release.yml

name: Release

on:
  push:
    branches: [main]

permissions:
  contents: write

jobs:
  release:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      # pyproject.toml is the single source of truth for the version:
      # c64lib.__version__ is read from the installed metadata (derived from
      # pyproject), the CHANGELOG heading is test-locked to it, and this
      # workflow tags/releases exactly that version. A commit that bumps
      # pyproject IS the release; any other push is a no-op.
      - name: Read version from pyproject.toml
        id: version
        run: |
          version=$(python3 -c "import tomllib; print(tomllib.load(open('pyproject.toml','rb'))['project']['version'])")
          echo "tag=v$version" >> "$GITHUB_OUTPUT"
          if git rev-parse -q --verify "refs/tags/v$version" >/dev/null; then
            echo "exists=true" >> "$GITHUB_OUTPUT"
          else
            echo "exists=false" >> "$GITHUB_OUTPUT"
          fi

      - uses: actions/setup-python@v5
        if: steps.version.outputs.exists == 'false'
        with:
          python-version: "3.12"

      - name: Build packages
        if: steps.version.outputs.exists == 'false'
        run: |
          python -m pip install --quiet build
          python -m build

      - name: Create release
        if: steps.version.outputs.exists == 'false'
        env:
          GH_TOKEN: ${{ github.token }}
        run: >
          gh release create "${{ steps.version.outputs.tag }}"
          --target "$GITHUB_SHA"
          --generate-notes
          dist/*