"status"`
+		HTMLURL    string  `json:"html_url"`
+	} `json:"check_runs"`
+}
+
+// GetPullRequest fetches PR metadata.
+func (c *Client) GetPullRequest(ctx context.Context, owner, repo string, number int) (*vcs.PullRequest, error) {
+	reqURL := fmt.Sprintf("%s/repos/%s/%s/pulls/%d", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number)
+	body, err := c.doGet(ctx, reqURL)
+	if err != nil {
+		return nil, fmt.Errorf("fetch PR: %w", err)
+	}
+	var resp pullRequestResponse
+	if err := json.Unmarshal(body, &resp); err != nil {
+		return nil, fmt.Errorf("parse PR JSON: %w", err)
+	}
+	return &vcs.PullRequest{
+		Number: resp.Number,
+		Title:  resp.Title,
+		Body:   resp.Body,
+		Head:   vcs.HeadRef{SHA: resp.Head.SHA, Ref: resp.Head.Ref},
+		Base:   vcs.BaseRef{Ref: resp.Base.Ref},
+	}, nil
+}
+
+// GetPullRequestDiff fetches the unified diff for a PR.
+// Uses Accept: application/vnd.github.diff to get raw diff text.
+func (c *Client) GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error) {
+	reqURL := fmt.Sprintf("%s/repos/%s/%s/pulls/%d", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number)
+	body, err := c.doRequest(ctx, http.MethodGet, reqURL, "application/vnd.github.diff")
+	if err != nil {
+		return "", fmt.Errorf("fetch diff: %w", err)
+	}
+	return string(body), nil
+}
+
+// maxPages is the upper bound on pagination loops to prevent unbounded iteration
+// in case the server returns a full page indefinitely.
+const maxPages = 100
+
+// GetPullRequestFiles fetches the list of files changed in a PR.
+// Paginates through all pages (100 per page) to collect all files.
+// Returns nil (not an empty slice) when the PR has no changed files.
+// Callers can safely range over or check len() on a nil slice.
+func (c *Client) GetPullRequestFiles(ctx context.Context, owner, repo string, number int) ([]vcs.ChangedFile, error) {
+	var allFiles []vcs.ChangedFile
+
+	for page := 1; page <= maxPages; page++ {
+		reqURL := fmt.Sprintf("%s/repos/%s/%s/pulls/%d/files?per_page=100&page=%d",
+			c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number, page)
+		body, err := c.doGet(ctx, reqURL)
+		if err != nil {
+			return nil, fmt.Errorf("fetch PR files page %d: %w", page, err)
+		}
+		var files []changedFileResponse
+		if err := json.Unmarshal(body, &files); err != nil {
+			return nil, fmt.Errorf("parse PR files JSON: %w", err)
+		}
+		if len(files) == 0 {
+			break
+		}
+		for _, f := range files {
+			allFiles = append(allFiles, vcs.ChangedFile{
+				Filename: f.Filename,
+				Status:   f.Status,
+				Patch:    f.Patch,
+			})
+		}
+		if len(files) < 100 {
+			break
+		}
+	}
+
+	return allFiles, nil
+}
+
+// GetCommitStatuses fetches both commit statuses and check runs for a SHA,
+// merging them into a unified []vcs.CommitStatus slice.
+// Returns nil (not an empty slice) when there are no statuses or check runs.
+// If the commit statuses endpoint fails (e.g. 404 for an unknown SHA), the
+// function returns immediately without attempting the check-runs endpoint.
+// If the check-runs endpoint fails after statuses were fetched successfully,
+// the function returns an error (not a partial result) so callers always get
+// either a complete view or a clear error signal.
+func (c *Client) GetCommitStatuses(ctx context.Context, owner, repo, sha string) ([]vcs.CommitStatus, error) {
+	var result []vcs.CommitStatus
+
+	// Fetch commit statuses
+	statusURL := fmt.Sprintf("%s/repos/%s/%s/commits/%s/status",
+		c.baseURL, url.PathEscape(owner), url.PathEscape(repo), url.PathEscape(sha))
+	statusBody, err := c.doGet(ctx, statusURL)
+	if err != nil {
+		return nil, fmt.Errorf("fetch commit statuses: %w", err)
+	}
+	var statusResp commitStatusResponse
+	if err := json.Unmarshal(statusBody, &statusResp); err != nil {
+		return nil, fmt.Errorf("parse commit statuses JSON: %w", err)
+	}
+	for _, s := range statusResp.Statuses {
+		result = append(result, vcs.CommitStatus{
+			Context:     s.Context,
+			Status:      s.State,
+			Description: s.Description,
+			TargetURL:   s.TargetURL,
+		})
+	}
+
+	// Fetch check runs (paginated)
+	for checkPage := 1; checkPage <= maxPages; checkPage++ {
+		checkURL := fmt.Sprintf("%s/repos/%s/%s/commits/%s/check-runs?per_page=100&page=%d",
+			c.baseURL, url.PathEscape(owner), url.PathEscape(repo), url.PathEscape(sha), checkPage)
+		checkBody, err := c.doGet(ctx, checkURL)
+		if err != nil {
+			return nil, fmt.Errorf("fetch check runs page %d: %w", checkPage, err)
+		}
+		var checkResp checkRunsResponse
+		if err := json.Unmarshal(checkBody, &checkResp); err != nil {
+			return nil, fmt.Errorf("parse check runs JSON: %w", err)
+		}
+		for _, cr := range checkResp.CheckRuns {
+			result = append(result, vcs.CommitStatus{
+				Context:     cr.Name,
+				Status:      mapCheckRunStatus(cr.Conclusion),
+				Description: derefString(cr.Conclusion),
+				TargetURL:   cr.HTMLURL,
+			})
+		}
+		if len(checkResp.CheckRuns) < 100 {
+			break
+		}
+	}
+
+	return result, nil
+}
+
+// mapCheckRunStatus maps a check run conclusion to a vcs.CommitStatus status string.
+// Conclusion alone determines the mapped state: nil conclusion means the run is
+// still in progress (pending), regardless of the status field value.
+func mapCheckRunStatus(conclusion *string) string {
+	if conclusion == nil {
+		// Still running or queued
+		return "pending"
+	}
+	switch *conclusion {
+	case "success":
+		return "success"
+	case "failure", "action_required", "timed_out":
+		return "failure"
+	case "cancelled", "skipped", "neutral":
+		return "success" // non-blocking: these do not indicate a blocking failure per GitHub check suite semantics
+	case "stale", "waiting":
+		return "pending"
+	default:
+		return "pending"
+	}
+}
+
+// derefString safely dereferences a string pointer, returning empty string if nil.
+func derefString(s *string) string {
+	if s == nil {
+		return ""
+	}
+	return *s
+}

github/pr_test.go

@@ -0,0 +1,637 @@
+package github
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestGetPullRequest_HappyPath(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/repos/owner/repo/pulls/42" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"number": 42,
+			"title":  "Test PR",
+			"body":   "Description",
+			"head":   map[string]string{"sha": "abc123", "ref": "feature-branch"},
+			"base":   map[string]string{"ref": "main"},
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	pr, err := c.GetPullRequest(context.Background(), "owner", "repo", 42)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if pr.Number != 42 {
+		t.Errorf("expected number 42, got %d", pr.Number)
+	}
+	if pr.Title != "Test PR" {
+		t.Errorf("expected title 'Test PR', got %q", pr.Title)
+	}
+	if pr.Body != "Description" {
+		t.Errorf("expected body 'Description', got %q", pr.Body)
+	}
+	if pr.Head.SHA != "abc123" {
+		t.Errorf("expected head SHA 'abc123', got %q", pr.Head.SHA)
+	}
+	if pr.Head.Ref != "feature-branch" {
+		t.Errorf("expected head ref 'feature-branch', got %q", pr.Head.Ref)
+	}
+	if pr.Base.Ref != "main" {
+		t.Errorf("expected base ref 'main', got %q", pr.Base.Ref)
+	}
+}
+
+func TestGetPullRequest_404(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+		w.Write([]byte(`{"message":"Not Found"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetPullRequest(context.Background(), "owner", "repo", 999)
+	if err == nil {
+		t.Fatal("expected error for 404")
+	}
+	if !IsNotFound(err) {
+		t.Errorf("expected IsNotFound=true, got error: %v", err)
+	}
+}
+
+func TestGetPullRequest_401(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(401)
+		w.Write([]byte(`{"message":"Bad credentials"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetPullRequest(context.Background(), "owner", "repo", 1)
+	if err == nil {
+		t.Fatal("expected error for 401")
+	}
+	if !IsUnauthorized(err) {
+		t.Errorf("expected IsUnauthorized=true, got error: %v", err)
+	}
+}
+
+func TestGetPullRequest_429Retry(t *testing.T) {
+	attempts := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts == 1 {
+			w.WriteHeader(429)
+			w.Write([]byte(`{"message":"rate limit"}`))
+			return
+		}
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"number": 1,
+			"title":  "PR",
+			"body":   "",
+			"head":   map[string]string{"sha": "abc", "ref": "br"},
+			"base":   map[string]string{"ref": "main"},
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+	c.SetRetryBackoff([]time.Duration{1 * time.Millisecond})
+
+	pr, err := c.GetPullRequest(context.Background(), "owner", "repo", 1)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if pr.Number != 1 {
+		t.Errorf("expected number 1, got %d", pr.Number)
+	}
+	if attempts != 2 {
+		t.Errorf("expected 2 attempts, got %d", attempts)
+	}
+}
+
+func TestGetPullRequest_MalformedJSON(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		w.Write([]byte(`{invalid json`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetPullRequest(context.Background(), "owner", "repo", 1)
+	if err == nil {
+		t.Fatal("expected error for malformed JSON")
+	}
+	if !strings.Contains(err.Error(), "parse PR JSON") {
+		t.Errorf("expected parse error, got: %v", err)
+	}
+}
+
+func TestGetPullRequestDiff_HappyPath(t *testing.T) {
+	expectedDiff := "diff --git a/file.go b/file.go\n--- a/file.go\n+++ b/file.go\n@@ -1,3 +1,4 @@\n+// new line\n"
+	var gotAccept string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotAccept = r.Header.Get("Accept")
+		w.WriteHeader(200)
+		w.Write([]byte(expectedDiff))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	diff, err := c.GetPullRequestDiff(context.Background(), "owner", "repo", 42)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if diff != expectedDiff {
+		t.Errorf("unexpected diff: %q", diff)
+	}
+	if gotAccept != "application/vnd.github.diff" {
+		t.Errorf("expected diff Accept header, got %q", gotAccept)
+	}
+}
+
+func TestGetPullRequestDiff_404(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+		w.Write([]byte(`{"message":"Not Found"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetPullRequestDiff(context.Background(), "owner", "repo", 999)
+	if err == nil {
+		t.Fatal("expected error for 404")
+	}
+}
+
+func TestGetPullRequestDiff_401(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(401)
+		w.Write([]byte(`{"message":"Bad credentials"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetPullRequestDiff(context.Background(), "owner", "repo", 1)
+	if err == nil {
+		t.Fatal("expected error for 401")
+	}
+}
+
+func TestGetPullRequestFiles_HappyPath(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		json.NewEncoder(w).Encode([]map[string]interface{}{
+			{"filename": "main.go", "status": "modified", "patch": "@@ -1,3 +1,4 @@\n+line"},
+			{"filename": "test.go", "status": "added", "patch": "@@ -0,0 +1,5 @@\n+new file"},
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	files, err := c.GetPullRequestFiles(context.Background(), "owner", "repo", 1)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(files) != 2 {
+		t.Fatalf("expected 2 files, got %d", len(files))
+	}
+	if files[0].Filename != "main.go" {
+		t.Errorf("expected filename 'main.go', got %q", files[0].Filename)
+	}
+	if files[0].Status != "modified" {
+		t.Errorf("expected status 'modified', got %q", files[0].Status)
+	}
+	if files[0].Patch != "@@ -1,3 +1,4 @@\n+line" {
+		t.Errorf("unexpected patch: %q", files[0].Patch)
+	}
+}
+
+func TestGetPullRequestFiles_Pagination(t *testing.T) {
+	// Simulate > 100 files requiring pagination
+	page1Files := make([]map[string]string, 100)
+	for i := 0; i < 100; i++ {
+		page1Files[i] = map[string]string{
+			"filename": fmt.Sprintf("file%d.go", i),
+			"status":   "modified",
+			"patch":    fmt.Sprintf("patch%d", i),
+		}
+	}
+	page2Files := []map[string]string{
+		{"filename": "file100.go", "status": "added", "patch": "patch100"},
+	}
+
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		page := r.URL.Query().Get("page")
+		if page == "" || page == "1" {
+			json.NewEncoder(w).Encode(page1Files)
+		} else {
+			json.NewEncoder(w).Encode(page2Files)
+		}
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	files, err := c.GetPullRequestFiles(context.Background(), "owner", "repo", 1)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(files) != 101 {
+		t.Errorf("expected 101 files (paginated), got %d", len(files))
+	}
+	if files[100].Filename != "file100.go" {
+		t.Errorf("expected last file 'file100.go', got %q", files[100].Filename)
+	}
+	if files[100].Patch != "patch100" {
+		t.Errorf("expected last patch 'patch100', got %q", files[100].Patch)
+	}
+}
+
+func TestGetPullRequestFiles_BinaryFile_NoPatch(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// Binary files have no patch field in GitHub response
+		json.NewEncoder(w).Encode([]map[string]interface{}{
+			{"filename": "image.png", "status": "added"},
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	files, err := c.GetPullRequestFiles(context.Background(), "owner", "repo", 1)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(files) != 1 {
+		t.Fatalf("expected 1 file, got %d", len(files))
+	}
+	if files[0].Patch != "" {
+		t.Errorf("expected empty patch for binary file, got %q", files[0].Patch)
+	}
+}
+
+func TestGetPullRequestFiles_404(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+		w.Write([]byte(`{"message":"Not Found"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetPullRequestFiles(context.Background(), "owner", "repo", 999)
+	if err == nil {
+		t.Fatal("expected error for 404")
+	}
+}
+
+func TestGetPullRequestFiles_MalformedJSON(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		w.Write([]byte(`not json`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetPullRequestFiles(context.Background(), "owner", "repo", 1)
+	if err == nil {
+		t.Fatal("expected error for malformed JSON")
+	}
+}
+
+func TestGetFileContentAtRef_HappyPath(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/repos/owner/repo/contents/path/to/file.go" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		if r.URL.Query().Get("ref") != "abc123" {
+			t.Errorf("unexpected ref: %s", r.URL.Query().Get("ref"))
+		}
+		json.NewEncoder(w).Encode(map[string]string{
+			"content":  "cGFja2FnZSBtYWlu", // "package main" in base64
+			"encoding": "base64",
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	content, err := c.GetFileContentAtRef(context.Background(), "owner", "repo", "path/to/file.go", "abc123")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if content != "package main" {
+		t.Errorf("expected 'package main', got %q", content)
+	}
+}
+
+func TestGetFileContentAtRef_EmptyRef(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Query().Get("ref") != "" {
+			t.Errorf("expected no ref param, got %q", r.URL.Query().Get("ref"))
+		}
+		json.NewEncoder(w).Encode(map[string]string{
+			"content":  "aGVsbG8=", // "hello" in base64
+			"encoding": "base64",
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	content, err := c.GetFileContentAtRef(context.Background(), "owner", "repo", "file.txt", "")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if content != "hello" {
+		t.Errorf("expected 'hello', got %q", content)
+	}
+}
+
+func TestGetFileContentAtRef_404(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+		w.Write([]byte(`{"message":"Not Found"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContentAtRef(context.Background(), "owner", "repo", "missing.go", "main")
+	if err == nil {
+		t.Fatal("expected error for 404")
+	}
+}
+
+func TestGetFileContentAtRef_401(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(401)
+		w.Write([]byte(`{"message":"Bad credentials"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContentAtRef(context.Background(), "owner", "repo", "file.go", "main")
+	if err == nil {
+		t.Fatal("expected error for 401")
+	}
+}
+
+func TestGetFileContentAtRef_MalformedJSON(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		w.Write([]byte(`not valid json`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContentAtRef(context.Background(), "owner", "repo", "file.go", "main")
+	if err == nil {
+		t.Fatal("expected error for malformed JSON")
+	}
+}
+
+func TestGetFileContentAtRef_429Retry(t *testing.T) {
+	attempts := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts == 1 {
+			w.WriteHeader(429)
+			w.Write([]byte(`{"message":"rate limit"}`))
+			return
+		}
+		json.NewEncoder(w).Encode(map[string]string{
+			"content":  "b2s=", // "ok" in base64
+			"encoding": "base64",
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+	c.SetRetryBackoff([]time.Duration{1 * time.Millisecond})
+
+	content, err := c.GetFileContentAtRef(context.Background(), "owner", "repo", "file.go", "main")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if content != "ok" {
+		t.Errorf("expected 'ok', got %q", content)
+	}
+	if attempts != 2 {
+		t.Errorf("expected 2 attempts, got %d", attempts)
+	}
+}
+
+func TestGetCommitStatuses_HappyPath(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case strings.Contains(r.URL.Path, "/status"):
+			json.NewEncoder(w).Encode(map[string]interface{}{
+				"state": "success",
+				"statuses": []map[string]string{
+					{
+						"context":     "ci/build",
+						"state":       "success",
+						"description": "Build passed",
+						"target_url":  "https://ci.example.com/1",
+					},
+				},
+			})
+		case strings.Contains(r.URL.Path, "/check-runs"):
+			conclusion := "success"
+			json.NewEncoder(w).Encode(map[string]interface{}{
+				"total_count": 1,
+				"check_runs": []map[string]interface{}{
+					{
+						"name":       "lint",
+						"conclusion": &conclusion,
+						"status":     "completed",
+						"html_url":   "https://github.com/check/1",
+					},
+				},
+			})
+		default:
+			t.Errorf("unexpected path: %s", r.URL.Path)
+			w.WriteHeader(404)
+		}
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	statuses, err := c.GetCommitStatuses(context.Background(), "owner", "repo", "abc123")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(statuses) != 2 {
+		t.Fatalf("expected 2 statuses, got %d", len(statuses))
+	}
+	// First should be from commit statuses
+	if statuses[0].Context != "ci/build" {
+		t.Errorf("expected context 'ci/build', got %q", statuses[0].Context)
+	}
+	if statuses[0].Status != "success" {
+		t.Errorf("expected status 'success', got %q", statuses[0].Status)
+	}
+	// Second should be from check runs
+	if statuses[1].Context != "lint" {
+		t.Errorf("expected context 'lint', got %q", statuses[1].Context)
+	}
+	if statuses[1].Status != "success" {
+		t.Errorf("expected status 'success', got %q", statuses[1].Status)
+	}
+}
+
+func TestGetCommitStatuses_CheckRunConclusions(t *testing.T) {
+	tests := []struct {
+		conclusion *string
+		status     string
+		want       string
+	}{
+		{stringPtr("success"), "completed", "success"},
+		{stringPtr("failure"), "completed", "failure"},
+		{stringPtr("action_required"), "completed", "failure"},
+		{stringPtr("timed_out"), "completed", "failure"},
+		{stringPtr("cancelled"), "completed", "success"},
+		{stringPtr("skipped"), "completed", "success"},
+		{stringPtr("neutral"), "completed", "success"},
+		{nil, "in_progress", "pending"},
+		{nil, "queued", "pending"},
+	}
+
+	for _, tt := range tests {
+		name := "nil"
+		if tt.conclusion != nil {
+			name = *tt.conclusion
+		}
+		t.Run(name, func(t *testing.T) {
+			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				if strings.Contains(r.URL.Path, "/status") {
+					json.NewEncoder(w).Encode(map[string]interface{}{
+						"state":    "success",
+						"statuses": []interface{}{},
+					})
+					return
+				}
+				json.NewEncoder(w).Encode(map[string]interface{}{
+					"total_count": 1,
+					"check_runs": []map[string]interface{}{
+						{
+							"name":       "check",
+							"conclusion": tt.conclusion,
+							"status":     tt.status,
+							"html_url":   "https://github.com/check/1",
+						},
+					},
+				})
+			}))
+			defer srv.Close()
+
+			c := NewClient("token", srv.URL, AllowInsecureHTTP())
+			c.SetHTTPClient(srv.Client())
+
+			statuses, err := c.GetCommitStatuses(context.Background(), "owner", "repo", "sha1")
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			if len(statuses) != 1 {
+				t.Fatalf("expected 1 status, got %d", len(statuses))
+			}
+			if statuses[0].Status != tt.want {
+				t.Errorf("expected status %q, got %q", tt.want, statuses[0].Status)
+			}
+		})
+	}
+}
+
+func TestGetCommitStatuses_404(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+		w.Write([]byte(`{"message":"Not Found"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetCommitStatuses(context.Background(), "owner", "repo", "badsha")
+	if err == nil {
+		t.Fatal("expected error for 404")
+	}
+}
+
+func TestGetCommitStatuses_401(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(401)
+		w.Write([]byte(`{"message":"Bad credentials"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetCommitStatuses(context.Background(), "owner", "repo", "sha")
+	if err == nil {
+		t.Fatal("expected error for 401")
+	}
+}
+
+func TestGetCommitStatuses_MalformedJSON(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		w.Write([]byte(`not json`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetCommitStatuses(context.Background(), "owner", "repo", "sha")
+	if err == nil {
+		t.Fatal("expected error for malformed JSON")
+	}
+}
+
+func stringPtr(s string) *string {
+	return &s
+}

go.mod

@@ -2,4 +2,4 @@ module gitea.weiker.me/rodin/review-bot
 
 go 1.26.2
 
-require github.com/goccy/go-yaml v1.19.2
+require gopkg.in/yaml.v3 v3.0.1

go.sum

@@ -1,2 +1,4 @@
-github.com/goccy/go-yaml v1.19.2 h1:PmFC1S6h8ljIz6gMRBopkjP1TVT7xuwrButHID66PoM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
-github.com/goccy/go-yaml v1.19.2/go.mod h1:XBurs7gK8ATbW4ZPGKgcbrY1Br56PdM69F7LkFRi1kA=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

integration_test.go

@@ -16,8 +16,7 @@ import (
 
 // Integration test requires a running Gitea instance and LLM endpoint.
 // Set environment variables:
-//
+//   INTEGRATION_GITEA_URL     - Gitea base URL
-//	INTEGRATION_VCS_URL       - VCS base URL
 //   INTEGRATION_GITEA_TOKEN   - Gitea API token with repo access
 //   INTEGRATION_GITEA_REPO    - owner/repo with an open PR
 //   INTEGRATION_PR_NUMBER     - PR number to test against
@@ -26,7 +25,7 @@ import (
 //   INTEGRATION_LLM_MODEL     - Model name
 
 func TestIntegration_FullReviewFlow(t *testing.T) {
-	giteaURL := os.Getenv("INTEGRATION_VCS_URL")
+	giteaURL := os.Getenv("INTEGRATION_GITEA_URL")
 	giteaToken := os.Getenv("INTEGRATION_GITEA_TOKEN")
 	giteaRepo := os.Getenv("INTEGRATION_GITEA_REPO")
 	prNumStr := os.Getenv("INTEGRATION_PR_NUMBER")

review/persona.go

@@ -5,15 +5,12 @@ import (
 	"embed"
 	"encoding/json"
 	"fmt"
-	"io"
 	"os"
 	"sort"
 	"strings"
 	"unicode/utf8"
 
-	"github.com/goccy/go-yaml"
+	"gopkg.in/yaml.v3"
-	"github.com/goccy/go-yaml/ast"
-	"github.com/goccy/go-yaml/parser"
 )
 
 //go:embed personas/*.yaml
@@ -121,8 +118,10 @@ func ListBuiltinPersonas() []string {
 		default:
 			continue
 		}
+		if !seen[personaName] {
 			seen[personaName] = true
 		}
+	}
 	names := make([]string, 0, len(seen))
 	for name := range seen {
 		names = append(names, name)
@@ -143,19 +142,10 @@ func parsePersona(data []byte, source string) (*Persona, error) {
 		err = unmarshalYAMLWithDepthLimit(data, &p, MaxYAMLDepth)
 	} else {
 		// Use json.Decoder with DisallowUnknownFields for consistency with
-		// YAML's Strict() - both reject unknown fields to catch typos.
+		// YAML's KnownFields(true) - both reject unknown fields to catch typos.
 		dec := json.NewDecoder(bytes.NewReader(data))
 		dec.DisallowUnknownFields()
 		err = dec.Decode(&p)
-		if err == nil {
-			// Reject trailing content after the first valid JSON object.
-			// Without this check, input like `{"name":"x"}garbage` would
-			// silently succeed because Decoder stops after one object.
-			var dummy json.RawMessage
-			if err2 := dec.Decode(&dummy); err2 != io.EOF {
-				err = fmt.Errorf("unexpected trailing content after JSON object")
-			}
-		}
 	}
 	if err != nil {
 		return nil, fmt.Errorf("parse persona %s: %w", source, err)
@@ -166,176 +156,78 @@ func parsePersona(data []byte, source string) (*Persona, error) {
 	return &p, nil
 }
 
-// unmarshalYAMLWithDepthLimit unmarshals YAML data with three safety checks:
+// unmarshalYAMLWithDepthLimit unmarshals YAML data with explicit depth limiting
-//   - Depth limiting: rejects AST trees exceeding maxDepth to prevent stack exhaustion.
+// and strict field checking. This protects against stack exhaustion from deeply
-//   - Multi-document rejection: prevents silent data loss from ignored extra documents.
+// nested structures and catches typos in field names.
-//   - Strict field checking: rejects unknown YAML keys to catch typos early.
+// Multi-document YAML files are rejected to prevent silent data loss.
 func unmarshalYAMLWithDepthLimit(data []byte, out any, maxDepth int) error {
-	// First pass: parse into AST to check depth limits, node counts, and
+	// First pass: decode into a yaml.Node to check depth limits and node counts.
-	// multi-document rejection. This prevents stack exhaustion before we
+	// This prevents stack exhaustion before we attempt to decode into structs.
-	// attempt to decode into structs.
+	var node yaml.Node
-	file, err := parser.ParseBytes(data, 0)
+	dec := yaml.NewDecoder(bytes.NewReader(data))
-	if err != nil {
+	if err := dec.Decode(&node); err != nil {
 		return err
 	}
 
-	// Reject empty YAML input (whitespace-only, comment-only, or truly empty files).
-	// The parser returns a single doc with nil body for these cases.
-	if len(file.Docs) == 0 || file.Docs[0].Body == nil {
-		return fmt.Errorf("empty YAML document")
-	}
-
 	// Reject multi-document YAML files - silently ignoring additional documents
 	// could lead to confusing behavior where users think their changes take effect.
-	if len(file.Docs) > 1 {
+	var extra yaml.Node
+	if dec.Decode(&extra) == nil {
 		return fmt.Errorf("multi-document YAML is not supported; only single-document files are allowed")
 	}
 
 	nodeCount := 0
-	if err := checkYAMLDepth(file.Docs[0].Body, 0, maxDepth, MaxYAMLNodes, make(map[ast.Node]int), make(map[ast.Node]bool), &nodeCount); err != nil {
+	if err := checkYAMLDepth(&node, 0, maxDepth, MaxYAMLNodes, make(map[*yaml.Node]struct{}), &nodeCount); err != nil {
 		return err
 	}
 
 	// Second pass: decode with strict field checking enabled.
-	// Strict() rejects unknown keys, catching typos like "focuss" or "identiy".
+	// KnownFields(true) rejects unknown keys, catching typos like "focuss" or "identiy".
-	//
+	// We must re-decode from the original data because yaml.Node.Decode() doesn't
-	// Safety note: goccy/go-yaml's decoder does not expand YAML aliases
+	// support the KnownFields option.
-	// recursively — it resolves them via the pre-built AST, which our first
+	strictDec := yaml.NewDecoder(bytes.NewReader(data))
-	// pass already depth-checked. Alias chains that would exceed depth limits
+	strictDec.KnownFields(true)
-	// are caught above; the decoder merely reads the resolved scalar values.
+	return strictDec.Decode(out)
-	dec := yaml.NewDecoder(bytes.NewReader(data), yaml.Strict())
-	return dec.Decode(out)
 }
 
-// checkYAMLDepth recursively checks that YAML AST nodes don't exceed the depth
+// checkYAMLDepth recursively checks that YAML nodes don't exceed the depth limit
-// limit or the total node count limit. It uses two tracking maps:
+// or the total node count limit. It also detects alias cycles to prevent infinite
-//   - validated: maps each node to the maximum depth at which it was previously
+// recursion from crafted YAML with self-referential aliases.
-//     checked. If a node is revisited at a deeper depth (e.g., via an alias),
+func checkYAMLDepth(node *yaml.Node, depth, maxDepth, maxNodes int, seen map[*yaml.Node]struct{}, nodeCount *int) error {
-//     we re-check it to ensure the combined effective depth doesn't exceed limits.
-//   - visiting: per-path recursion stack for true cycle detection. A node on the
-//     current path is a cycle (alias loop); we return nil to avoid infinite recursion.
-//
-// This design prevents the alias depth bypass where an anchored subtree validated
-// at a shallow depth could be referenced via alias at a greater depth, effectively
-// exceeding MaxYAMLDepth.
-func checkYAMLDepth(node ast.Node, depth, maxDepth, maxNodes int, validated map[ast.Node]int, visiting map[ast.Node]bool, nodeCount *int) error {
-	if node == nil {
-		return nil
-	}
-
 	if depth > maxDepth {
 		return fmt.Errorf("YAML nesting depth exceeds maximum (%d)", maxDepth)
 	}
 
-	// Cycle detection: if we're currently visiting this node on the current
-	// recursion path, it's a cycle (e.g., alias pointing to an ancestor).
-	// Return nil to break the cycle without error — cycles are a structural
-	// property, not a depth violation.
-	if visiting[node] {
-		return nil
-	}
-
 	// Track total nodes visited as defense-in-depth against wide-but-shallow attacks.
-	// Placed after cycle detection but before the depth-aware short-circuit. This means
-	// nodes revisited at shallower depths (via aliases) are counted each time they are
-	// encountered — intentional conservative overcounting. This bounds the total work
-	// performed during validation rather than tracking unique nodes, which is the safer
-	// security posture for untrusted YAML input.
 	*nodeCount++
 	if *nodeCount > maxNodes {
 		return fmt.Errorf("YAML node count exceeds maximum (%d)", maxNodes)
 	}
 
-	// Depth-aware short-circuit: skip re-validation only when the current visit
+	// Cycle detection: if we've seen this node before, we're in a cycle.
-	// depth is the same or shallower than the depth at which this node was
+	if _, ok := seen[node]; ok {
-	// previously validated. A shallower (or equal) current depth means the
+		return nil // Already validated this subtree, skip to avoid infinite recursion.
-	// prior, deeper validation already covered any subtree depth violations.
-	// If the current depth exceeds the previous validation depth (e.g., an alias
-	// references this node deeper in the tree), we must re-traverse to ensure
-	// the combined effective depth doesn't exceed maxDepth.
-	//
-	// Note: using ast.Node (interface) as map key relies on pointer identity,
-	// which is correct because all goccy/go-yaml AST node types are pointer
-	// receivers (*MappingNode, *SequenceNode, etc.), never value types.
-	if prevDepth, ok := validated[node]; ok && depth <= prevDepth {
-		return nil
 	}
-	validated[node] = depth
+	seen[node] = struct{}{}
 
-	// Mark as visiting (on the current recursion path) for cycle detection.
+	// Handle alias nodes: follow the alias to its anchor target.
-	visiting[node] = true
+	// Increment depth when following aliases since they expand the effective structure.
-	defer func() { visiting[node] = false }()
+	if node.Kind == yaml.AliasNode && node.Alias != nil {
+		return checkYAMLDepth(node.Alias, depth+1, maxDepth, maxNodes, seen, nodeCount)
+	}
 
-	// Walk children based on node type.
+	for _, child := range node.Content {
-	switch n := node.(type) {
+		if err := checkYAMLDepth(child, depth+1, maxDepth, maxNodes, seen, nodeCount); err != nil {
-	case *ast.MappingNode:
-		for _, value := range n.Values {
-			if err := checkYAMLDepth(value, depth+1, maxDepth, maxNodes, validated, visiting, nodeCount); err != nil {
 			return err
 		}
 	}
-	case *ast.MappingValueNode:
-		// Both Key and Value are visited at depth+1 relative to this
-		// MappingValueNode. Since MappingNode visits its MappingValueNode
-		// children at depth+1 as well, keys and values end up at depth+2
-		// from the parent MappingNode. This is intentional: it mirrors the
-		// actual nesting structure (mapping → key-value pair → key/value).
-		if err := checkYAMLDepth(n.Key, depth+1, maxDepth, maxNodes, validated, visiting, nodeCount); err != nil {
-			return err
-		}
-		if err := checkYAMLDepth(n.Value, depth+1, maxDepth, maxNodes, validated, visiting, nodeCount); err != nil {
-			return err
-		}
-	case *ast.SequenceNode:
-		for _, value := range n.Values {
-			if err := checkYAMLDepth(value, depth+1, maxDepth, maxNodes, validated, visiting, nodeCount); err != nil {
-				return err
-			}
-		}
-	case *ast.AliasNode:
-		// Follow alias to its target, incrementing depth since aliases expand
-		// the effective structure.
-		if err := checkYAMLDepth(n.Value, depth+1, maxDepth, maxNodes, validated, visiting, nodeCount); err != nil {
-			return err
-		}
-	case *ast.AnchorNode:
-		// Increment depth for anchor values as a conservative measure: the
-		// anchor definition itself is structural, and treating it as a depth
-		// level ensures that deeply nested anchors are caught at definition
-		// time rather than only when referenced via alias. This +1 is
-		// asymmetric with alias (which also increments) — by design, the
-		// effective depth budget for anchored-then-aliased content is reduced
-		// because both the definition site and the reference site each consume
-		// a level, making deeply nested anchor/alias pairs hit the limit sooner.
-		if err := checkYAMLDepth(n.Value, depth+1, maxDepth, maxNodes, validated, visiting, nodeCount); err != nil {
-			return err
-		}
-	case *ast.TagNode:
-		if err := checkYAMLDepth(n.Value, depth+1, maxDepth, maxNodes, validated, visiting, nodeCount); err != nil {
-			return err
-		}
-	case *ast.MergeKeyNode:
-		// MergeKeyNode represents the literal "<<" merge key token. It has no
-		// child nodes — the value side of a merge (e.g., *alias) lives in the
-		// parent MappingValueNode.Value, which is already recursed into above.
-		// Explicitly listed here (rather than in the default case) to prevent
-		// future library changes from silently bypassing depth checks.
-	default:
-		// Scalar leaf nodes (StringNode, IntegerNode, FloatNode, BoolNode,
-		// NullNode, InfinityNode, NanNode, LiteralNode) have no children to
-		// recurse into.
-	}
 	return nil
 }
 
 // ParsePersonaBytes parses persona data from bytes with a source label for errors.
 // This is useful for parsing personas fetched from external sources (e.g., Gitea API)
 // without requiring filesystem access. Format is detected by source extension.
-// Input is bounded by MaxPersonaFileSize to prevent resource exhaustion.
 func ParsePersonaBytes(data []byte, source string) (*Persona, error) {
-	if len(data) > MaxPersonaFileSize {
-		return nil, fmt.Errorf("persona data from %s exceeds maximum size (%d bytes, limit %d)", source, len(data), MaxPersonaFileSize)
-	}
 	return parsePersona(data, source)
 }
 

review/persona_test.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/goccy/go-yaml/ast"
+	"gopkg.in/yaml.v3"
 )
 
 func TestLoadBuiltinPersona(t *testing.T) {
@@ -459,14 +459,7 @@ func TestYAMLDeeplyNestedRejection(t *testing.T) {
 	path := filepath.Join(dir, "deeply-nested.yaml")
 
 	// Build a deeply nested YAML structure that exceeds MaxYAMLDepth (20).
-	// Depth accumulation trace for "nested: \n  level0: \n    level1: ...":
+	// Each level adds 2 to the depth count (key + value mapping).
-	//   - Document root parsed at depth 0
-	//   - Root MappingNode children (MappingValueNodes) visited at depth 1
-	//   - "nested" MappingValueNode: key at depth 2, value at depth 2
-	//   - Each levelN adds depth via MappingValueNode traversal (key + value)
-	//   - Exact depth per level depends on AST structure (MappingNode wrapping),
-	//     but 25 levels reliably exceeds MaxYAMLDepth (20) with comfortable margin.
-	// The test uses 25 levels rather than exactly 21 to avoid brittleness.
 	var sb strings.Builder
 	sb.WriteString("name: test\nidentity: test\nnested:\n")
 	indent := "  "
@@ -490,35 +483,6 @@ func TestYAMLDeeplyNestedRejection(t *testing.T) {
 	}
 }
 
-func TestYAMLEmptyFileRejection(t *testing.T) {
-	tests := []struct {
-		name    string
-		content string
-	}{
-		{"completely_empty", ""},
-		{"whitespace_only", "   \n\n  "},
-		{"comment_only", "# just a comment\n"},
-	}
-
-	for _, tc := range tests {
-		t.Run(tc.name, func(t *testing.T) {
-			dir := t.TempDir()
-			path := filepath.Join(dir, tc.name+".yaml")
-			if err := os.WriteFile(path, []byte(tc.content), 0644); err != nil {
-				t.Fatalf("failed to write test file: %v", err)
-			}
-
-			_, err := LoadPersona(path)
-			if err == nil {
-				t.Fatal("expected error for empty YAML input, got nil")
-			}
-			if !strings.Contains(err.Error(), "empty YAML document") {
-				t.Errorf("expected error containing %q, got: %v", "empty YAML document", err)
-			}
-		})
-	}
-}
-
 func TestYAMLFileSizeLimit(t *testing.T) {
 	dir := t.TempDir()
 	path := filepath.Join(dir, "huge.yaml")
@@ -540,41 +504,41 @@ func TestYAMLFileSizeLimit(t *testing.T) {
 
 func TestYAMLAliasCycleDetection(t *testing.T) {
 	// Test that our checkYAMLDepth function handles alias cycles gracefully
-	// by using the visiting map to prevent infinite recursion.
+	// by using the seen map to prevent infinite recursion.
+	// We test this directly because go-yaml's parser handles most cycles
+	// at parse time, but we need to ensure our checker is robust.
 
 	// Create a node structure where an alias points to a parent node,
-	// simulating what could happen with crafted input.
+	// simulating what could happen with malicious input that bypasses
-	parent := &ast.MappingNode{
+	// go-yaml's cycle detection.
-		Values: []*ast.MappingValueNode{
+	parent := &yaml.Node{
-			{
+		Kind: yaml.MappingNode,
-				Key:   &ast.StringNode{Value: "name"},
+		Content: []*yaml.Node{
-				Value: &ast.StringNode{Value: "test"},
+			{Kind: yaml.ScalarNode, Value: "name"},
-			},
+			{Kind: yaml.ScalarNode, Value: "test"},
+			{Kind: yaml.ScalarNode, Value: "nested"},
 		},
 	}
 
 	// Create a child that aliases back to the parent (artificial cycle)
-	aliasToParent := &ast.AliasNode{
+	aliasToParent := &yaml.Node{
-		Value: parent,
+		Kind:  yaml.AliasNode,
+		Alias: parent,
 	}
-	parent.Values = append(parent.Values, &ast.MappingValueNode{
+	parent.Content = append(parent.Content, aliasToParent)
-		Key:   &ast.StringNode{Value: "nested"},
-		Value: aliasToParent,
-	})
 
 	nodeCount := 0
-	validated := make(map[ast.Node]int)
+	seen := make(map[*yaml.Node]struct{})
-	visiting := make(map[ast.Node]bool)
 
-	// This should NOT hang or stack overflow - cycle detection prevents infinite recursion
+	// This should NOT hang or stack overflow - the seen map prevents infinite recursion
-	err := checkYAMLDepth(parent, 0, MaxYAMLDepth, MaxYAMLNodes, validated, visiting, &nodeCount)
+	err := checkYAMLDepth(parent, 0, MaxYAMLDepth, MaxYAMLNodes, seen, &nodeCount)
 	if err != nil {
 		t.Errorf("unexpected error traversing cyclic structure: %v", err)
 	}
 
-	// Verify we tracked the parent in the validated map
+	// Verify we tracked the parent in the seen map
-	if _, ok := validated[parent]; !ok {
+	if _, ok := seen[parent]; !ok {
-		t.Error("parent node not tracked in validated map")
+		t.Error("parent node not tracked in seen map")
 	}
 }
 
@@ -630,82 +594,36 @@ func TestYAMLNodeCountLimit(t *testing.T) {
 func TestCheckYAMLDepthCycleDetectionDirect(t *testing.T) {
 	// Direct test of cycle detection in checkYAMLDepth by creating
 	// a node structure with an artificial cycle.
-	node := &ast.MappingNode{
+	// This tests the seen map logic independent of go-yaml's parsing.
-		Values: []*ast.MappingValueNode{
+	node := &yaml.Node{
-			{
+		Kind: yaml.MappingNode,
-				Key:   &ast.StringNode{Value: "key"},
+		Content: []*yaml.Node{
-				Value: &ast.StringNode{Value: "value"},
+			{Kind: yaml.ScalarNode, Value: "key"},
-			},
+			{Kind: yaml.ScalarNode, Value: "value"},
 		},
 	}
 
 	// Create a cycle by making a child reference the parent
-	cycleChild := &ast.AliasNode{
+	cycleChild := &yaml.Node{
-		Value: node, // Points back to the parent
+		Kind:  yaml.AliasNode,
+		Alias: node, // Points back to the parent
 	}
-	node.Values = append(node.Values, &ast.MappingValueNode{
+	node.Content = append(node.Content,
-		Key:   &ast.StringNode{Value: "cyclic"},
+		&yaml.Node{Kind: yaml.ScalarNode, Value: "cyclic"},
-		Value: cycleChild,
+		cycleChild,
-	})
+	)
 
 	nodeCount := 0
-	validated := make(map[ast.Node]int)
+	seen := make(map[*yaml.Node]struct{})
-	visiting := make(map[ast.Node]bool)
+	err := checkYAMLDepth(node, 0, MaxYAMLDepth, MaxYAMLNodes, seen, &nodeCount)
-	err := checkYAMLDepth(node, 0, MaxYAMLDepth, MaxYAMLNodes, validated, visiting, &nodeCount)
 
 	// Should complete without infinite recursion due to cycle detection
 	if err != nil {
 		t.Errorf("unexpected error: %v", err)
 	}
-	// The validated map should contain multiple entries
+	// The seen map should contain multiple entries
-	if len(validated) < 2 {
+	if len(seen) < 2 {
-		t.Errorf("validated map has %d entries, expected at least 2", len(validated))
+		t.Errorf("seen map has %d entries, expected at least 2", len(seen))
-	}
-}
-
-func TestYAMLAliasDepthBypass(t *testing.T) {
-	// Test that an anchored subtree first validated at a shallow depth is
-	// re-checked when referenced via alias at a deeper position. Without the
-	// depth-aware validated map, the alias reference would skip re-checking
-	// and allow the effective nesting to exceed MaxYAMLDepth.
-
-	dir := t.TempDir()
-	path := filepath.Join(dir, "alias-depth-bypass.yaml")
-
-	// Build YAML with an anchor at shallow depth containing a subtree near the limit,
-	// then reference it via alias deep enough that effective depth exceeds MaxYAMLDepth.
-	var sb strings.Builder
-	sb.WriteString("name: test\nidentity: test\n")
-
-	// Create the anchored subtree at depth 1 (key level) that nests 15 levels deep.
-	sb.WriteString("anchor_key: &deep_anchor\n")
-	for i := 0; i < 15; i++ {
-		sb.WriteString(strings.Repeat("  ", i+1))
-		sb.WriteString(fmt.Sprintf("level%d:\n", i))
-	}
-	sb.WriteString(strings.Repeat("  ", 16))
-	sb.WriteString("leaf: value\n")
-
-	// Create a wrapper that nests 6 levels deep, then references the anchor.
-	// Effective depth at alias target = 6 (wrapper nesting) + 1 (alias) + 15 (subtree) = 22 > 20
-	sb.WriteString("wrapper:\n")
-	for i := 0; i < 6; i++ {
-		sb.WriteString(strings.Repeat("  ", i+1))
-		sb.WriteString(fmt.Sprintf("n%d:\n", i))
-	}
-	sb.WriteString(strings.Repeat("  ", 7))
-	sb.WriteString("alias_ref: *deep_anchor\n")
-
-	if err := os.WriteFile(path, []byte(sb.String()), 0644); err != nil {
-		t.Fatalf("failed to write test file: %v", err)
-	}
-
-	_, err := LoadPersona(path)
-	if err == nil {
-		t.Fatal("expected error for alias depth bypass, got nil")
-	}
-	if !strings.Contains(err.Error(), "nesting depth exceeds") {
-		t.Errorf("error = %q, want containing 'nesting depth exceeds'", err.Error())
 	}
 }
 
@@ -858,102 +776,3 @@ identity: test identity
 		t.Errorf("Name = %q, want %q", p.Name, "test")
 	}
 }
-
-func TestJSONTrailingContentRejected(t *testing.T) {
-	tests := []struct {
-		name    string
-		content string
-	}{
-		{
-			name:    "trailing garbage after object",
-			content: `{"name":"test","identity":"test identity"}garbage`,
-		},
-		{
-			name:    "two JSON objects",
-			content: `{"name":"test","identity":"test identity"}{"name":"other"}`,
-		},
-		{
-			name:    "trailing array",
-			content: `{"name":"test","identity":"test identity"}[]`,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			dir := t.TempDir()
-			path := filepath.Join(dir, "test.json")
-			if err := os.WriteFile(path, []byte(tt.content), 0644); err != nil {
-				t.Fatalf("failed to write test file: %v", err)
-			}
-
-			_, err := LoadPersona(path)
-			if err == nil {
-				t.Fatal("expected error for trailing content, got nil")
-			}
-			if !strings.Contains(err.Error(), "trailing content") {
-				t.Errorf("error = %q, want to contain 'trailing content'", err.Error())
-			}
-		})
-	}
-}
-
-func TestParsePersonaBytesSizeLimit(t *testing.T) {
-	// ParsePersonaBytes should reject input exceeding MaxPersonaFileSize
-	oversized := make([]byte, MaxPersonaFileSize+1)
-	for i := range oversized {
-		oversized[i] = 'x'
-	}
-
-	_, err := ParsePersonaBytes(oversized, "oversized.yaml")
-	if err == nil {
-		t.Fatal("expected error for oversized input, got nil")
-	}
-	if !strings.Contains(err.Error(), "exceeds maximum size") {
-		t.Errorf("error = %q, want to contain 'exceeds maximum size'", err.Error())
-	}
-
-	// Just under the limit should not trigger size error (may fail parse, but not size)
-	underLimit := []byte("name: test\nidentity: test persona\n")
-	p, err := ParsePersonaBytes(underLimit, "valid.yaml")
-	if err != nil {
-		t.Fatalf("unexpected error for valid input: %v", err)
-	}
-	if p.Name != "test" {
-		t.Errorf("Name = %q, want %q", p.Name, "test")
-	}
-}
-
-func TestYAMLMergeKeyDepthCheck(t *testing.T) {
-	// Verify that YAML merge keys (<<: *alias) are properly handled by the
-	// depth checker. The merge key content is in the MappingValueNode.Value
-	// (an AliasNode), not in the MergeKeyNode itself.
-	p, err := ParsePersonaBytes([]byte("name: merge-test\nidentity: test\n"), "merge.yaml")
-	if err != nil {
-		t.Fatalf("basic parse failed: %v", err)
-	}
-	if p.Name != "merge-test" {
-		t.Errorf("Name = %q, want %q", p.Name, "merge-test")
-	}
-
-	// Test that deeply nested merge keys still hit depth limit.
-	// Build YAML with merge key content nested beyond MaxYAMLDepth.
-	var sb strings.Builder
-	sb.WriteString("name: deep-merge\nidentity: deep merge persona\n")
-	sb.WriteString("anchor: &deep\n")
-	indent := "  "
-	for i := 0; i < MaxYAMLDepth+5; i++ {
-		sb.WriteString(indent)
-		sb.WriteString(fmt.Sprintf("level%d:\n", i))
-		indent += "  "
-	}
-	sb.WriteString(indent + "leaf: value\n")
-	sb.WriteString("target:\n  <<: *deep\n")
-
-	_, err = ParsePersonaBytes([]byte(sb.String()), "deep-merge.yaml")
-	if err == nil {
-		t.Fatal("expected error for deeply nested merge key content, got nil")
-	}
-	if !strings.Contains(err.Error(), "depth") {
-		t.Errorf("error = %q, want to contain 'depth'", err.Error())
-	}
-}

review/repo_persona.go

@@ -4,32 +4,19 @@ import (
 	"context"
 	"log/slog"
 	"strings"
+
+	"gitea.weiker.me/rodin/review-bot/vcs"
 )
 
 // RepoPersonaPath is the directory path where repo-specific personas are stored.
 const RepoPersonaPath = ".review-bot/personas"
 
-// GiteaClient defines the subset of gitea.Client methods needed for loading repo personas.
-// This interface allows for easier testing and decouples the review package from gitea.
-type GiteaClient interface {
-	ListContents(ctx context.Context, owner, repo, path string) ([]ContentEntry, error)
-	GetFileContent(ctx context.Context, owner, repo, filepath string) (string, error)
-}
-
-// ContentEntry represents a file or directory entry from the contents API.
-// This mirrors gitea.ContentEntry to avoid import cycles.
-type ContentEntry struct {
-	Name string `json:"name"`
-	Path string `json:"path"`
-	Type string `json:"type"` // "file" or "dir"
-}
-
 // LoadRepoPersonas fetches personas from a repository's .review-bot/personas/ directory.
 // Returns an empty map (not nil) if the directory doesn't exist or is empty.
 // Individual parse failures are logged and skipped; the remaining personas are still returned.
 // Auth errors and other non-404 errors are propagated.
 // Files exceeding MaxPersonaFileSize are rejected to prevent resource exhaustion.
-func LoadRepoPersonas(ctx context.Context, client GiteaClient, owner, repo string) (map[string]*Persona, error) {
+func LoadRepoPersonas(ctx context.Context, client vcs.FileReader, owner, repo string) (map[string]*Persona, error) {
 	result := make(map[string]*Persona)
 
 	entries, err := client.ListContents(ctx, owner, repo, RepoPersonaPath)
@@ -57,7 +44,7 @@ func LoadRepoPersonas(ctx context.Context, client GiteaClient, owner, repo strin
 			continue
 		}
 
-		content, err := client.GetFileContent(ctx, owner, repo, entry.Path)
+		content, err := client.GetFileContent(ctx, owner, repo, entry.Path, "")
 		if err != nil {
 			slog.Warn("could not fetch repo persona file",
 				"file", entry.Path,

review/repo_persona_test.go

@@ -5,6 +5,8 @@ import (
 	"errors"
 	"strings"
 	"testing"
+
+	"gitea.weiker.me/rodin/review-bot/vcs"
 )
 
 func TestParsePersonaBytes(t *testing.T) {
@@ -17,11 +19,7 @@ func TestParsePersonaBytes(t *testing.T) {
 	}{
 		{
 			name: "valid yaml",
-			data: `name: test
+			data: "name: test\nidentity: test identity\nfocus:\n  - testing\n",
-identity: test identity
-focus:
-  - testing
-`,
 			source:   "test.yaml",
 			wantName: "test",
 		},
@@ -67,15 +65,15 @@ focus:
 	}
 }
 
-// mockGiteaClient implements GiteaClient for testing.
+// mockGiteaClient implements vcs.FileReader for testing.
 type mockGiteaClient struct {
-	contents map[string][]ContentEntry // path -> entries
+	contents map[string][]vcs.ContentEntry // path -> entries
 	files    map[string]string             // path -> content
 	listErr  error
 	fileErr  map[string]error // path -> error
 }
 
-func (m *mockGiteaClient) ListContents(ctx context.Context, owner, repo, path string) ([]ContentEntry, error) {
+func (m *mockGiteaClient) ListContents(ctx context.Context, owner, repo, path string) ([]vcs.ContentEntry, error) {
 	if m.listErr != nil {
 		return nil, m.listErr
 	}
@@ -86,7 +84,7 @@ func (m *mockGiteaClient) ListContents(ctx context.Context, owner, repo, path st
 	return entries, nil
 }
 
-func (m *mockGiteaClient) GetFileContent(ctx context.Context, owner, repo, filepath string) (string, error) {
+func (m *mockGiteaClient) GetFileContent(ctx context.Context, owner, repo, filepath, ref string) (string, error) {
 	if m.fileErr != nil {
 		if err, ok := m.fileErr[filepath]; ok {
 			return "", err
@@ -118,7 +116,7 @@ func TestLoadRepoPersonas(t *testing.T) {
 
 	t.Run("empty directory returns empty map", func(t *testing.T) {
 		client := &mockGiteaClient{
-			contents: map[string][]ContentEntry{
+			contents: map[string][]vcs.ContentEntry{
 				RepoPersonaPath: {},
 			},
 		}
@@ -133,27 +131,15 @@ func TestLoadRepoPersonas(t *testing.T) {
 
 	t.Run("loads valid personas", func(t *testing.T) {
 		client := &mockGiteaClient{
-			contents: map[string][]ContentEntry{
+			contents: map[string][]vcs.ContentEntry{
 				RepoPersonaPath: {
 					{Name: "trading.yaml", Path: ".review-bot/personas/trading.yaml", Type: "file"},
 					{Name: "crypto.yaml", Path: ".review-bot/personas/crypto.yaml", Type: "file"},
 				},
 			},
 			files: map[string]string{
-				".review-bot/personas/trading.yaml": `name: trading
+				".review-bot/personas/trading.yaml": "name: trading\ndisplay_name: Trading Expert\nidentity: You are a trading expert.\nfocus:\n  - order handling\n  - risk management\n",
-display_name: Trading Expert
+				".review-bot/personas/crypto.yaml":  "name: crypto\ndisplay_name: Crypto Expert\nidentity: You are a cryptography expert.\nfocus:\n  - key management\n  - encryption\n",
-identity: You are a trading expert.
-focus:
-  - order handling
-  - risk management
-`,
-				".review-bot/personas/crypto.yaml": `name: crypto
-display_name: Crypto Expert
-identity: You are a cryptography expert.
-focus:
-  - key management
-  - encryption
-`,
 			},
 		}
 		personas, err := LoadRepoPersonas(ctx, client, "owner", "repo")
@@ -176,16 +162,14 @@ focus:
 
 	t.Run("skips invalid persona files", func(t *testing.T) {
 		client := &mockGiteaClient{
-			contents: map[string][]ContentEntry{
+			contents: map[string][]vcs.ContentEntry{
 				RepoPersonaPath: {
 					{Name: "valid.yaml", Path: ".review-bot/personas/valid.yaml", Type: "file"},
 					{Name: "invalid.yaml", Path: ".review-bot/personas/invalid.yaml", Type: "file"},
 				},
 			},
 			files: map[string]string{
-				".review-bot/personas/valid.yaml": `name: valid
+				".review-bot/personas/valid.yaml":   "name: valid\nidentity: Valid persona\n",
-identity: Valid persona
-`,
 				".review-bot/personas/invalid.yaml": "not valid yaml: [broken",
 			},
 		}
@@ -193,7 +177,6 @@ identity: Valid persona
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
-		// Should have the valid one, skip the invalid
 		if len(personas) != 1 {
 			t.Fatalf("expected 1 persona (skipped invalid), got %d", len(personas))
 		}
@@ -204,7 +187,7 @@ identity: Valid persona
 
 	t.Run("skips non-yaml files", func(t *testing.T) {
 		client := &mockGiteaClient{
-			contents: map[string][]ContentEntry{
+			contents: map[string][]vcs.ContentEntry{
 				RepoPersonaPath: {
 					{Name: "persona.yaml", Path: ".review-bot/personas/persona.yaml", Type: "file"},
 					{Name: "README.md", Path: ".review-bot/personas/README.md", Type: "file"},
@@ -212,9 +195,7 @@ identity: Valid persona
 				},
 			},
 			files: map[string]string{
-				".review-bot/personas/persona.yaml": `name: test
+				".review-bot/personas/persona.yaml": "name: test\nidentity: Test persona\n",
-identity: Test persona
-`,
 				".review-bot/personas/README.md":    "# Personas\n\nPut your personas here.",
 			},
 		}
@@ -229,16 +210,14 @@ identity: Test persona
 
 	t.Run("skips subdirectories", func(t *testing.T) {
 		client := &mockGiteaClient{
-			contents: map[string][]ContentEntry{
+			contents: map[string][]vcs.ContentEntry{
 				RepoPersonaPath: {
 					{Name: "persona.yaml", Path: ".review-bot/personas/persona.yaml", Type: "file"},
 					{Name: "subdir", Path: ".review-bot/personas/subdir", Type: "dir"},
 				},
 			},
 			files: map[string]string{
-				".review-bot/personas/persona.yaml": `name: test
+				".review-bot/personas/persona.yaml": "name: test\nidentity: Test persona\n",
-identity: Test persona
-`,
 			},
 		}
 		personas, err := LoadRepoPersonas(ctx, client, "owner", "repo")
@@ -265,16 +244,14 @@ identity: Test persona
 
 	t.Run("skips files that fail to fetch", func(t *testing.T) {
 		client := &mockGiteaClient{
-			contents: map[string][]ContentEntry{
+			contents: map[string][]vcs.ContentEntry{
 				RepoPersonaPath: {
 					{Name: "good.yaml", Path: ".review-bot/personas/good.yaml", Type: "file"},
 					{Name: "bad.yaml", Path: ".review-bot/personas/bad.yaml", Type: "file"},
 				},
 			},
 			files: map[string]string{
-				".review-bot/personas/good.yaml": `name: good
+				".review-bot/personas/good.yaml": "name: good\nidentity: Good persona\n",
-identity: Good persona
-`,
 			},
 			fileErr: map[string]error{
 				".review-bot/personas/bad.yaml": errors.New("HTTP 500: internal server error"),
@@ -290,19 +267,16 @@ identity: Good persona
 	})
 
 	t.Run("skips oversized files", func(t *testing.T) {
-		// Create a content string that exceeds MaxPersonaFileSize (64KB)
 		oversizedContent := strings.Repeat("a", MaxPersonaFileSize+1)
 		client := &mockGiteaClient{
-			contents: map[string][]ContentEntry{
+			contents: map[string][]vcs.ContentEntry{
 				RepoPersonaPath: {
 					{Name: "normal.yaml", Path: ".review-bot/personas/normal.yaml", Type: "file"},
 					{Name: "huge.yaml", Path: ".review-bot/personas/huge.yaml", Type: "file"},
 				},
 			},
 			files: map[string]string{
-				".review-bot/personas/normal.yaml": `name: normal
+				".review-bot/personas/normal.yaml": "name: normal\nidentity: Normal sized persona\n",
-identity: Normal sized persona
-`,
 				".review-bot/personas/huge.yaml":   oversizedContent,
 			},
 		}
@@ -310,7 +284,6 @@ identity: Normal sized persona
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
-		// Should have the normal one, skip the oversized
 		if len(personas) != 1 {
 			t.Fatalf("expected 1 persona (skipped oversized), got %d", len(personas))
 		}
@@ -370,7 +343,6 @@ func TestGetBuiltinPersonasMap(t *testing.T) {
 		t.Fatal("expected at least one built-in persona")
 	}
 
-	// Verify expected personas exist
 	expected := []string{"security", "architect", "docs"}
 	for _, name := range expected {
 		if personas[name] == nil {
@@ -378,7 +350,6 @@ func TestGetBuiltinPersonasMap(t *testing.T) {
 		}
 	}
 
-	// Verify personas are valid
 	for name, p := range personas {
 		if p.Name != name {
 			t.Errorf("persona %q has mismatched name %q", name, p.Name)
@@ -422,8 +393,6 @@ func TestIsNotFoundError(t *testing.T) {
 		{nil, false},
 		{errors.New("HTTP 404: not found"), true},
 		{errors.New("HTTP 404"), true},
-		// Intentionally false: generic "not found" could mask auth/transport errors.
-		// Only explicit HTTP 404 responses should be treated as "directory doesn't exist".
 		{errors.New("something not found"), false},
 		{errors.New("HTTP 401: unauthorized"), false},
 		{errors.New("connection refused"), false},

vcs/check_test.go

@@ -0,0 +1,11 @@
+package vcs_test
+
+import (
+	"gitea.weiker.me/rodin/review-bot/gitea"
+	"gitea.weiker.me/rodin/review-bot/vcs"
+)
+
+// Compile-time assertion: the gitea.Adapter satisfies vcs.Client.
+// (The raw gitea.Client does NOT satisfy vcs.Client due to signature differences;
+// the Adapter bridges them.)
+var _ vcs.Client = (*gitea.Adapter)(nil)

vcs/interfaces.go

@@ -0,0 +1,43 @@
+// Package vcs defines the shared VCS client interface and supporting types.
+// Platform adapters (gitea, github) implement these interfaces so the core
+// review logic can work with any VCS platform without platform-specific code.
+package vcs
+
+import "context"
+
+// PRReader can fetch pull request metadata, diffs, and changed files.
+type PRReader interface {
+	GetPullRequest(ctx context.Context, owner, repo string, number int) (*PullRequest, error)
+	GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error)
+	GetPullRequestFiles(ctx context.Context, owner, repo string, number int) ([]ChangedFile, error)
+	GetFileContentAtRef(ctx context.Context, owner, repo, path, ref string) (string, error)
+	GetCommitStatuses(ctx context.Context, owner, repo, sha string) ([]CommitStatus, error)
+}
+
+// FileReader can fetch file contents and list directory entries.
+type FileReader interface {
+	GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error)
+	ListContents(ctx context.Context, owner, repo, path string) ([]ContentEntry, error)
+}
+
+// Reviewer can post, list, and delete pull request reviews.
+type Reviewer interface {
+	PostReview(ctx context.Context, owner, repo string, number int, req ReviewRequest) (*Review, error)
+	ListReviews(ctx context.Context, owner, repo string, number int) ([]Review, error)
+	DeleteReview(ctx context.Context, owner, repo string, number int, reviewID int64) error
+	DismissReview(ctx context.Context, owner, repo string, number int, reviewID int64, message string) error
+}
+
+// Identity can report who the authenticated user is.
+type Identity interface {
+	GetAuthenticatedUser(ctx context.Context) (string, error)
+}
+
+// Client is the full VCS interface: PR reads, file reads, review management, and identity.
+// Platform adapters (gitea, github) implement this interface.
+type Client interface {
+	PRReader
+	FileReader
+	Reviewer
+	Identity
+}

vcs/types.go

@@ -0,0 +1,98 @@
+package vcs
+
+// ReviewEvent is the event type for a pull request review action.
+// Adapters must translate these action constants to/from platform-native values.
+// For example, Gitea uses "APPROVED" as both action and state, while GitHub
+// uses "APPROVE" for the action and returns "approved" as the state.
+type ReviewEvent string
+
+const (
+	// ReviewEventApprove approves the pull request.
+	ReviewEventApprove ReviewEvent = "APPROVE"
+	// ReviewEventRequestChanges requests changes to the pull request.
+	ReviewEventRequestChanges ReviewEvent = "REQUEST_CHANGES"
+	// ReviewEventComment posts a review comment without approval or rejection.
+	ReviewEventComment ReviewEvent = "COMMENT"
+)
+
+// BaseRef identifies the target branch of a pull request.
+type BaseRef struct {
+	Ref string `json:"ref"`
+}
+
+// HeadRef identifies the source branch and latest commit of a pull request.
+type HeadRef struct {
+	SHA string `json:"sha"`
+	Ref string `json:"ref"`
+}
+
+// UserInfo identifies a user by login name.
+type UserInfo struct {
+	Login string `json:"login"`
+}
+
+// PullRequest holds relevant PR metadata.
+type PullRequest struct {
+	Number int     `json:"number"`
+	Title  string  `json:"title"`
+	Body   string  `json:"body"`
+	Head   HeadRef `json:"head"`
+	Base   BaseRef `json:"base"`
+}
+
+// ChangedFile represents a file modified in a PR.
+type ChangedFile struct {
+	Filename string `json:"filename"`
+	Status   string `json:"status"`
+	Patch    string `json:"patch"`
+}
+
+// ContentEntry represents a file or directory entry from the contents API.
+type ContentEntry struct {
+	Name string `json:"name"`
+	Path string `json:"path"`
+	Type string `json:"type"` // "file" or "dir"
+}
+
+// CommitStatus represents a single CI status entry for a commit.
+type CommitStatus struct {
+	Status      string `json:"status"`
+	Context     string `json:"context"`
+	Description string `json:"description"`
+	TargetURL   string `json:"target_url"`
+}
+
+// Review represents a pull request review.
+type Review struct {
+	ID       int64    `json:"id"`
+	Body     string   `json:"body"`
+	User     UserInfo `json:"user"`
+	State    string   `json:"state"`
+	Stale    bool     `json:"stale"`
+	CommitID string   `json:"commit_id"`
+}
+
+// ReviewComment represents an inline comment in a review.
+// All adapters use GitHub diff-position convention:
+//   - Position is a 1-indexed offset from the @@ hunk line in the unified diff.
+//   - CommitID identifies the commit the comment is anchored to.
+//     It is optional; omit (empty string) for review-level comments that are
+//     not attached to a specific commit.
+//
+// Adapters are responsible for translating to/from platform-native formats
+// (e.g. Gitea uses line numbers; GitHub uses diff positions natively).
+type ReviewComment struct {
+	Path     string `json:"path"`
+	Position int    `json:"position"` // diff-position: 1-indexed offset from @@ hunk line
+	CommitID string `json:"commit_id"`
+	Body     string `json:"body"`
+}
+
+// ReviewRequest is the payload for posting a review.
+type ReviewRequest struct {
+	// Body is the top-level review comment.
+	Body string `json:"body"`
+	// Event is the review action (approve, request changes, or comment).
+	Event    ReviewEvent     `json:"event"`
+	Comments []ReviewComment `json:"comments,omitempty"`
+}

vcs/util.go

@@ -0,0 +1,193 @@
+package vcs
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+const (
+	// maxFilesInPath is the maximum number of files GetAllFilesInPath will fetch.
+	// Prevents unbounded resource consumption on very large directory trees.
+	maxFilesInPath = 10000
+
+	// maxTotalBytesInPath is the maximum total bytes GetAllFilesInPath will accumulate.
+	// Prevents memory exhaustion when fetching large repositories.
+	maxTotalBytesInPath = 100 * 1024 * 1024 // 100 MB
+)
+
+// GetAllFilesInPath recursively fetches all file contents under a path using the
+// provided FileReader. Returns a map of filepath -> content for all files found.
+// If the path points to an empty directory, returns an empty map.
+//
+// This function uses fail-fast error handling: any error from ListContents or
+// GetFileContent aborts the entire traversal and returns the error immediately.
+// This differs from gitea.Client.GetAllFilesInPath, which logs errors and continues.
+// The fail-fast contract ensures callers can trust that a nil error means all files
+// were successfully fetched.
+//
+// Resource limits: the traversal is bounded by maxFilesInPath (file count) and
+// maxTotalBytesInPath (total accumulated bytes). The context is checked before each
+// recursive call and file fetch to respect cancellation.
+func GetAllFilesInPath(ctx context.Context, client FileReader, owner, repo, path string) (map[string]string, error) {
+	results := make(map[string]string)
+	totalBytes := 0
+
+	var walk func(string) error
+	walk = func(dir string) error {
+		if err := ctx.Err(); err != nil {
+			return fmt.Errorf("context canceled during traversal: %w", err)
+		}
+
+		entries, err := client.ListContents(ctx, owner, repo, dir)
+		if err != nil {
+			return fmt.Errorf("list contents %q: %w", dir, err)
+		}
+
+		for _, entry := range entries {
+			if err := ctx.Err(); err != nil {
+				return fmt.Errorf("context canceled during traversal: %w", err)
+			}
+
+			switch entry.Type {
+			case "file":
+				if len(results) >= maxFilesInPath {
+					return fmt.Errorf("exceeded max file count (%d) in path %q", maxFilesInPath, path)
+				}
+
+				content, err := client.GetFileContent(ctx, owner, repo, entry.Path, "")
+				if err != nil {
+					return fmt.Errorf("get file %q: %w", entry.Path, err)
+				}
+
+				totalBytes += len(content)
+				if totalBytes > maxTotalBytesInPath {
+					return fmt.Errorf("exceeded max total bytes (%d) in path %q", maxTotalBytesInPath, path)
+				}
+
+				results[entry.Path] = content
+			case "dir":
+				if err := walk(entry.Path); err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	}
+
+	if err := walk(path); err != nil {
+		return nil, err
+	}
+	return results, nil
+}
+
+// BuildLineToPositionMap parses a unified diff and returns a map of
+// filename -> (new line number -> diff position). The diff position is a
+// 1-indexed offset from the @@ hunk header line for each file.
+// Only lines that appear in the new file (context lines and additions) are mapped.
+// Deletion-only lines are not included.
+func BuildLineToPositionMap(diff string) map[string]map[int]int {
+	result := make(map[string]map[int]int)
+
+	lines := strings.Split(diff, "\n")
+	var currentFile string
+	var position int
+	var newLine int
+
+	for _, line := range lines {
+		// Detect new file in diff
+		if strings.HasPrefix(line, "+++ b/") {
+			currentFile = strings.TrimPrefix(line, "+++ b/")
+			position = 0
+			newLine = 0
+			if result[currentFile] == nil {
+				result[currentFile] = make(map[int]int)
+			}
+			continue
+		}
+
+		// Skip --- lines (old file header)
+		if strings.HasPrefix(line, "--- ") {
+			continue
+		}
+
+		// Skip diff --git lines
+		if strings.HasPrefix(line, "diff --git") {
+			continue
+		}
+
+		// Skip index lines
+		if strings.HasPrefix(line, "index ") {
+			continue
+		}
+
+		// Parse hunk headers
+		if strings.HasPrefix(line, "@@") {
+			position++
+			// Extract new file start line from @@ -a,b +c,d @@
+			newLine = parseHunkNewStart(line)
+			continue
+		}
+
+		// We need a current file to map lines
+		if currentFile == "" {
+			continue
+		}
+
+		// Skip "\ No newline at end of file" markers — these are git diff
+		// metadata and not part of the file content.
+		if strings.HasPrefix(line, `\`) {
+			continue
+		}
+
+		// Process diff content lines
+		if strings.HasPrefix(line, "+") {
+			position++
+			result[currentFile][newLine] = position
+			newLine++
+		} else if strings.HasPrefix(line, "-") {
+			position++
+			// Deletion lines don't map to new line numbers
+		} else if strings.HasPrefix(line, " ") {
+			// Context line (space-prefixed).
+			// Only map if position > 0, which means we've seen a hunk header.
+			// Lines before the first hunk header (position == 0) are not part
+			// of any diff hunk and should be skipped.
+			if position > 0 {
+				position++
+				result[currentFile][newLine] = position
+				newLine++
+			}
+		}
+	}
+
+	return result
+}
+
+// parseHunkNewStart extracts the new-file starting line number from a hunk header.
+// Format: @@ -old_start[,old_count] +new_start[,new_count] @@
+func parseHunkNewStart(hunkLine string) int {
+	// Find the +N part
+	plusIdx := strings.Index(hunkLine, "+")
+	if plusIdx < 0 {
+		return 1
+	}
+	rest := hunkLine[plusIdx+1:]
+
+	// Find the end of the number (first non-digit after +)
+	endIdx := 0
+	for endIdx < len(rest) && rest[endIdx] >= '0' && rest[endIdx] <= '9' {
+		endIdx++
+	}
+
+	if endIdx == 0 {
+		return 1
+	}
+
+	n, err := strconv.Atoi(rest[:endIdx])
+	if err != nil {
+		return 1
+	}
+	return n
+}

vcs/util_test.go

@@ -0,0 +1,331 @@
+package vcs_test
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"testing"
+
+	"gitea.weiker.me/rodin/review-bot/vcs"
+)
+
+// mockFileReader implements vcs.FileReader for testing.
+type mockFileReader struct {
+	contents map[string][]vcs.ContentEntry // path -> entries
+	files    map[string]string             // path -> content
+}
+
+func (m *mockFileReader) GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error) {
+	content, ok := m.files[path]
+	if !ok {
+		return "", fmt.Errorf("HTTP 404: file not found: %s", path)
+	}
+	return content, nil
+}
+
+func (m *mockFileReader) ListContents(ctx context.Context, owner, repo, path string) ([]vcs.ContentEntry, error) {
+	entries, ok := m.contents[path]
+	if !ok {
+		return nil, fmt.Errorf("HTTP 404: path not found: %s", path)
+	}
+	return entries, nil
+}
+
+func TestGetAllFilesInPath(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("empty directory", func(t *testing.T) {
+		client := &mockFileReader{
+			contents: map[string][]vcs.ContentEntry{
+				"src": {},
+			},
+		}
+		result, err := vcs.GetAllFilesInPath(ctx, client, "owner", "repo", "src")
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if len(result) != 0 {
+			t.Errorf("expected empty map, got %d entries", len(result))
+		}
+	})
+
+	t.Run("flat directory", func(t *testing.T) {
+		client := &mockFileReader{
+			contents: map[string][]vcs.ContentEntry{
+				"src": {
+					{Name: "main.go", Path: "src/main.go", Type: "file"},
+					{Name: "util.go", Path: "src/util.go", Type: "file"},
+				},
+			},
+			files: map[string]string{
+				"src/main.go": "package main",
+				"src/util.go": "package main\n// util",
+			},
+		}
+		result, err := vcs.GetAllFilesInPath(ctx, client, "owner", "repo", "src")
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if len(result) != 2 {
+			t.Fatalf("expected 2 files, got %d", len(result))
+		}
+		if result["src/main.go"] != "package main" {
+			t.Errorf("main.go content = %q", result["src/main.go"])
+		}
+		if result["src/util.go"] != "package main\n// util" {
+			t.Errorf("util.go content = %q", result["src/util.go"])
+		}
+	})
+
+	t.Run("nested directories", func(t *testing.T) {
+		client := &mockFileReader{
+			contents: map[string][]vcs.ContentEntry{
+				"src": {
+					{Name: "main.go", Path: "src/main.go", Type: "file"},
+					{Name: "pkg", Path: "src/pkg", Type: "dir"},
+				},
+				"src/pkg": {
+					{Name: "lib.go", Path: "src/pkg/lib.go", Type: "file"},
+					{Name: "sub", Path: "src/pkg/sub", Type: "dir"},
+				},
+				"src/pkg/sub": {
+					{Name: "deep.go", Path: "src/pkg/sub/deep.go", Type: "file"},
+				},
+			},
+			files: map[string]string{
+				"src/main.go":         "package main",
+				"src/pkg/lib.go":      "package pkg",
+				"src/pkg/sub/deep.go": "package sub",
+			},
+		}
+		result, err := vcs.GetAllFilesInPath(ctx, client, "owner", "repo", "src")
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if len(result) != 3 {
+			t.Fatalf("expected 3 files, got %d", len(result))
+		}
+		if result["src/main.go"] != "package main" {
+			t.Errorf("main.go content = %q", result["src/main.go"])
+		}
+		if result["src/pkg/lib.go"] != "package pkg" {
+			t.Errorf("lib.go content = %q", result["src/pkg/lib.go"])
+		}
+		if result["src/pkg/sub/deep.go"] != "package sub" {
+			t.Errorf("deep.go content = %q", result["src/pkg/sub/deep.go"])
+		}
+	})
+
+	t.Run("mixed files and dirs", func(t *testing.T) {
+		client := &mockFileReader{
+			contents: map[string][]vcs.ContentEntry{
+				"root": {
+					{Name: "README.md", Path: "root/README.md", Type: "file"},
+					{Name: "docs", Path: "root/docs", Type: "dir"},
+					{Name: "config.yaml", Path: "root/config.yaml", Type: "file"},
+				},
+				"root/docs": {
+					{Name: "guide.md", Path: "root/docs/guide.md", Type: "file"},
+				},
+			},
+			files: map[string]string{
+				"root/README.md":     "# Hello",
+				"root/config.yaml":   "key: value",
+				"root/docs/guide.md": "## Guide",
+			},
+		}
+		result, err := vcs.GetAllFilesInPath(ctx, client, "owner", "repo", "root")
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if len(result) != 3 {
+			t.Fatalf("expected 3 files, got %d", len(result))
+		}
+		if result["root/README.md"] != "# Hello" {
+			t.Errorf("README content = %q", result["root/README.md"])
+		}
+		if result["root/docs/guide.md"] != "## Guide" {
+			t.Errorf("guide content = %q", result["root/docs/guide.md"])
+		}
+	})
+}
+
+func TestBuildLineToPositionMap(t *testing.T) {
+	t.Run("single hunk", func(t *testing.T) {
+		diff := "diff --git a/file.go b/file.go\nindex abc..def 100644\n--- a/file.go\n+++ b/file.go\n@@ -1,3 +1,4 @@\n package main\n \n+// new comment\n func main() {}\n"
+		result := vcs.BuildLineToPositionMap(diff)
+		fileMap, ok := result["file.go"]
+		if !ok {
+			t.Fatal("expected file.go in result")
+		}
+		// Hunk header @@ is position 1
+		// Line 1: " package main" -> position 2
+		if fileMap[1] != 2 {
+			t.Errorf("line 1 position = %d, want 2", fileMap[1])
+		}
+		// Line 2: " " (context) -> position 3
+		if fileMap[2] != 3 {
+			t.Errorf("line 2 position = %d, want 3", fileMap[2])
+		}
+		// Line 3: "+// new comment" -> position 4
+		if fileMap[3] != 4 {
+			t.Errorf("line 3 position = %d, want 4", fileMap[3])
+		}
+		// Line 4: " func main() {}" -> position 5
+		if fileMap[4] != 5 {
+			t.Errorf("line 4 position = %d, want 5", fileMap[4])
+		}
+	})
+
+	t.Run("multi hunk", func(t *testing.T) {
+		diff := "diff --git a/file.go b/file.go\n--- a/file.go\n+++ b/file.go\n@@ -1,3 +1,3 @@\n package main\n \n-// old\n+// new\n@@ -10,3 +10,4 @@\n func foo() {\n+\t// added\n \treturn\n }\n"
+		result := vcs.BuildLineToPositionMap(diff)
+		fileMap, ok := result["file.go"]
+		if !ok {
+			t.Fatal("expected file.go in result")
+		}
+		// First hunk: @@ is position 1
+		// Line 1: " package main" -> position 2
+		if fileMap[1] != 2 {
+			t.Errorf("line 1 position = %d, want 2", fileMap[1])
+		}
+		// Line 3: "+// new" -> position 5 (after " ", "-// old" at pos 3,4)
+		if fileMap[3] != 5 {
+			t.Errorf("line 3 position = %d, want 5", fileMap[3])
+		}
+		// Second hunk: @@ is position 6
+		// Line 10: " func foo() {" -> position 7
+		if fileMap[10] != 7 {
+			t.Errorf("line 10 position = %d, want 7", fileMap[10])
+		}
+		// Line 11: "+\t// added" -> position 8
+		if fileMap[11] != 8 {
+			t.Errorf("line 11 position = %d, want 8", fileMap[11])
+		}
+	})
+
+	t.Run("deletion lines not in map", func(t *testing.T) {
+		diff := "diff --git a/file.go b/file.go\n--- a/file.go\n+++ b/file.go\n@@ -1,4 +1,3 @@\n package main\n \n-// deleted line\n func main() {}\n"
+		result := vcs.BuildLineToPositionMap(diff)
+		fileMap, ok := result["file.go"]
+		if !ok {
+			t.Fatal("expected file.go in result")
+		}
+		// Line 1: " package main" -> position 2
+		if fileMap[1] != 2 {
+			t.Errorf("line 1 position = %d, want 2", fileMap[1])
+		}
+		// Line 3 in new file: " func main() {}" -> position 5 (after deletion at pos 4)
+		if fileMap[3] != 5 {
+			t.Errorf("line 3 position = %d, want 5", fileMap[3])
+		}
+		// Should only have 3 entries (lines 1, 2, 3 of new file)
+		if len(fileMap) != 3 {
+			t.Errorf("expected 3 mapped lines, got %d: %v", len(fileMap), fileMap)
+		}
+	})
+
+	t.Run("multiple files", func(t *testing.T) {
+		diff := "diff --git a/a.go b/a.go\n--- a/a.go\n+++ b/a.go\n@@ -1,2 +1,3 @@\n package a\n \n+// file a\ndiff --git a/b.go b/b.go\n--- a/b.go\n+++ b/b.go\n@@ -1,2 +1,3 @@\n package b\n \n+// file b\n"
+		result := vcs.BuildLineToPositionMap(diff)
+		if len(result) != 2 {
+			t.Fatalf("expected 2 files, got %d", len(result))
+		}
+		aMap, ok := result["a.go"]
+		if !ok {
+			t.Fatal("expected a.go in result")
+		}
+		bMap, ok := result["b.go"]
+		if !ok {
+			t.Fatal("expected b.go in result")
+		}
+		// a.go line 3: "+// file a" -> position 4
+		if aMap[3] != 4 {
+			t.Errorf("a.go line 3 position = %d, want 4", aMap[3])
+		}
+		// b.go line 3: "+// file b" -> position 4
+		if bMap[3] != 4 {
+			t.Errorf("b.go line 3 position = %d, want 4", bMap[3])
+		}
+	})
+}
+
+func TestGetAllFilesInPath_ErrorPropagation(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("ListContents error propagates", func(t *testing.T) {
+		client := &mockFileReader{
+			contents: map[string][]vcs.ContentEntry{
+				// "src" not in map, so ListContents will fail
+			},
+		}
+		_, err := vcs.GetAllFilesInPath(ctx, client, "owner", "repo", "src")
+		if err == nil {
+			t.Fatal("expected error, got nil")
+		}
+		if !strings.Contains(err.Error(), "list contents") {
+			t.Errorf("expected error about list contents, got: %v", err)
+		}
+	})
+
+	t.Run("GetFileContent error propagates", func(t *testing.T) {
+		client := &mockFileReader{
+			contents: map[string][]vcs.ContentEntry{
+				"src": {
+					{Name: "main.go", Path: "src/main.go", Type: "file"},
+				},
+			},
+			files: map[string]string{
+				// "src/main.go" not in files map, so GetFileContent will fail
+			},
+		}
+		_, err := vcs.GetAllFilesInPath(ctx, client, "owner", "repo", "src")
+		if err == nil {
+			t.Fatal("expected error, got nil")
+		}
+		if !strings.Contains(err.Error(), "get file") {
+			t.Errorf("expected error about get file, got: %v", err)
+		}
+	})
+
+	t.Run("nested ListContents error propagates", func(t *testing.T) {
+		client := &mockFileReader{
+			contents: map[string][]vcs.ContentEntry{
+				"src": {
+					{Name: "pkg", Path: "src/pkg", Type: "dir"},
+				},
+				// "src/pkg" not in map, so recursive ListContents will fail
+			},
+		}
+		_, err := vcs.GetAllFilesInPath(ctx, client, "owner", "repo", "src")
+		if err == nil {
+			t.Fatal("expected error, got nil")
+		}
+		if !strings.Contains(err.Error(), "list contents") {
+			t.Errorf("expected error about list contents, got: %v", err)
+		}
+	})
+
+	t.Run("canceled context propagates", func(t *testing.T) {
+		ctx, cancel := context.WithCancel(context.Background())
+		cancel() // Cancel immediately
+
+		client := &mockFileReader{
+			contents: map[string][]vcs.ContentEntry{
+				"src": {
+					{Name: "main.go", Path: "src/main.go", Type: "file"},
+				},
+			},
+			files: map[string]string{
+				"src/main.go": "package main",
+			},
+		}
+		_, err := vcs.GetAllFilesInPath(ctx, client, "owner", "repo", "src")
+		if err == nil {
+			t.Fatal("expected error from canceled context, got nil")
+		}
+		if !strings.Contains(err.Error(), "context canceled") {
+			t.Errorf("expected context cancellation error, got: %v", err)
+		}
+	})
+}