release.yml

name: Create GitHub Release

# Creates a GitHub Release when a version tag is pushed.
#
# If a release notes file exists at docs/release-notes/vX.Y.Z.md,
# it is used as the release body (published immediately).
# If no notes file exists, a draft release is created instead —
# someone must write the notes and publish manually.

on:
  push:
    tags: ['v*']

permissions:
  contents: write

jobs:
  create-release:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Extract version from tag
        run: |
          TAG_NAME=${GITHUB_REF#refs/tags/}
          echo "TAG_NAME=${TAG_NAME}" >> $GITHUB_ENV

          # Detect pre-releases (alpha, beta, rc)
          if [[ "$TAG_NAME" =~ (a|b|rc)[0-9]+ ]]; then
            echo "IS_PRERELEASE=true" >> $GITHUB_ENV
          else
            echo "IS_PRERELEASE=false" >> $GITHUB_ENV
          fi

      - name: Check for release notes file
        id: notes
        run: |
          NOTES_FILE="docs/release-notes/${TAG_NAME}.md"
          if [ -f "$NOTES_FILE" ]; then
            echo "found=true" >> $GITHUB_OUTPUT
            echo "path=${NOTES_FILE}" >> $GITHUB_OUTPUT
          else
            echo "found=false" >> $GITHUB_OUTPUT
          fi

      - name: Create release (with notes)
        if: steps.notes.outputs.found == 'true'
        run: |
          gh release create "$TAG_NAME" \
            --title "Underworld3 ${TAG_NAME}" \
            --notes-file "${{ steps.notes.outputs.path }}" \
            ${{ env.IS_PRERELEASE == 'true' && '--prerelease' || '' }}
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Create draft release (no notes file)
        if: steps.notes.outputs.found == 'false'
        run: |
          gh release create "$TAG_NAME" \
            --title "Underworld3 ${TAG_NAME}" \
            --draft \
            --generate-notes \
            --notes "$(printf '> **Release notes not yet written.**\n>\n> No file found at `docs/release-notes/%s.md`.\n> Please add release notes and publish this draft.\n\n---\n\n## Auto-generated commit log\n\n' "$TAG_NAME")$(gh api repos/${{ github.repository }}/releases/generate-notes -f tag_name="$TAG_NAME" --jq '.body' 2>/dev/null || echo 'See commit history for changes.')" \
            ${{ env.IS_PRERELEASE == 'true' && '--prerelease' || '' }}
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}