#!/bin/bash
# Install review-bot from latest Gitea release
# Usage: curl -sSfL https://gitea.weiker.me/rodin/review-bot/raw/branch/main/install.sh | bash

set -euo pipefail

GITEA_URL="${GITEA_URL:-https://gitea.weiker.me}"
REPO="rodin/review-bot"
INSTALL_DIR="${INSTALL_DIR:-}"

# Determine install directory with fallback
if [ -z "$INSTALL_DIR" ]; then
  if [ -w /usr/local/bin ]; then
    INSTALL_DIR="/usr/local/bin"
  else
    INSTALL_DIR="${HOME}/.local/bin"
    mkdir -p "$INSTALL_DIR"
    echo "Note: Installing to $INSTALL_DIR (add to PATH if needed)"
  fi
fi

OS=$(uname -s | tr '[:upper:]' '[:lower:]')
ARCH=$(uname -m)
case "$ARCH" in
  x86_64) ARCH="amd64" ;;
  aarch64|arm64) ARCH="arm64" ;;
  *) echo "Unsupported architecture: $ARCH" >&2; exit 1 ;;
esac

BINARY="review-bot-${OS}-${ARCH}"

# Get latest release tag (POSIX-safe parsing without jq)
LATEST=$(curl -sSf "${GITEA_URL}/api/v1/repos/${REPO}/releases?limit=1" | sed -n 's/.*"tag_name":"\([^"]*\)".*/\1/p' | head -1)

if [ -z "$LATEST" ]; then
  echo "Failed to determine latest release" >&2
  exit 1
fi

echo "Installing review-bot ${LATEST} (${OS}/${ARCH})..."

DOWNLOAD_URL="${GITEA_URL}/${REPO}/releases/download/${LATEST}/${BINARY}"
CHECKSUM_URL="${GITEA_URL}/${REPO}/releases/download/${LATEST}/checksums.txt"

# Download binary and checksums
TMPDIR=$(mktemp -d)
trap 'rm -rf "$TMPDIR"' EXIT

curl -sSfL -o "${TMPDIR}/${BINARY}" "$DOWNLOAD_URL"
curl -sSfL -o "${TMPDIR}/checksums.txt" "$CHECKSUM_URL"

# Verify checksum
cd "$TMPDIR"
EXPECTED=$(grep "${BINARY}" checksums.txt | awk '{print $1}')
ACTUAL=$(sha256sum "${BINARY}" | awk '{print $1}')

if [ -z "$EXPECTED" ]; then
  echo "Error: no checksum found for ${BINARY} in checksums.txt" >&2
  exit 1
fi

if [ "$EXPECTED" != "$ACTUAL" ]; then
  echo "Error: checksum mismatch!" >&2
  echo "  Expected: $EXPECTED" >&2
  echo "  Actual:   $ACTUAL" >&2
  exit 1
fi

echo "Checksum verified ✓"

# Install
cp "${TMPDIR}/${BINARY}" "${INSTALL_DIR}/review-bot"
chmod +x "${INSTALL_DIR}/review-bot"

echo "Installed review-bot ${LATEST} to ${INSTALL_DIR}/review-bot"