name: pre-commit

on:
  push:
  pull_request:
    branches: [main, dev]

jobs:
  pre-commit:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0  # Required for detecting diffs

      - name: Fetch main branch
        run: |
          # Ensure we have the main branch reference for comparison
          git fetch origin main:main 2>/dev/null || git fetch origin main 2>/dev/null || true

      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: '3.12'

      - name: Cache pre-commit environments
        uses: actions/cache@v4
        with:
          path: ~/.cache/pre-commit
          key: pre-commit-${{ hashFiles('.pre-commit-config.yaml') }}
          restore-keys: |
            pre-commit-

      - name: Install pre-commit
        run: |
          pip install pre-commit

      - name: Install hook environments (cache)
        run: |
          pre-commit install-hooks

      - name: Run pre-commit on changed files
        run: |
          # Use pre-commit's native diff detection with fallback strategies
          if git show-ref --verify --quiet refs/heads/main; then
            # Main branch exists locally, use pre-commit's native diff mode
            echo "Running pre-commit with native diff detection against main branch"
            pre-commit run --from-ref main --to-ref HEAD
          elif git show-ref --verify --quiet refs/remotes/origin/main; then
            # Origin/main exists, use it as reference
            echo "Running pre-commit with native diff detection against origin/main"
            pre-commit run --from-ref origin/main --to-ref HEAD
          else
            # Fallback: run on all files (for first commits or when main is unavailable)
            echo "Main branch reference not found, running pre-commit on all files"
            echo "⚠️  This may take longer and show more issues than normal"
            pre-commit run --all-files
          fi