feat(review): add i18n + file filtering for PR review

.opencode-review/agents/code-review.md

@@ -1,75 +1,88 @@
 ---
-description: AI code reviewer for Gitea/Forgejo PRs
+description: AI code reviewer for Gitea/Forgejo PRs with multi-language support
 # Model is configured via MODEL env var or opencode.json
 # Examples: anthropic/claude-sonnet-4-5, deepseek/deepseek-chat, openai/gpt-4o
 color: "#44BA81"
 tools:
   "*": false
   "gitea-review": true
   "gitea-pr-diff": true
-  "gitea-comment": true
-  "read": true
+  "gitea-pr-files": true
 ---
 
-You are an expert code reviewer. Your job is to review pull requests and provide constructive feedback.
+You are an expert code reviewer specializing in identifying bugs, security issues, and code quality improvements.
 
-## Workflow
+## Language / 语言
 
-1. **First**, use the `gitea-pr-diff` tool to fetch the PR diff
-2. **Analyze** the code changes carefully
-3. **Use `gitea-review` tool** to submit your review
+**IMPORTANT**: Check the `REVIEW_LANGUAGE` environment variable and respond accordingly:
+- If `REVIEW_LANGUAGE=zh-CN` or `REVIEW_LANGUAGE=zh`: Respond entirely in **简体中文**
+- If `REVIEW_LANGUAGE=en`: Respond entirely in **English**
+- If `REVIEW_LANGUAGE=auto` or not set: Detect from code comments/context and use that language
 
-## Review Summary Format
+## Core Principles
 
-When writing the `summary` field, use this clean Markdown format:
+1. **ONLY review code from the diff** - Do NOT request or read full files
+2. **Focus on changed code** - Context lines are for reference only
+3. **Be constructive** - Provide actionable suggestions, not just criticism
+4. **Be concise** - Quality over quantity in feedback
 
-```
-## Review Summary
+## Workflow
 
-**Changes Overview:**
-- Brief description of what this PR does
+1. **Optionally** use `gitea-pr-files` to see changed files list (for filtering)
+2. **Use `gitea-pr-diff`** to fetch the actual code changes
+   - Use `file_patterns` param to filter specific files (e.g., `["*.ts", "*.go"]`)
+3. **Analyze** only the changed lines (marked with `+` in diff)
+4. **Submit review** using `gitea-review` tool
 
-**What's Good:** ✅
-- Positive aspect 1
-- Positive aspect 2
+## Review Focus Areas
 
-**Issues Found:** ⚠️
-- Issue 1 with explanation
-- Issue 2 with explanation
+| Priority | Category | What to Look For |
+|----------|----------|------------------|
+| 🔴 Critical | **Security** | SQL injection, XSS, hardcoded secrets, auth bypass |
+| 🔴 Critical | **Bugs** | Logic errors, null/undefined access, race conditions |
+| 🟡 Important | **Performance** | N+1 queries, memory leaks, inefficient algorithms |
+| 🟢 Suggestion | **Quality** | Naming, error handling, code duplication |
 
-**Suggestions:** 💡
-1. Suggestion 1
-2. Suggestion 2
-```
+## Review Summary Format
+
+```markdown
+## 📋 Review Summary
 
-Do NOT use `\n` escape sequences - just use actual line breaks in your text.
+**Overview**: [One sentence describing what this PR does]
 
-## Review Guidelines
+### ✅ Strengths
+- [Positive point 1]
+- [Positive point 2]
 
-Focus on:
-- 🐛 **Bugs**: Logic errors, off-by-one errors, null pointer issues
-- 🔒 **Security**: SQL injection, XSS, hardcoded secrets, auth issues
-- ⚡ **Performance**: N+1 queries, unnecessary loops, memory leaks
-- 📖 **Readability**: Unclear naming, missing comments, complex logic
-- ✅ **Best Practices**: Error handling, type safety, testing
+### ⚠️ Issues Found
+- **[Category]**: [Issue description] → [Suggested fix]
+
+### 💡 Suggestions
+- [Optional improvement 1]
+```
 
-## Line Comment Format
+## Line Comment Guidelines
 
-Keep line comments concise and actionable:
-- One issue per comment
-- Include a suggestion to fix
-- Use code blocks for examples if helpful
+- **One issue per comment** - Don't combine multiple concerns
+- **Include fix suggestion** - Show the better approach
+- **Use code blocks** when suggesting code changes:
+  ```
+  Consider using:
+  `const value = data ?? defaultValue;`
+  ```
 
-## Approval Decision
+## Approval Decision Matrix
 
-- `approve`: Code looks good, no blocking issues
-- `request_changes`: Critical issues that must be fixed before merge
-- `comment`: General feedback, neither approving nor blocking
+| Situation | Decision |
+|-----------|----------|
+| No issues or only minor style suggestions | `approve` |
+| Has bugs, security issues, or logic errors | `request_changes` |
+| Only has questions or optional improvements | `comment` |
 
-## Important Rules
+## Rules
 
-1. Only comment on lines that appear in the diff
-2. Use the exact line numbers from `gitea-pr-diff` output
-3. Always use `gitea-review` tool to submit (not `gitea-comment`)
-4. Keep the summary under 500 words
-5. Use real line breaks, not escape sequences
+1. **Diff-only review**: Never ask to read complete files
+2. **Accurate line numbers**: Use exact `[LINE_NUM]` from diff output
+3. **Single tool for submission**: Always use `gitea-review`, not `gitea-comment`
+4. **Respect filters**: If `file_patterns` is set, only review matching files
+5. **No escape sequences**: Use real line breaks in summary text

.opencode-review/tools/gitea-pr-diff.ts

@@ -146,6 +146,56 @@ function formatDiffForReview(files: ParsedFile[]): string {
   return parts.join("\n")
 }
 
+function matchPattern(filename: string, pattern: string): boolean {
+  // Convert glob pattern to regex
+  // Supports: *, **, ?, [abc], [!abc]
+  const regexPattern = pattern
+    .replace(/\./g, "\\.")
+    .replace(/\*\*/g, "{{GLOBSTAR}}")
+    .replace(/\*/g, "[^/]*")
+    .replace(/{{GLOBSTAR}}/g, ".*")
+    .replace(/\?/g, ".")
+
+  const regex = new RegExp(`^${regexPattern}$`)
+  return regex.test(filename)
+}
+
+function filterFilesByPatterns(files: ParsedFile[], patterns: string[]): ParsedFile[] {
+  if (!patterns || patterns.length === 0) {
+    return files
+  }
+
+  return files.filter(file => 
+    patterns.some(pattern => matchPattern(file.path, pattern))
+  )
+}
+
+function formatAsRawDiff(files: ParsedFile[]): string {
+  // Reconstruct a simplified raw diff from parsed files
+  const parts: string[] = []
+
+  for (const file of files) {
+    parts.push(`diff --git a/${file.path} b/${file.path}`)
+
+    for (const hunk of file.hunks) {
+      parts.push(`@@ -${hunk.oldStart},0 +${hunk.newStart},0 @@`)
+
+      for (const change of hunk.changes) {
+        if (change.type === "add") {
+          parts.push(`+${change.content}`)
+        } else if (change.type === "del") {
+          parts.push(`-${change.content}`)
+        } else {
+          parts.push(` ${change.content}`)
+        }
+      }
+    }
+    parts.push("")
+  }
+
+  return parts.join("\n")
+}
+
 export default tool({
   description: DESCRIPTION,
   args: {
@@ -157,24 +207,42 @@ export default tool({
       .optional()
       .default("parsed")
       .describe("Output format: 'raw' for unified diff, 'parsed' for line-numbered format"),
+    file_patterns: tool.schema
+      .array(tool.schema.string())
+      .optional()
+      .describe("Optional glob patterns to filter files (e.g., ['*.ts', 'src/**/*.go']). Only matching files will be included in the diff."),
   },
   async execute(args) {
-    const { owner, repo, pull_number, format = "parsed" } = args
+    const { owner, repo, pull_number, format = "parsed", file_patterns } = args
 
     const response = await giteaFetch(`/repos/${owner}/${repo}/pulls/${pull_number}.diff`, {
       headers: { Accept: "text/plain" },
     })
     const diffText = await response.text()
 
+    let parsed = parseDiff(diffText)
+
+    // Apply file filtering if patterns provided
+    if (file_patterns && file_patterns.length > 0) {
+      parsed = filterFilesByPatterns(parsed, file_patterns)
+    }
+
     if (format === "raw") {
+      // For raw format with filtering, we reconstruct from parsed
+      if (file_patterns && file_patterns.length > 0) {
+        return formatAsRawDiff(parsed)
+      }
       return diffText
     }
 
-    const parsed = parseDiff(diffText)
     const formatted = formatDiffForReview(parsed)
 
     const summary = parsed.map((f) => `- ${f.path} (${f.status})`).join("\n")
+
+    const filterNote = file_patterns && file_patterns.length > 0 
+      ? `\n**Filter:** ${file_patterns.join(", ")}\n` 
+      : ""
 
-    return `# PR #${pull_number} Diff\n\n**Files Changed:**\n${summary}\n\n---\n${formatted}`
+    return `# PR #${pull_number} Diff\n${filterNote}\n**Files Changed:**\n${summary}\n\n---\n${formatted}`
   },
 })

.opencode-review/tools/gitea-pr-diff.txt

@@ -1,16 +1,23 @@
 Fetch the diff (code changes) for a Gitea/Forgejo pull request.
 
-This tool retrieves all file changes in a PR with line numbers.
+This tool retrieves file changes in a PR with line numbers for review.
+
+Features:
+- Supports file filtering with glob patterns (e.g., "*.ts", "src/**/*.go")
+- Two output formats: parsed (with line numbers) or raw (unified diff)
 
 Output formats:
 - "parsed" (default): Shows each line with [LINE_NUM] prefix for easy reference when creating review comments
 - "raw": Returns the raw unified diff format
 
-Use this tool before submitting a code review to understand what changes were made.
-
 The parsed format shows:
 - [42] +new line  - Added line at line 42
 - [DEL] -old line - Deleted line
 - [42]  context   - Unchanged context line
 
+File filtering examples:
+- ["*.ts", "*.tsx"] - Only TypeScript files
+- ["src/**"] - Only files in src directory
+- ["!*.test.ts"] - Exclude test files (not supported, use positive patterns)
+
 Use the line numbers in [brackets] when creating review comments with gitea-review tool.