name: Release Changelog

on:
  release:
    types: [released]

permissions:
  contents: write
  pull-requests: write

jobs:
  update-changelog:
    runs-on: ubuntu-latest
    steps:
    - name: Checkout code
      uses: actions/checkout@v4

    - name: Run Go Changelog Generator
      run: |
        # Run the Go changelog generator, passing the release tag if available
        if [ "${{ github.event.release.tag_name }}" = "latest" ]; then
          go run tools/changelog/changelog.go > "${{ github.event.release.tag_name }}-changelog.md"
        else
          go run tools/changelog/changelog.go "${{ github.event.release.tag_name }}" > "${{ github.event.release.tag_name }}-changelog.md"
        fi

    - name: Handle changelog files
      run: |
        # Ensure that the CHANGELOG directory exists
        mkdir -p CHANGELOG

        # Extract Major.Minor version by removing the 'v' prefix from the tag name
        TAG_NAME=${{ github.event.release.tag_name }}
        CHANGELOG_VERSION_NUMBER=$(echo "$TAG_NAME" | sed 's/^v//' | grep -oP '^\d+\.\d+')

        # Define the new changelog file path
        CHANGELOG_FILENAME="CHANGELOG-$CHANGELOG_VERSION_NUMBER.md"
        CHANGELOG_PATH="CHANGELOG/$CHANGELOG_FILENAME"

        # Check if the changelog file for the current release already exists
        if [ -f "$CHANGELOG_PATH" ]; then
          # If the file exists, append the new changelog to the existing one
          cat "$CHANGELOG_PATH" >> "${TAG_NAME}-changelog.md"
          # Overwrite the existing changelog with the updated content
          mv "${TAG_NAME}-changelog.md" "$CHANGELOG_PATH"
        else
          # If the changelog file doesn't exist, rename the temp changelog file to the new changelog file
          mv "${TAG_NAME}-changelog.md" "$CHANGELOG_PATH"

          # Ensure that README.md exists
          if [ ! -f "CHANGELOG/README.md" ]; then
            echo -e "# CHANGELOGs\n\n" > CHANGELOG/README.md
          fi
          
            # Add the new changelog entry at the top of the README.md
            if ! grep -q "\[$CHANGELOG_FILENAME\]" CHANGELOG/README.md; then
            sed -i "3i- [$CHANGELOG_FILENAME](./$CHANGELOG_FILENAME)" CHANGELOG/README.md
            # Remove the extra newline character added by sed
            # sed -i '4d' CHANGELOG/README.md
            fi
          fi

    - name: Clean up
      run: |
        # Remove any temporary files that were created during the process
        rm -f "${{ github.event.release.tag_name }}-changelog.md"

    - name: Create Pull Request
      uses: peter-evans/create-pull-request@v7.0.5
      with:
        token: ${{ secrets.GITHUB_TOKEN }}
        commit-message: "Update CHANGELOG for release ${{ github.event.release.tag_name }}"
        title: "Update CHANGELOG for release ${{ github.event.release.tag_name }}"
        body: "This PR updates the CHANGELOG files for release ${{ github.event.release.tag_name }}"
        branch: changelog-${{ github.event.release.tag_name }} 
        base: main 
        delete-branch: true
        labels: changelog