name: Codex PR Review

on:
  pull_request:
    types:
      - opened
      - synchronize
      - reopened
      - ready_for_review

jobs:
  codex:
    if: github.event.pull_request.draft == false
    runs-on: ubuntu-latest
    permissions:
      contents: read
    outputs:
      final_message: ${{ steps.run_codex.outputs.final-message }}
    steps:
      - uses: actions/checkout@v5
        with:
          ref: refs/pull/${{ github.event.pull_request.number }}/merge

      - name: Pre-fetch base and head refs for the PR
        run: |
          git fetch --no-tags origin \
            ${{ github.event.pull_request.base.ref }} \
            +refs/pull/${{ github.event.pull_request.number }}/head

      - name: Run Codex review
        id: run_codex
        uses: openai/codex-action@v1
        with:
          openai-api-key: ${{ secrets.CODEX_API_KEY }}
          responses-api-endpoint: ${{ secrets.CODEX_RESPONSES_API_ENDPOINT }}
          prompt: |
            This is PR #${{ github.event.pull_request.number }} for ${{ github.repository }}.

            Review only changes from this PR using:
              git log --oneline ${{ github.event.pull_request.base.sha }}...${{ github.event.pull_request.head.sha }}

            Focus on:
            - bugs and regressions
            - security issues
            - risky edge cases
            - missing tests where critical

            Keep feedback concise and actionable.

            Pull request title and body:
            ----
            ${{ github.event.pull_request.title }}
            ${{ github.event.pull_request.body }}

  post-feedback:
    runs-on: ubuntu-latest
    needs: codex
    if: needs.codex.outputs.final_message != ''
    permissions:
      issues: write
      pull-requests: write
    steps:
      - name: Post Codex feedback to PR
        uses: actions/github-script@v7
        env:
          CODEX_FINAL_MESSAGE: ${{ needs.codex.outputs.final_message }}
        with:
          github-token: ${{ github.token }}
          script: |
            await github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.payload.pull_request.number,
              body: process.env.CODEX_FINAL_MESSAGE,
            });