name: Draft GitHub Release

# Runs when a new tag is created that looks like a version number.
#
# Creates a draft release on GitHub with the latest release notes, then chains
# to the build_and_test workflow and the publish_github_release workflow.
#
# Collectively, this will build and tests on all OSes, attach release artifacts
# to the release, and fully publish the release.
#
# Publishing the release then triggers additional workflows for NPM, Docker
# Hub, and GitHub Pages.
#
# Can also be run manually for debugging purposes.
on:
  push:
    tags:
      - "v*.*"
  # For manual debugging:
  workflow_dispatch:
    inputs:
      tag:
        description: "An existing tag to release."
        required: True

jobs:
  draft_release:
    name: Draft GitHub release
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v2
        with:
          path: src

      - name: Compute ref
        # We could be building from a workflow dispatch (manual run)
        # or from a pushed tag.  If triggered from a pushed tag, we would like
        # to strip refs/tags/ off of the incoming ref and just use the tag
        # name.  Subsequent steps can refer to $TARGET_REF to determine the
        # correct ref in all cases.
        run: |
          echo "TARGET_REF=${{ github.event.inputs.tag || github.ref }}" | \
              sed -e 's@refs/tags/@@' >> $GITHUB_ENV

      - name: Extract release notes
        run: |
          cd src
          packager/tools/extract_from_changelog.py --release_notes \
              | tee ../RELEASE_NOTES.md
          # This check prevents releases without appropriate changelog updates.
          VERSION=$(packager/tools/extract_from_changelog.py --version)
          if [[ "$VERSION" != "$TARGET_REF" ]]; then
            echo ""
            echo ""
            echo "***** ***** *****"
            echo ""
            echo "Version mismatch!"
            echo "Workflow is targetting $TARGET_REF,"
            echo "but CHANGELOG.md contains $VERSION!"
            exit 1
          fi

      - name: Draft release
        id: draft_release
        uses: actions/create-release@v1
        env:
          GITHUB_TOKEN: ${{ secrets.SHAKA_BOT_TOKEN }}
        with:
          tag_name: ${{ env.TARGET_REF }}
          release_name: ${{ env.TARGET_REF }}
          body_path: RELEASE_NOTES.md
          draft: true

      - name: Start build and test, then publish
        run: |
          cd src
          gh workflow run build_and_test.yaml \
              -f 'ref=${{ env.TARGET_REF }}' \
              -f 'release_id=${{ steps.draft_release.outputs.id }}' \
              -f 'next_workflow=publish_github_release.yaml' \
              -f 'next_workflow_payload={ "release_id": "${{ steps.draft_release.outputs.id }}" }'
          echo "Triggered build_and_test workflow for release ID ${{ steps.draft_release.outputs.id }}."
        env:
          GITHUB_TOKEN: ${{ secrets.SHAKA_BOT_TOKEN }}