name: Migration Drift Check
on:
  pull_request:
  push:
    branches: [master]
jobs:
  drift:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - name: Install deps
        run: |
          python -m pip install --upgrade pip
          pip install -r modern/backend/requirements.txt
      - name: Generate revision (dry run)
        working-directory: modern
        run: |
          # use a temp alembic dir to detect changes
          alembic -c backend/alembic.ini revision --autogenerate -m "drift-check" || true
          # If a new file appears in versions with drift-check, fail
          if ls backend/alembic/versions | grep -q "drift-check"; then
            echo "Model changes detected without migration. Please create an Alembic migration."
            exit 1
          fi