auto-label.yml

name: Auto-label PRs

on:
  pull_request:
    types: [opened, synchronize]
  workflow_dispatch:
    inputs:
      pr_number:
        description: 'PR number to label'
        required: true
        type: number

permissions: {}

concurrency:
  group: auto-label-${{ github.event.number || inputs.pr_number }}
  cancel-in-progress: true

jobs:
  # -----------------------------------------------------------------
  # Check if this re-run would create skipped check runs that
  # overwrite existing successful status.
  # -----------------------------------------------------------------
  check-existing-success:
    runs-on: ubuntu-latest
    permissions:
      checks: read
      pull-requests: read
    outputs:
      should-run: ${{ steps.check.outputs.should-run }}
    steps:
      - name: Check if re-run would overwrite successful status
        id: check
        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd  # v8.0.0
        with:
          script: |
            const headSha = context.sha;
            const runId = context.runId;
            const runAttempt = Number(process.env.GITHUB_RUN_ATTEMPT) || 1;

            core.info(`Run info: SHA=${headSha}, runId=${runId}, attempt=${runAttempt}`);

            // First attempts always proceed
            if (runAttempt === 1) {
              core.info('First attempt - proceeding');
              core.setOutput('should-run', 'true');
              return;
            }

            // Check if jobs would actually run or would skip
            const pr = context.payload.pull_request;
            const isDraft = pr?.draft === true;
            const isFork = pr?.head?.repo?.full_name !== pr?.base?.repo?.full_name;
            const isWorkflowDispatch = context.eventName === 'workflow_dispatch';

            const jobsWouldRun = isWorkflowDispatch || (!isDraft && !isFork);

            if (jobsWouldRun) {
              core.info('Re-run would execute jobs - proceeding');
              core.setOutput('should-run', 'true');
              return;
            }

            // Jobs would be skipped. Check if successful runs already exist.
            core.info('Re-run would skip jobs - checking for existing successful runs');

            try {
              const { data: checkRuns } = await github.rest.checks.listForRef({
                owner: context.repo.owner,
                repo: context.repo.repo,
                ref: headSha,
                per_page: 100,
              });

              const successfulOtherRuns = checkRuns.check_runs.filter(cr => {
                const isOurJob = cr.name === 'auto-label' || cr.name === 'check-existing-success';
                const isSuccessful = cr.conclusion === 'success';
                const fromDifferentRun = cr.html_url && !cr.html_url.includes(`/runs/${runId}/`);
                return isOurJob && isSuccessful && fromDifferentRun;
              });

              if (successfulOtherRuns.length > 0) {
                core.info(`Found ${successfulOtherRuns.length} successful runs - aborting to preserve status`);
                core.setOutput('should-run', 'false');
                return;
              }
            } catch (error) {
              core.warning(`Could not check existing runs: ${error.message}`);
            }

            core.info('No existing successful runs - proceeding');
            core.setOutput('should-run', 'true');

  auto-label:
    needs: check-existing-success
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
    # Skip draft PRs and fork PRs (workflow_dispatch always runs)
    if: |
      needs.check-existing-success.outputs.should-run == 'true' &&
      (github.event_name == 'workflow_dispatch' ||
       (!github.event.pull_request.draft &&
        github.event.pull_request.head.repo.full_name == github.repository))
    steps:
      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
        with:
          persist-credentials: false
          sparse-checkout: |
            content
            data/products.yml
            scripts/lib/content-utils.js
            .github/scripts/workflow-utils.js
            package.json
          sparse-checkout-cone-mode: false

      - uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f  # v6.3.0
        with:
          node-version: 22

      - name: Install js-yaml
        run: npm install --no-save --ignore-scripts --no-package-lock --legacy-peer-deps js-yaml

      - name: Apply product labels
        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd  # v8.0.0
        with:
          script: |
            const {
              getProductLabelMap,
              matchFilesToLabels,
            } = await import(
              `${process.cwd()}/.github/scripts/workflow-utils.js`
            );

            const prNumber =
              context.issue.number ||
              Number('${{ inputs.pr_number }}');

            if (!prNumber) {
              core.setFailed('No PR number available');
              return;
            }

            // --- Build path-to-label mapping from products.yml ---
            const pathToLabel = await getProductLabelMap();
            core.info(
              `Loaded ${pathToLabel.size} path-to-label mappings from products.yml`
            );

            // --- Get changed files from the PR (paginated) ---
            const files = await github.paginate(
              github.rest.pulls.listFiles,
              {
                owner: context.repo.owner,
                repo: context.repo.repo,
                pull_number: prNumber,
                per_page: 100,
              }
            );

            const changedFiles = files.map(f => f.filename);
            core.info(`PR has ${changedFiles.length} changed files`);

            // --- Match files to product labels ---
            const labelsToAdd = matchFilesToLabels(changedFiles, pathToLabel);

            if (labelsToAdd.size === 0) {
              core.info('No product labels to add');
              return;
            }

            // --- Get existing PR labels to avoid duplicates ---
            const { data: prData } = await github.rest.issues.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: prNumber,
            });

            const existingLabels = new Set(prData.labels.map(l => l.name));
            const newLabels = [...labelsToAdd].filter(
              l => !existingLabels.has(l)
            );

            if (newLabels.length === 0) {
              core.info('All matching labels already present');
              return;
            }

            // --- Apply labels ---
            await github.rest.issues.addLabels({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: prNumber,
              labels: newLabels,
            });

            core.info(`Added labels: ${newLabels.join(', ')}`);