name: pre-commit

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

jobs:
  # mypy and pylint check the whole repo and are the two slowest hooks, so
  # each gets its own runner and the other hooks share a third; the workflow
  # takes as long as the slowest group rather than the sum.
  pre-commit:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        include:
          - group: mypy
            hooks: mypy
            skip: ""
          - group: pylint
            hooks: pylint
            skip: ""
          # free-days-interop needs Flutter and the freedays venv; it runs as
          # its own job in python-tests.yml, so skipping it here is not
          # fail-open.
          - group: rest
            hooks: ""
            skip: mypy,pylint,free-days-interop
    name: pre-commit (${{ matrix.group }})
    steps:
      - uses: actions/checkout@v4

      # Two hooks here delegate to the shared gates in kuhyx/utils. Without
      # this checkout they exit 1 with "shared gate not found at
      # /home/runner/utils/..." -- which is what this workflow had been doing
      # on every run since those hooks were added.
      - name: Check out the shared gates
        uses: actions/checkout@v4
        with:
          repository: kuhyx/utils
          path: .utils
      - name: Point the delegates at that checkout
        run: echo "UTILS_ROOT=$GITHUB_WORKSPACE/.utils" >> "$GITHUB_ENV"

      - uses: actions/setup-python@v5
        with:
          python-version: "3.x"
      - uses: astral-sh/setup-uv@v10.2.0

      # Every hook brings its own environment except the language: system
      # ones; of those only dependency-freshness imports third-party code
      # (pyyaml, packaging). The whole requirements.txt used to be installed
      # here for nothing -- 28 s of a 60 s run.
      - name: Install pre-commit and the system hooks' imports
        run: uv pip install --system pre-commit pyyaml packaging

      # One cache per group: a shared key would hold whichever group saved
      # first, and the others would rebuild their hook envs on every run. The
      # restore key lets a config change reuse every env whose rev it kept.
      - uses: actions/cache@v4
        with:
          path: ~/.cache/pre-commit
          key: pre-commit-${{ matrix.group }}-${{ env.pythonLocation }}-${{ hashFiles('.pre-commit-config.yaml') }}
          restore-keys: pre-commit-${{ matrix.group }}-${{ env.pythonLocation }}-

      - name: pre-commit run (${{ matrix.group }})
        env:
          SKIP: ${{ matrix.skip }}
        run: pre-commit run ${{ matrix.hooks }} --all-files --show-diff-on-failure --color=always