# cSpell:words amannn marocchino
name: Semantic Pull Request

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

permissions: {}

jobs:
  validate:
    name: Validate PR title
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - name: Generate App Token
        id: app-token
        uses: actions/create-github-app-token@f8d387b68d61c58ab83c6c016672934102569859 # v3.0.0
        if: vars.RELEASE_APP_ID != ''
        with:
          app-id: ${{ vars.RELEASE_APP_ID }}
          private-key: ${{ secrets.RELEASE_APP_PRIVATE_KEY }}

      - 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: ${{ steps.app-token.outputs.token || secrets.GITHUB_TOKEN }}

      # Block breaking changes (feat!, fix!, etc.) on PRs targeting main
      - name: Block breaking changes on main
        if: >
          github.event.pull_request.base.ref == 'main' &&
          steps.lint_pr_title.outputs.error_message == null
        env:
          PR_TITLE: ${{ github.event.pull_request.title }}
        run: |
          if echo "$PR_TITLE" | grep -qE '^[a-z]+(\(.+\))?!:'; then
            echo "::error::Breaking changes (indicated by '!' in the PR title) are not allowed on main."
            echo "::error::Please target the 'next' branch for breaking changes."
            exit 1
          fi

      - 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
          GITHUB_TOKEN: ${{ steps.app-token.outputs.token || secrets.GITHUB_TOKEN }}
          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
          GITHUB_TOKEN: ${{ steps.app-token.outputs.token || secrets.GITHUB_TOKEN }}
          delete: true