feat: add context.Context + unexport client fields

REVIEW.md findings 1-4, 14:
- All Gitea client methods now accept context.Context as first param
- All LLM client methods now accept context.Context as first param
- Use http.NewRequestWithContext for cancellation/timeout support
- Main uses 3-minute timeout context for all operations
- Unexport Client struct fields (baseURL, token, apiKey, etc.)
- Use bytes.NewReader instead of strings.NewReader(string(...))

cmd/review-bot/main.go

@@ -1,12 +1,14 @@
 package main
 
 import (
+	"context"
 	"flag"
 	"fmt"
 	"log"
 	"os"
 	"strconv"
 	"strings"
+	"time"
 
 	"gitea.weiker.me/rodin/review-bot/gitea"
 	"gitea.weiker.me/rodin/review-bot/llm"
@@ -64,17 +66,21 @@ func main() {
 		llmClient.WithTemperature(*llmTemp)
 	}
 
+	// Create a top-level context with a 3-minute timeout for all operations
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Minute)
+	defer cancel()
+
 	log.Printf("Reviewing PR #%d on %s/%s", prNumber, owner, repoName)
 
 	// Step 1: Fetch PR metadata
-	pr, err := giteaClient.GetPullRequest(owner, repoName, prNumber)
+	pr, err := giteaClient.GetPullRequest(ctx, owner, repoName, prNumber)
 	if err != nil {
 		log.Fatalf("Failed to fetch PR: %v", err)
 	}
 	log.Printf("PR: %s", pr.Title)
 
 	// Step 2: Fetch diff
-	diff, err := giteaClient.GetPullRequestDiff(owner, repoName, prNumber)
+	diff, err := giteaClient.GetPullRequestDiff(ctx, owner, repoName, prNumber)
 	if err != nil {
 		log.Fatalf("Failed to fetch diff: %v", err)
 	}
@@ -82,11 +88,11 @@ func main() {
 
 	// Step 3: Fetch full file content for modified files
 	fileContext := ""
-	files, err := giteaClient.GetPullRequestFiles(owner, repoName, prNumber)
+	files, err := giteaClient.GetPullRequestFiles(ctx, owner, repoName, prNumber)
 	if err != nil {
 		log.Printf("Warning: could not fetch PR files list: %v", err)
 	} else {
-		fileContext = fetchFileContext(giteaClient, owner, repoName, pr.Head.Ref, files)
+		fileContext = fetchFileContext(ctx, giteaClient, owner, repoName, pr.Head.Ref, files)
 		log.Printf("Fetched full context for %d files", len(files))
 	}
 
@@ -94,7 +100,7 @@ func main() {
 	ciPassed := true
 	ciDetails := ""
 	if pr.Head.Sha != "" {
-		statuses, err := giteaClient.GetCommitStatuses(owner, repoName, pr.Head.Sha)
+		statuses, err := giteaClient.GetCommitStatuses(ctx, owner, repoName, pr.Head.Sha)
 		if err != nil {
 			log.Printf("Warning: could not fetch CI status: %v", err)
 		} else {
@@ -106,7 +112,7 @@ func main() {
 	// Step 5: Load conventions file if specified
 	conventions := ""
 	if *conventionsFile != "" {
-		content, err := giteaClient.GetFileContent(owner, repoName, *conventionsFile)
+		content, err := giteaClient.GetFileContent(ctx, owner, repoName, *conventionsFile)
 		if err != nil {
 			log.Printf("Warning: could not load conventions file %q: %v", *conventionsFile, err)
 		} else {
@@ -118,7 +124,7 @@ func main() {
 	// Step 6: Load patterns from external repo if specified
 	patterns := ""
 	if *patternsRepo != "" {
-		patterns = fetchPatterns(giteaClient, *patternsRepo, *patternsFiles)
+		patterns = fetchPatterns(ctx, giteaClient, *patternsRepo, *patternsFiles)
 		log.Printf("Loaded patterns from %s (%d bytes)", *patternsRepo, len(patterns))
 	}
 
@@ -133,7 +139,7 @@ func main() {
 		{Role: "user", Content: userPrompt},
 	}
 
-	response, err := llmClient.Complete(messages)
+	response, err := llmClient.Complete(ctx, messages)
 	if err != nil {
 		log.Fatalf("LLM request failed: %v", err)
 	}
@@ -158,20 +164,20 @@ func main() {
 	}
 
 	log.Printf("Posting review (event=%s)...", event)
-	if err := giteaClient.PostReview(owner, repoName, prNumber, event, reviewBody); err != nil {
+	if err := giteaClient.PostReview(ctx, owner, repoName, prNumber, event, reviewBody); err != nil {
 		log.Fatalf("Failed to post review: %v", err)
 	}
 	log.Printf("Review posted successfully!")
 }
 
 // fetchFileContext fetches the full content of modified files from the PR branch.
-func fetchFileContext(client *gitea.Client, owner, repo, ref string, files []gitea.ChangedFile) string {
+func fetchFileContext(ctx context.Context, client *gitea.Client, owner, repo, ref string, files []gitea.ChangedFile) string {
 	var sb strings.Builder
 	for _, f := range files {
 		if f.Status == "removed" {
 			continue // Skip deleted files
 		}
-		content, err := client.GetFileContentRef(owner, repo, f.Filename, ref)
+		content, err := client.GetFileContentRef(ctx, owner, repo, f.Filename, ref)
 		if err != nil {
 			log.Printf("Warning: could not fetch %s: %v", f.Filename, err)
 			continue
@@ -188,7 +194,7 @@ func fetchFileContext(client *gitea.Client, owner, repo, ref string, files []git
 // 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.
-func fetchPatterns(client *gitea.Client, patternsRepo, patternsFiles string) string {
+func fetchPatterns(ctx context.Context, client *gitea.Client, patternsRepo, patternsFiles string) string {
 	var sb strings.Builder
 
 	repos := strings.Split(patternsRepo, ",")
@@ -212,7 +218,7 @@ func fetchPatterns(client *gitea.Client, patternsRepo, patternsFiles string) str
 				continue
 			}
 
-			files, err := client.GetAllFilesInPath(owner, repo, path)
+			files, err := client.GetAllFilesInPath(ctx, owner, repo, path)
 			if err != nil {
 				log.Printf("Warning: could not fetch %s from %s: %v", path, repoRef, err)
 				continue