name: comment

on:
  workflow_run:
    workflows: ["build"]
    types: [completed]

jobs:
  pr_comment:
    if: github.event.workflow_run.event == 'pull_request' && github.event.workflow_run.conclusion == 'success'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/github-script@v6
        with:
          script: |
            const { owner, repo } = context.repo;
            const run_id = ${{ github.event.workflow_run.id }};
            const pull_head_sha = '${{github.event.workflow_run.head_sha}}';

            const issue_number = await(async () => {
              const pulls = await github.rest.pulls.list({ owner, repo });
              for await (const { data } of github.paginate.iterator(pulls)) {
                for (const pull of data) {
                  if (pull.head.sha === pull_head_sha) {
                    return pull.number;
                  }
                }
              }
            })();
            if (issue_number) {
              core.info(`Using pull request ${issue_number}`);
            } else {
              return core.error(`No matching pull request found`);
            }

            const { data: { artifacts } } = await github.rest.actions.listWorkflowRunArtifacts({ owner, repo, run_id });
            if (!artifacts.length) {
              return core.error(`No artifacts found`);
            }

            let body = `Download the artifacts for this pull request:\n\n<details><summary>Windows</summary>\n`;
            for (const art of artifacts) {
              const art_link = `https://nightly.link/${owner}/${repo}/actions/artifacts/${art.id}.zip`;
              if (art.name.includes('w64')) {
                body += `\n* [${art.name}](${art_link})`;
              }
            }
            body += `\n</details>`;

            const { data: comments } = await github.rest.issues.listComments({ repo, owner, issue_number });
            const existing_comment = comments.find((c) => c.user.login === 'github-actions[bot]');
            if (existing_comment) {
              core.info(`Updating comment ${existing_comment.id}`);
              await github.rest.issues.updateComment({ repo, owner, comment_id: existing_comment.id, body });
            } else {
              core.info(`Creating a comment`);
              await github.rest.issues.createComment({ repo, owner, issue_number, body });
            }