name: PR Checklist Validation (History Rewrite)

on:
  pull_request:
    types: [opened, edited, synchronize]

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

jobs:
  validate:
    name: Validate history-rewrite checklist (conditional)
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6

      - name: Validate PR checklist (only for history-rewrite changes)
        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
        with:
          script: |
            const owner = context.repo.owner;
            const repo = context.repo.repo;
            const prNumber = context.issue.number;
            const pr = await github.rest.pulls.get({owner, repo, pull_number: prNumber});
            const body = (pr.data && pr.data.body) || '';

            // Determine if this PR modifies history-rewrite related files
            // Exclude the template file itself - it shouldn't trigger its own validation
            const filesResp = await github.rest.pulls.listFiles({ owner, repo, pull_number: prNumber });
            const files = filesResp.data.map(f => f.filename.toLowerCase());
            const relevant = files.some(fn => {
              // Skip the PR template itself
              if (fn === '.github/pull_request_template/history-rewrite.md') return false;
              // Check for actual history-rewrite implementation files
              return fn.startsWith('scripts/history-rewrite/') || fn === 'docs/plans/history_rewrite.md';
            });
            if (!relevant) {
              core.info('No history-rewrite related files changed; skipping checklist validation.');
              return;
            }

            // Use a set of named checks with robust regex patterns for checkbox and phrase variants
            const checks = [
              { name: 'preview_removals.sh mention', pattern: /preview_removals\.sh/i },
              { name: 'data/backups mention', pattern: /data\/?backups/i },
              // Accept checked checkbox variants and inline code/backtick usage for the '--force' phrase
              { name: 'explicit non-run of --force', pattern: /(?:\[\s*[xX]\s*\]\s*)?(?:i will not run|will not run|do not run|don'?t run|won'?t run)\b[^\n]*--force/i },
            ];

            const missing = checks.filter(c => !c.pattern.test(body)).map(c => c.name);
            if (missing.length > 0) {
              // Post a comment to the PR with instructions for filling the checklist
              const commentBody = `Hi! This PR touches history-rewrite artifacts and requires the checklist in .github/PULL_REQUEST_TEMPLATE/history-rewrite.md. The following items are missing in your PR body: ${missing.join(', ')}\n\nPlease update the PR description using the history-rewrite template and re-run checks.`;
              await github.rest.issues.createComment({ owner, repo, issue_number: prNumber, body: commentBody });
              core.setFailed('Missing required checklist items: ' + missing.join(', '));
            }