gemini-cli-review.yml

name: Gemini CLI PR Review
on:
  pull_request:
    types: [opened, synchronize, ready_for_review]

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
  cancel-in-progress: true

run-name: Gemini review for PR ${{ github.event.pull_request.number }} - ${{ github.event.pull_request.head.sha }}

jobs:
  gemini-pr-review:
    # Temporarily disabled to avoid burning API tokens
    if: false
    # Skip if PR is in draft
    # if: github.event.pull_request.draft == false
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
    env:
      GEMINI_OUTPUT_DIR: artifacts/gemini_review/${{ github.event.pull_request.number }}-${{ github.event.pull_request.head.sha }}
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
      
      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'
      
      - name: Install Gemini CLI
        shell: bash
        run: |
          npm install -g @google/gemini-cli@latest
          echo "$(npm config get prefix)/bin" >> $GITHUB_PATH

      - name: Verify Gemini CLI
        shell: bash
        run: |
          which gemini
          gemini --version

      - name: Set up Python
        uses: actions/setup-python@v4
        with:
          python-version: '3.10'

      - name: Install/Upgrade Google Python Client
        shell: bash
        run: |
          python -m pip install --upgrade pip
          pip install --upgrade google-generativeai
          # If you have a requirements.txt file, you might use this instead:
          # pip install -r requirements.txt --upgrade

      - name: Run Gemini PR review
        env:
          #GEMINI_MODEL: gemini-1.5-flash-latest
          GEMINI_API_KEY: ${{ secrets.GEMINI_TEST }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
          PR_SHA: ${{ github.event.pull_request.head.sha }}
          PR_BASE_SHA: ${{ github.event.pull_request.base.sha }}
          PR_BASE_REF: ${{ github.event.pull_request.base.ref }}
          PR_HEAD_SHA: ${{ github.event.pull_request.head.sha }}
          PR_HEAD_REF: ${{ github.event.pull_request.head.ref }}
        run: |
          python -m tools.pr_preflight_launcher --ai-backend gemini --output-dir "${GEMINI_OUTPUT_DIR}"

      - name: Print Gemini error (if any)
        if: always()
        run: |
          if [ -f "${{ env.GEMINI_OUTPUT_DIR }}/error.txt" ]; then
            echo "===== Gemini error.txt ====="
            sed -n '1,200p' "${{ env.GEMINI_OUTPUT_DIR }}/error.txt"
          else
            echo "No error.txt found in ${{ env.GEMINI_OUTPUT_DIR }}"
          fi

      - name: Post Gemini review to PR
        if: always()
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const fs = require('fs');
            const path = require('path');

            const outputDir = process.env.GEMINI_OUTPUT_DIR;
            const commentMarker = '<!-- gemini-pr-review-bot -->';

            // Check if review failed or errored - if so, don't post comment
            const errorFile = path.join(outputDir, 'error.txt');
            const verdictFile = path.join(outputDir, 'review_verdict.txt');
            const successFile = path.join(outputDir, 'success_raw_output.txt');

            // Skip posting if error occurred
            if (fs.existsSync(errorFile)) {
              console.log('Review encountered an error. Skipping comment post.');
              return;
            }

            // Skip posting if review failed
            if (fs.existsSync(verdictFile)) {
              const verdict = fs.readFileSync(verdictFile, 'utf8').trim();
              if (verdict.includes('FAILED')) {
                console.log('Review verdict: FAILED. Skipping comment post.');
                return;
              }
            }

            // Skip if no success output
            if (!fs.existsSync(successFile)) {
              console.log('No review output found. Skipping comment post.');
              return;
            }

            // Read review output
            const reviewContent = fs.readFileSync(successFile, 'utf8');

            // Prepare comment body
            const commentBody = `${commentMarker}
            ## 🤖 Gemini PR Review

            **Commit:** ${context.payload.pull_request.head.sha}

            ${reviewContent}

            ---
            *Review generated at ${new Date().toISOString()}*`;

            // Find existing comment
            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.payload.pull_request.number,
            });

            const existingComment = comments.find(comment =>
              comment.body && comment.body.includes(commentMarker)
            );

            // Create or update comment
            if (existingComment) {
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existingComment.id,
                body: commentBody,
              });
              console.log('Updated existing PR comment');
            } else {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.payload.pull_request.number,
                body: commentBody,
              });
              console.log('Created new PR comment');
            }