release.yml

name: Release

on:
  pull_request:
    types: [closed]
    branches: [main]
  workflow_dispatch:
    inputs:
      bump:
        description: "Version bump type"
        required: true
        type: choice
        options:
          - patch
          - minor
          - major

env:
  CARGO_TERM_COLOR: always

jobs:
  prepare-release:
    if: github.event_name == 'workflow_dispatch'
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
    steps:
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0

      - name: Calculate new version
        id: version
        run: |
          CURRENT=$(grep '^version' Cargo.toml | head -1 | sed 's/version = "\(.*\)"/\1/')
          IFS='.' read -r MAJOR MINOR PATCH <<< "$CURRENT"

          case "${{ inputs.bump }}" in
            major) MAJOR=$((MAJOR + 1)); MINOR=0; PATCH=0 ;;
            minor) MINOR=$((MINOR + 1)); PATCH=0 ;;
            patch) PATCH=$((PATCH + 1)) ;;
          esac

          NEW="${MAJOR}.${MINOR}.${PATCH}"
          echo "current=$CURRENT" >> "$GITHUB_OUTPUT"
          echo "new=$NEW" >> "$GITHUB_OUTPUT"
          echo "Bumping $CURRENT -> $NEW"

      - uses: dtolnay/rust-toolchain@stable

      - name: Update Cargo.toml version
        run: |
          sed -i "s/^version = \"${{ steps.version.outputs.current }}\"/version = \"${{ steps.version.outputs.new }}\"/" Cargo.toml
          cargo update --workspace

      - name: Generate changelog entry
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          VERSION="${{ steps.version.outputs.new }}"
          DATE=$(date +%Y-%m-%d)
          PREVIOUS_TAG=$(git tag -l "v*" --sort=-v:refname | head -1)

          if [ -n "$PREVIOUS_TAG" ]; then
            NOTES=$(gh api repos/${{ github.repository }}/releases/generate-notes \
              -f tag_name="v${VERSION}" \
              -f target_commitish=main \
              -f previous_tag_name="$PREVIOUS_TAG" \
              --jq '.body')
          else
            NOTES="- Initial release"
          fi

          {
            echo "## [${VERSION}] - ${DATE}"
            echo ""
            echo "$NOTES"
            echo ""
          } > /tmp/changelog-entry.md

      - name: Update changelog
        run: |
          {
            head -n 4 CHANGELOG.md
            cat /tmp/changelog-entry.md
            echo ""
            tail -n +5 CHANGELOG.md
          } > CHANGELOG.tmp && mv CHANGELOG.tmp CHANGELOG.md

      - name: Create release PR
        uses: peter-evans/create-pull-request@v8
        with:
          branch: release/v${{ steps.version.outputs.new }}
          commit-message: "release: v${{ steps.version.outputs.new }}"
          title: "release: v${{ steps.version.outputs.new }}"
          body: "Bumps version from ${{ steps.version.outputs.current }} to ${{ steps.version.outputs.new }}."
          labels: release

  publish:
    if: >-
      github.event.pull_request.merged == true &&
      startsWith(github.event.pull_request.head.ref, 'release/')
    runs-on: ubuntu-latest
    permissions:
      contents: write
    steps:
      - uses: actions/checkout@v6

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

      - name: Get version and publish
        env:
          GH_TOKEN: ${{ github.token }}
          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}
        run: |
          VERSION=$(grep '^version' Cargo.toml | head -1 | sed 's/version = "\(.*\)"/\1/')
          TAG="v${VERSION}"

          # Extract changelog entry for this version
          NOTES=$(sed -n "/^## \[${VERSION}\]/,/^## \[/{ /^## \[${VERSION}\]/p; /^## \[${VERSION}\]/!{ /^## \[/!p; } }" CHANGELOG.md)

          # Tag and push
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git tag "$TAG"
          git push origin "$TAG"

          # Update major version tag (e.g., v1) for action consumers
          MAJOR_TAG="v$(echo "$VERSION" | cut -d. -f1)"
          git tag -f "$MAJOR_TAG"
          git push origin "$MAJOR_TAG" -f

          # Publish to crates.io
          cargo publish

          # Create GitHub release with changelog as notes
          echo "$NOTES" > /tmp/release-notes.md
          gh release create "$TAG" \
            --title "v${VERSION}" \
            --notes-file /tmp/release-notes.md