name: Pre-commit failure comment
on:
  workflow_run:
    workflows: ["Checks"]
    types: [completed]

permissions:
  pull-requests: write

jobs:
  comment:
    if: github.event.workflow_run.event == 'pull_request'
    runs-on: ubuntu-latest
    steps:
      - name: Post comment if pre-commit failed
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const { owner, repo } = context.repo;
            const run = context.payload.workflow_run;

            if (run.conclusion !== 'failure') return;

            const { data: { jobs } } = await github.rest.actions.listJobsForWorkflowRun({
              owner, repo, run_id: run.id,
            });
            const preCommitJob = jobs.find(j => j.name === 'pre-commit');
            if (!preCommitJob || preCommitJob.conclusion !== 'failure') return;

            // For fork PRs, pull_requests is empty; find by head owner:branch.
            let prNumber;
            if (run.pull_requests.length > 0) {
              prNumber = run.pull_requests[0].number;
            } else {
              const head = `${run.head_repository.owner.login}:${run.head_branch}`;
              const { data: prs } = await github.rest.pulls.list({
                owner, repo, state: 'open', head,
              });
              if (prs.length === 0) return;
              prNumber = prs[0].number;
            }

            // Skip if pre-commit is already mentioned anywhere on the PR.
            const mentions = text => /pre-commit/i.test(text ?? '');

            const { data: pr } = await github.rest.pulls.get({ owner, repo, pull_number: prNumber });
            if (mentions(pr.body)) return;

            const { data: issueComments } = await github.rest.issues.listComments({ owner, repo, issue_number: prNumber });
            if (issueComments.some(c => mentions(c.body))) return;

            const { data: reviewComments } = await github.rest.pulls.listReviewComments({ owner, repo, pull_number: prNumber });
            if (reviewComments.some(c => mentions(c.body))) return;

            const { data: reviews } = await github.rest.pulls.listReviews({ owner, repo, pull_number: prNumber });
            if (reviews.some(r => mentions(r.body))) return;

            await github.rest.issues.createComment({
              owner,
              repo,
              issue_number: prNumber,
              body: 'The pre-commit checks failed on this PR. Please [set up pre-commit](https://doc.scrapy.org/en/latest/contributing.html#scrapy-pre-commit) and run it locally before pushing.',
            });