name: Awaiting Response Scheduled Scan

on:
  schedule:
    # Runs daily at 02:45 UTC (offset from the 01:30 CLA stale scan).
    - cron: '45 2 * * *'
  workflow_dispatch: {}

permissions:
  pull-requests: write
  issues: write
  contents: read

env:
  AWAITING_LABEL: 'awaiting response'
  # Cap on PRs examined per run, most recently updated first.
  MAX_PRS: 200

jobs:
  scan:
    runs-on: ubuntu-latest
    steps:
      - name: Label open PRs that are awaiting an author response
        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 #v9.0.0
        with:
          script: |
            const awaitingLabel = process.env.AWAITING_LABEL;
            const maxPrs = parseInt(process.env.MAX_PRS, 10);
            const { owner, repo } = context.repo;

            // This scan only ADDS the label. Removal is handled by the
            // event-driven workflow (awaiting-response-label.yml) when the
            // author pushes or comments, or manually by a maintainer.
            const prs = await github.paginate(github.rest.pulls.list, {
              owner, repo, state: 'open', sort: 'updated', direction: 'desc', per_page: 100,
            });

            let examined = 0;
            for (const prSummary of prs) {
              if (examined >= maxPrs) {
                core.info(`Reached MAX_PRS (${maxPrs}); stopping.`);
                break;
              }
              examined++;

              if (prSummary.labels.some(l => l.name === awaitingLabel)) {
                continue;
              }

              // A reviewer requested changes and the author hasn't responded.
              // (Merge conflicts are intentionally not labelled here: maintainers
              // usually know the reason and clean these up as part of the merge
              // process, or leave a review comment asking the author to resolve
              // it, which is then caught by the check below.)
              const { data: pr } = await github.rest.pulls.get({
                owner, repo, pull_number: prSummary.number,
              });

              const reviews = await github.paginate(github.rest.pulls.listReviews, {
                owner, repo, pull_number: pr.number, per_page: 100,
              });
              // Note: the REST API reports review states in UPPERCASE
              // ("CHANGES_REQUESTED"), unlike webhook payloads which are lowercase.
              const decisive = reviews.filter(r =>
                r.state === 'CHANGES_REQUESTED' || r.state === 'APPROVED'
              );
              const latest = decisive[decisive.length - 1];
              if (!latest || latest.state !== 'CHANGES_REQUESTED') {
                continue;
              }

              // If the author has pushed since the review, treat that as a response
              // (same rule as the event-driven removal workflow).
              if (latest.commit_id !== pr.head.sha) {
                continue;
              }

              // If the author has commented since the review, that also counts
              // as a response.
              const comments = await github.paginate(github.rest.issues.listComments, {
                owner, repo, issue_number: pr.number, since: latest.submitted_at, per_page: 100,
              });
              const authorResponded = comments.some(c =>
                (c.user?.login || '') === pr.user.login
              );
              if (authorResponded) {
                continue;
              }

              await github.rest.issues.addLabels({
                owner, repo, issue_number: pr.number, labels: [awaitingLabel],
              });
              core.info(`#${pr.number}: added "${awaitingLabel}" (changes requested, no response).`);
            }

            core.info(`Scan complete; examined ${examined} PR(s).`);