name: Semantic Pull Request

on:
  pull_request_target:
    types:
      - opened
      - reopened
      - edited
      - synchronize

permissions:
  pull-requests: write

jobs:
  validate:
    name: Validate PR title
    runs-on: ubuntu-latest
    steps:
      - name: Check PR title
        uses: amannn/action-semantic-pull-request@48f256284bd46cdaab1048c3721360e808335d50 # v6
        id: lint_pr_title
        with:
          subjectPattern: ^(?![A-Z]).+$ # Ensure the subject doesn't start with an uppercase character
          subjectPatternError: |
            The subject "{subject}" found in the pull request title "{title}"
            didn't match the configured pattern. Please ensure that the subject
            doesn't start with an uppercase character.
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Comment on invalid PR title
        uses: marocchino/sticky-pull-request-comment@70d2764d1a7d5d9560b100cbea0077fc8f633987 # v3
        # NOTE: null comparison is intentional per official README
        if: always() && (steps.lint_pr_title.outputs.error_message != null)
        with:
          header: pr-title-lint-error
          message: |
            Thanks for your contribution!

            PR titles need to follow [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/) format. It looks like your title needs a small adjustment.

            *Hint:*

            ```
            ${{ steps.lint_pr_title.outputs.error_message }}
            ```

      - name: Remove comment on valid PR title
        uses: marocchino/sticky-pull-request-comment@70d2764d1a7d5d9560b100cbea0077fc8f633987 # v3
        # NOTE: null comparison is intentional per official README
        if: ${{ steps.lint_pr_title.outputs.error_message == null }}
        with:
          header: pr-title-lint-error
          delete: true