name: Main Promotion

on:
  pull_request:
    branches: [main]
    types: [opened, synchronize, reopened, ready_for_review, edited]

permissions:
  contents: read

jobs:
  source-branch:
    name: Require dev source
    runs-on: ubuntu-latest
    steps:
      - name: Reject non-dev promotions
        env:
          BASE_BRANCH: ${{ github.base_ref }}
          HEAD_BRANCH: ${{ github.head_ref }}
          HEAD_REPOSITORY: ${{ github.event.pull_request.head.repo.full_name }}
          REPOSITORY: ${{ github.repository }}
        run: |
          if [ "$BASE_BRANCH" != "main" ] \
             || [ "$HEAD_BRANCH" != "dev" ] \
             || [ "$HEAD_REPOSITORY" != "$REPOSITORY" ]; then
            echo "::error::main only accepts pull requests from this repository's dev branch. Open feature work against dev first, then promote dev to main."
            exit 1
          fi
          echo "Verified $HEAD_REPOSITORY:$HEAD_BRANCH → $BASE_BRANCH"