lighthouse.yml

name: lighthouse

on:
  pull_request:
    branches: ['**']

permissions:
  pull-requests: write
  contents: write
  deployments: read
  statuses: read
  actions: read

jobs:
  lighthouse:
    # Skip admin-dashboard PRs. Those auto-merge once validate-content
    # passes and don't need perf gating on every text tweak; if they
    # introduce a regression the next hand-authored PR will catch it.
    if: ${{ !startsWith(github.head_ref, 'admin/') }}
    name: Lighthouse audit against CF Pages preview
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Wait for Cloudflare Pages preview
        id: cf-preview
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          # Poll the PR's deployments for the CF Pages "preview" environment.
          # Fall back to a 90s sleep if no deployment shows up.
          owner_repo="${{ github.repository }}"
          sha="${{ github.event.pull_request.head.sha }}"
          url=""
          for i in $(seq 1 30); do
            url=$(gh api "repos/$owner_repo/deployments?sha=$sha" --jq \
              '[.[] | select(.environment | test("preview|Preview"))][0].payload.web_url // empty' 2>/dev/null || true)
            if [ -n "$url" ]; then
              echo "Preview ready: $url"
              break
            fi
            statuses_url=$(gh api "repos/$owner_repo/commits/$sha/status" --jq \
              '[.statuses[] | select(.context | test("Cloudflare Pages|cloudflare/pages"))][0].target_url // empty' 2>/dev/null || true)
            if [ -n "$statuses_url" ]; then
              url="$statuses_url"
              echo "Preview ready (via status): $url"
              break
            fi
            echo "Waiting for preview deploy ($i/30)..."
            sleep 15
          done

          if [ -z "$url" ]; then
            echo "::warning::No CF Pages preview detected after 7.5min; falling back to staging URL"
            url="https://website.ontargetnotes.com/"
          fi
          echo "preview_url=$url" >> "$GITHUB_OUTPUT"

      - name: Run Lighthouse CI
        id: lhci
        uses: treosh/lighthouse-ci-action@v12
        with:
          urls: ${{ steps.cf-preview.outputs.preview_url }}
          uploadArtifacts: true
          temporaryPublicStorage: true

      - name: Score gate + baseline comparison
        id: gate
        run: |
          python3 - <<'PY'
          import json, os, pathlib, sys, glob

          # Collect the LHCI manifest produced by treosh's action.
          manifests = glob.glob(".lighthouseci/manifest.json")
          if not manifests:
              print("::warning::No LHCI manifest found; skipping gate.")
              sys.exit(0)

          rep = json.loads(pathlib.Path(manifests[0]).read_text())
          # Use the median run if present.
          run = next((r for r in rep if r.get("isRepresentativeRun")), rep[0])
          summary = run.get("summary", {})

          scores = {
              "performance":    round(summary.get("performance", 0) * 100, 1),
              "accessibility":  round(summary.get("accessibility", 0) * 100, 1),
              "seo":            round(summary.get("seo", 0) * 100, 1),
              "best-practices": round(summary.get("best-practices", 0) * 100, 1),
          }
          print("Scores:", scores)

          thresholds = {"performance": 90, "accessibility": 95, "seo": 95, "best-practices": 90}
          failures = [k for k, v in scores.items() if v < thresholds[k]]

          baseline_path = pathlib.Path(".github/lighthouse-baseline.json")
          regression = []
          if baseline_path.exists():
              try:
                  baseline = json.loads(baseline_path.read_text())
                  for k, v in scores.items():
                      if k in baseline and v < baseline[k] - 5:
                          regression.append(f"{k}: {v} (baseline {baseline[k]}, drop > 5)")
              except Exception as e:
                  print(f"::warning::Could not parse baseline: {e}")
          else:
              print("No baseline found; recording current scores as baseline.")
              baseline_path.parent.mkdir(parents=True, exist_ok=True)
              baseline_path.write_text(json.dumps(scores, indent=2))

          with open(os.environ["GITHUB_OUTPUT"], "a") as f:
              for k, v in scores.items():
                  f.write(f"{k}={v}\n")
              f.write(f"failures={','.join(failures)}\n")
              f.write(f"regression={'; '.join(regression)}\n")

          if failures or regression:
              print(f"::error::Failed thresholds: {failures}; regressions: {regression}")
              sys.exit(1)
          PY

      - name: Commit baseline if new
        if: always()
        run: |
          if [ -f .github/lighthouse-baseline.json ] && \
             ! git diff --quiet -- .github/lighthouse-baseline.json; then
            git config user.name "github-actions[bot]"
            git config user.email "github-actions[bot]@users.noreply.github.com"
            git add .github/lighthouse-baseline.json
            git commit -m "chore: record Lighthouse baseline [skip ci]" || true
            git push || true
          fi

      - name: Comment on PR
        if: always()
        uses: actions/github-script@v7
        with:
          script: |
            const out = ${{ toJson(steps.gate.outputs) }};
            const body = [
              '### Lighthouse',
              '',
              `- performance: **${out.performance}**`,
              `- accessibility: **${out.accessibility}**`,
              `- seo: **${out.seo}**`,
              `- best-practices: **${out['best-practices']}**`,
              out.failures ? `\n:x: Failures: ${out.failures}` : '',
              out.regression ? `\n:warning: Regressions: ${out.regression}` : '',
            ].join('\n');
            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body,
            });