name: release

# Tag-driven. Cargo.toml carries the version; the tag only points at it, and the
# first step refuses to go on if the two disagree — a release tagged v0.3.0 that
# publishes 0.2.0 cannot be undone, because PyPI will not let a version be reused
# even after it is yanked.
on:
  push:
    tags: ['v*']

# One job on purpose. Splitting build from publish would mean passing wheels
# between jobs through actions/upload-artifact, which is a JavaScript action: the
# runner executes it with `node` inside this container, and a Rust image has none.
# Everything a release needs fits in one job, so nothing has to be handed over.
jobs:
  publish:
    runs-on: docker
    container:
      image: rust:1.98-bookworm
    steps:
      - name: Checkout
        run: |
          git init -q .
          git remote add origin "$GITHUB_SERVER_URL/$GITHUB_REPOSITORY"
          git fetch -q --depth 1 origin "$GITHUB_SHA"
          git checkout -q FETCH_HEAD

      - name: Tag must match Cargo.toml
        run: |
          tag="${GITHUB_REF_NAME#v}"
          crate=$(grep -m1 '^version = ' Cargo.toml | cut -d'"' -f2)
          echo "tag=$tag crate=$crate"
          [ "$tag" = "$crate" ] || { echo "::error::tag $tag != Cargo.toml $crate"; exit 1; }

      - name: Tests
        run: cargo test

      - name: Build wheels and sdist
        run: |
          apt-get update && apt-get install -y --no-install-recommends python3 python3-venv
          python3 -m venv /tmp/venv
          # readme-renderer[md] is what makes `twine check` actually parse the
          # long description. Without it the render returns None and the
          # check reports PASSED regardless, even with --strict.
          /tmp/venv/bin/pip install 'maturin[zig]' twine 'readme-renderer[md]'
          # The venv has to be first on PATH, not merely called by absolute
          # path. maturin looks for zig by running `python3 -m ziglang`, and
          # `maturin[zig]` puts ziglang in the venv only, so a bare python3
          # resolves to the system one, which does not have it: "Failed to find
          # zig", after apt and rustup have already run.
          export PATH="/tmp/venv/bin:$PATH"
          python3 -m ziglang version
          # --zig cross-compiles against an older glibc than this image ships, so
          # the wheel is not silently pinned to bookworm's.
          for target in x86_64-unknown-linux-gnu aarch64-unknown-linux-gnu; do
            rustup target add "$target"
            maturin build --release --zig --target "$target" --out dist
          done
          maturin sdist --out dist
          ls -l dist

      - name: Publish
        env:
          # A project-scoped token, not the account-wide one. PyPI's trusted
          # publishing is OIDC and supports GitHub, GitLab, Google Cloud Build and
          # ActiveState — not Forgejo — so this forge has to hold a long-lived
          # credential. Scoping it to this one project is the whole of the
          # mitigation available: if the forge is compromised, what is lost is the
          # ability to publish typikon rather than every package the account owns.
          TWINE_USERNAME: __token__
          TWINE_PASSWORD: ${{ secrets.PYPI_TOKEN }}
        run: |
          # By absolute path: each step gets its own shell, so the PATH the
          # build step exported for zig's sake does not reach this one.
          /tmp/venv/bin/twine check --strict dist/*
          # --skip-existing so a retry after a partial upload finishes the job
          # instead of dying on the first file. A version cannot be reused,
          # so a half-published release would otherwise burn it.
          /tmp/venv/bin/twine upload --non-interactive --skip-existing dist/*