name: PR Comment

on:
  workflow_run:
    workflows: ["PR Check"]
    types: [completed]
  pull_request_review:
    types: [submitted]

permissions:
  actions: read
  checks: read
  contents: read
  pull-requests: write

jobs:
  comment:
    name: Post PR comment
    runs-on: ubuntu-latest
    if: github.event.workflow_run.event == 'pull_request'

    steps:
      - uses: actions/checkout@v4

      - name: Download PR metadata
        id: download
        continue-on-error: true
        uses: actions/download-artifact@v4
        with:
          name: pr-meta
          path: pr-meta
          run-id: ${{ github.event.workflow_run.id }}
          github-token: ${{ secrets.GITHUB_TOKEN }}

      - name: Resolve PR context
        id: context
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.BOT_TOKEN || secrets.GITHUB_TOKEN }}
          script: |
            const fs = require('fs');

            // Determine the PR number
            let prNumber;
            const numberFile = 'pr-meta/number.txt';
            if (fs.existsSync(numberFile)) {
              prNumber = parseInt(fs.readFileSync(numberFile, 'utf8').trim());
            }
            if (!prNumber) {
              const prs = context.payload.workflow_run.pull_requests;
              if (prs && prs.length > 0) {
                prNumber = prs[0].number;
              } else {
                const headSha = context.payload.workflow_run.head_sha;
                const { data: prList } = await github.rest.pulls.list({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  state: 'open',
                  sort: 'updated',
                  direction: 'desc',
                  per_page: 100,
                });
                const match = prList.find(pr => pr.head.sha === headSha);
                if (!match) {
                  console.log(`No open PR found for SHA ${headSha} — skipping.`);
                  return;
                }
                prNumber = match.number;
              }
            }

            // Fetch existing bot comment (if any) and write to file for Python
            const marker = '<!-- pr-check-bot -->';
            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: prNumber,
              per_page: 100,
            });
            const existing = comments.find(c => c.body.includes(marker));
            if (existing) {
              fs.mkdirSync('pr-meta', { recursive: true });
              fs.writeFileSync('pr-meta/existing-comment.md', existing.body);
              fs.writeFileSync('pr-meta/existing-comment-id.txt', String(existing.id));
            }

            core.setOutput('pr_number', prNumber);

      - name: Prepare comment
        if: steps.context.outputs.pr_number
        env:
          CHECK_RUN_ID: ${{ github.event.workflow_run.id }}
          GITHUB_REPOSITORY: ${{ github.repository }}
        run: python lib/checks/prepare-comment.py

      - name: Post or update comment
        if: steps.context.outputs.pr_number
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.BOT_TOKEN || secrets.GITHUB_TOKEN }}
          script: |
            const fs = require('fs');
            const actionFile = 'pr-meta/action.txt';
            if (!fs.existsSync(actionFile)) return;

            const action = fs.readFileSync(actionFile, 'utf8').trim();
            if (action === 'skip') {
              console.log('Nothing to do — skipping.');
              return;
            }

            const bodyFile = 'pr-meta/final-comment.md';
            if (!fs.existsSync(bodyFile)) {
              console.log('No comment body found — skipping.');
              return;
            }
            const body = fs.readFileSync(bodyFile, 'utf8').trim();
            const prNumber = parseInt('${{ steps.context.outputs.pr_number }}');

            if (action === 'create') {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: prNumber,
                body,
              });
              console.log('Created bot comment.');
            } else if (action === 'update') {
              const commentId = parseInt(fs.readFileSync('pr-meta/existing-comment-id.txt', 'utf8').trim());
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: commentId,
                body,
              });
              console.log('Updated bot comment.');
            }

  review-notify:
    name: Notify maintainer
    runs-on: ubuntu-latest
    if: github.event_name == 'pull_request_review'

    steps:
      - uses: actions/checkout@v4

      - name: Fetch review and CI context
        id: context
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.BOT_TOKEN || secrets.GITHUB_TOKEN }}
          script: |
            const fs = require('fs');
            const pr = context.payload.pull_request;
            const { owner, repo } = context.repo;

            // Fetch reviews — extract user login and state
            const { data: reviews } = await github.rest.pulls.listReviews({
              owner, repo, pull_number: pr.number, per_page: 100,
            });
            const reviewData = reviews.map(r => ({
              user: r.user.login,
              state: r.state,
            }));

            // Fetch check runs for the PR head SHA
            const { data: { check_runs } } = await github.rest.checks.listForRef({
              owner, repo, ref: pr.head.sha, per_page: 100,
            });
            const checkData = check_runs.map(cr => ({
              status: cr.status,
              conclusion: cr.conclusion,
            }));

            // Check if we already posted the notification
            const marker = '<!-- pr-review-ready -->';
            const { data: comments } = await github.rest.issues.listComments({
              owner, repo, issue_number: pr.number, per_page: 100,
            });
            const alreadyNotified = comments.some(c => c.body.includes(marker));

            // Write data for Python
            fs.mkdirSync('pr-meta', { recursive: true });
            fs.writeFileSync('pr-meta/reviews.json', JSON.stringify(reviewData));
            fs.writeFileSync('pr-meta/check-runs.json', JSON.stringify(checkData));
            fs.writeFileSync('pr-meta/already-notified.txt', String(alreadyNotified));

            core.setOutput('pr_number', pr.number);

      - name: Check review readiness
        run: python lib/checks/check-review-ready.py

      - name: Post notification
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.BOT_TOKEN || secrets.GITHUB_TOKEN }}
          script: |
            const fs = require('fs');
            const actionFile = 'pr-meta/action.txt';
            if (!fs.existsSync(actionFile)) return;

            const action = fs.readFileSync(actionFile, 'utf8').trim();
            if (action !== 'notify') {
              console.log('Not ready for review — skipping.');
              return;
            }

            const body = [
              '<!-- pr-review-ready -->',
              'This PR is now ready to be merged, pending maintainer review. All checks are passing and it has been peer-reviewed.',
              '',
              '@Lissy93 - Please evaluate, and either merge or leave feedback.',
            ].join('\n');

            await github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: parseInt('${{ steps.context.outputs.pr_number }}'),
              body,
            });
            console.log('Posted maintainer notification.');