gitprint 0.4.0

name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  # ── Lint (fast) ──────────────────────────────────────────────────────────────
  # Surfaces formatting and clippy failures in ~1 min, independently of tests.
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      - run: cargo fmt -- --check
      - run: cargo clippy --all-targets -- -D warnings

  # ── Test ─────────────────────────────────────────────────────────────────────
  # Runs in parallel with lint; nextest executes tests in parallel processes
  # (~2× faster than cargo test on multi-core runners).
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      - uses: taiki-e/install-action@v2
        with:
          tool: nextest
      - run: cargo nextest run

  # ── Binary ───────────────────────────────────────────────────────────────────
  # Compiles a musl release binary in parallel with lint/test. Uses thin LTO
  # (acceptable for nightly; fat LTO is reserved for shipped release binaries).
  # The package and pages jobs download this artifact instead of recompiling.
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - name: Install musl toolchain
        run: sudo apt-get install -y musl-tools
      - run: rustup target add x86_64-unknown-linux-musl
      - uses: Swatinem/rust-cache@v2
        with:
          key: musl
      - name: Build
        env:
          CARGO_PROFILE_RELEASE_LTO: thin
          CARGO_PROFILE_RELEASE_CODEGEN_UNITS: "16"
        run: cargo build --release --target x86_64-unknown-linux-musl
      - run: tar czf gitprint-linux-musl.tar.gz -C target/x86_64-unknown-linux-musl/release gitprint
      - uses: actions/upload-artifact@v4
        with:
          name: gitprint-linux-musl
          path: gitprint-linux-musl.tar.gz
          retention-days: 1

  # ── Docker image ─────────────────────────────────────────────────────────────
  # Downloads the pre-built musl binary from the build job and copies it into
  # Alpine via --target prebuilt — no Rust compilation inside Docker.
  #
  # Push policy:
  #   - main branch  → ghcr.io/.../gitprint:nightly + sha-<hash>
  #   - other branches / same-repo PRs → ghcr.io/.../gitprint:<branch> or pr-<n>
  #   - fork PRs → build only, no push (fork tokens lack GHCR write access)
  package:
    needs: [lint, test, build]
    runs-on: ubuntu-latest
    permissions:
      packages: write
    steps:
      - uses: actions/checkout@v4

      - uses: docker/setup-buildx-action@v3

      # Login is skipped for fork PRs — their GITHUB_TOKEN cannot write to the
      # upstream registry. Same-repo PRs and all push events have write access.
      - uses: docker/login-action@v3
        if: >-
          github.event_name == 'push' ||
          github.event.pull_request.head.repo.full_name == github.repository
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Tags:
      #   push to main  → nightly + sha-<hash>
      #   push to branch → <branch-name> + sha-<hash>
      #   same-repo PR   → pr-<number> + sha-<hash>
      - uses: docker/metadata-action@v5
        id: meta
        with:
          images: ghcr.io/${{ github.repository }}
          tags: |
            type=raw,value=nightly,enable=${{ github.ref == 'refs/heads/main' }}
            type=ref,event=branch
            type=ref,event=pr
            type=sha,prefix=sha-,format=short

      - uses: actions/download-artifact@v4
        with:
          name: gitprint-linux-musl
          path: dist
      - run: tar xzf dist/gitprint-linux-musl.tar.gz -C dist

      - uses: docker/build-push-action@v6
        with:
          context: dist
          file: Dockerfile
          target: prebuilt
          push: >-
            ${{
              github.event_name == 'push' ||
              github.event.pull_request.head.repo.full_name == github.repository
            }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}

  # ── Pages (main only) ────────────────────────────────────────────────────────
  # Reuses the pre-built musl binary to generate the source PDF (skips
  # cargo build --release), then builds rustdoc and deploys both to GitHub Pages.
  # Runs only on main; concurrency guard cancels stale in-flight deployments.
  pages:
    if: github.ref == 'refs/heads/main'
    needs: [lint, test, build]
    runs-on: ubuntu-latest
    concurrency:
      group: pages
      cancel-in-progress: true
    permissions:
      contents: read
      pages: write
      id-token: write
    environment:
      name: github-pages
      url: ${{ steps.deploy.outputs.page_url }}
    steps:
      - uses: actions/checkout@v4
        with:
          # Full history required so git log reports accurate per-file dates.
          fetch-depth: 0

      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2

      # Reuse the already-compiled musl binary — no cargo build --release needed.
      - uses: actions/download-artifact@v4
        with:
          name: gitprint-linux-musl
          path: dist
      - run: tar xzf dist/gitprint-linux-musl.tar.gz -C dist && chmod +x dist/gitprint

      - name: Generate PDF
        run: ./dist/gitprint . --output gitprint.pdf

      - name: Generate rustdoc
        run: cargo doc --no-deps

      - name: Assemble site
        env:
          REPO: ${{ github.repository }}
        run: |
          mkdir -p _site/docs
          cp gitprint.pdf _site/gitprint.pdf
          cp -r target/doc/. _site/docs/
          touch _site/.nojekyll
          cat > _site/index.html << HTMLEOF
          <!DOCTYPE html>
          <html lang="en">
          <head>
            <meta charset="UTF-8">
            <meta name="viewport" content="width=device-width, initial-scale=1.0">
            <title>gitprint — source PDF</title>
            <style>
              * { margin: 0; padding: 0; box-sizing: border-box; }
              html, body { height: 100%; font-family: system-ui, -apple-system, sans-serif; background: #0d1117; color: #e6edf3; }
              body { display: flex; flex-direction: column; }
              header { flex-shrink: 0; display: flex; align-items: center; gap: 16px; padding: 10px 20px; background: #161b22; border-bottom: 1px solid #30363d; }
              header h1 { font-size: 15px; font-weight: 600; letter-spacing: -.01em; }
              header a { font-size: 13px; color: #8b949e; text-decoration: none; }
              header a:hover { color: #e6edf3; }
              embed { flex: 1; width: 100%; border: none; }
            </style>
          </head>
          <body>
            <header>
              <h1>gitprint</h1>
              <a href="https://github.com/${REPO}">source</a>
              <a href="gitprint.pdf">download PDF</a>
              <a href="docs/gitprint/index.html">API docs</a>
            </header>
            <embed src="gitprint.pdf" type="application/pdf">
          </body>
          </html>
          HTMLEOF

      - uses: actions/configure-pages@v4
      - uses: actions/upload-pages-artifact@v3
        with:
          path: _site
      - id: deploy
        uses: actions/deploy-pages@v4

  # ── Benchmarks (main only) ────────────────────────────────────────────────────
  # Run all benchmarks and record results as "current". No regression
  # comparison here — GitHub-hosted runners have too much performance
  # variance between runs to produce a reliable baseline. The authoritative
  # check runs locally via `make bench-check` / `make release`, where
  # hardware is consistent. Skipped on PRs since results would be discarded.
  benchmark:
    if: github.ref == 'refs/heads/main'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      - name: Run benchmarks
        run: cargo bench --bench pipeline -- --save-baseline current