on:
  workflow_run:
    workflows: [pyperformance]
    types: [completed]

name: pyperformance comment

# Same split as `codspeed-comment.yaml`: a `pull_request` run from a fork gets
# a read-only token however it is configured, so the comparison is computed
# there and handed over as an artifact, and this workflow -- which
# `workflow_run` always runs in the base repo's context -- is the one trusted
# with a token that may write the comment.
permissions:
  contents: read
  actions: read # needed by download-artifact to fetch another run's artifact
  pull-requests: write

jobs:
  comment:
    if: ${{ github.event.workflow_run.conclusion == 'success' }}
    runs-on: ubuntu-latest
    steps:
      - name: Download the comparison produced by the pyperformance workflow
        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
        with:
          name: pyperformance-diff
          run-id: ${{ github.event.workflow_run.id }}
          github-token: ${{ github.token }}
        continue-on-error: true # absent when the job was skipped or dispatched

      - name: Post or update the PR comment
        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
        with:
          script: |
            const fs = require('fs');
            if (!fs.existsSync('diff.md')) {
              core.info('No diff.md in this run; nothing to comment.');
              return;
            }

            const marker = '<!-- pyperformance-local-diff -->';
            const run = context.payload.workflow_run;
            let prNumber = (run.pull_requests || []).map((pr) => pr.number)[0];
            if (!prNumber) {
              const { data } = await github.rest.repos.listPullRequestsAssociatedWithCommit({
                owner: context.repo.owner,
                repo: context.repo.repo,
                commit_sha: run.head_sha,
              });
              prNumber = data.find((pr) => pr.state === 'open')?.number;
            }
            if (!prNumber) {
              core.info(`No open pull request for ${run.head_sha}; nothing to comment.`);
              return;
            }

            const raw = fs.readFileSync('diff.md', 'utf8').slice(0, 60000);
            const body = `${marker}\n\n${raw.replace(/<!--/g, '<!-​-')}`;

            const comments = await github.paginate(github.rest.issues.listComments, {
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: prNumber,
            });
            const existing = comments.find((c) => c.body && c.body.includes(marker));

            if (existing) {
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existing.id,
                body,
              });
            } else {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: prNumber,
                body,
              });
            }