用 Codex 加速 Code Review：Ramp 工程师的分钟级反馈实践

name: AI Code Review

on:
  pull_request:
    types: [opened, synchronize]

permissions:
  pull-requests: write
  contents: read

jobs:
  review:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Get PR diff
        id: diff
        run: |
          # 获取 PR 相对于 base 分支的 diff
          DIFF=$(git diff origin/${{ github.base_ref }}...HEAD)
          # diff 太长时截断，避免超出 API token 限制
          echo "diff<<EOF" >> $GITHUB_OUTPUT
          echo "$DIFF" | head -c 30000 >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT

      - name: Call OpenAI for review
        id: ai
        env:
          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
        run: |
          python3 .github/scripts/ai_review.py \
            "${{ steps.diff.outputs.diff }}" \
            "${{ github.repository }}" \
            "${{ github.event.pull_request.number }}"

      - name: Comment on PR
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          gh pr comment ${{ github.event.pull_request.number }} \
            --body-file .github/scripts/review_comment.md

#!/usr/bin/env python3
"""调用 OpenAI API 对 PR diff 进行 code review，输出结构化评论。"""

import json
import os
import sys
import urllib.request

API_KEY = os.environ["OPENAI_API_KEY"]
MODEL = "gpt-4o"  # 可替换为 gpt-5.5 等更新模型


def call_openai(diff: str, repo: str, pr_number: int) -> str:
    prompt = f"""你是一位资深工程师，正在审查以下 PR diff。
仓库: {repo}, PR #{pr_number}

请逐段分析 diff，对每个发现的问题：
1. 指出具体文件和行号范围
2. 解释问题原因（安全、性能、逻辑错误、可维护性等）
3. 给出修改建议或改进后的代码片段

如果没有问题，简要说明改动看起来合理的地方。
用中文输出，格式为 Markdown。

Diff:
{diff}
"""

    payload = {
        "model": MODEL,
        "messages": [{"role": "user", "content": prompt}],
        "temperature": 0.2,  # 低温度保证输出稳定
        "max_tokens": 4096,
    }

    req = urllib.request.Request(
        "https://api.openai.com/v1/chat/completions",
        data=json.dumps(payload).encode(),
        headers={
            "Authorization": f"Bearer {API_KEY}",
            "Content-Type": "application/json",
        },
    )

    with urllib.request.urlopen(req) as resp:
        result = json.loads(resp.read())
        return result["choices"][0]["message"]["content"]


def main():
    diff_text = sys.argv[1]
    repo = sys.argv[2]
    pr_number = int(sys.argv[3])

    review = call_openai(diff_text, repo, pr_number)

    # 写入评论文件，供后续 step 使用
    with open(".github/scripts/review_comment.md", "w") as f:
        f.write(f"## 🤖 AI Code Review\n\n{review}\n\n---\n*由 AI 自动生成，仅供参考，最终判断由人类 reviewer 负责。*")


if __name__ == "__main__":
    main()