name: Gitignore formatting

on:
  pull_request:
  workflow_dispatch:

permissions:
  contents: read

jobs:
  formatting:
    name: Check gitignore formatting
    runs-on: ubuntu-latest
    timeout-minutes: 5

    steps:
      - name: Check out repository
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        with:
          persist-credentials: false

      - name: Set up Python
        uses: actions/setup-python@6d4fd22b20465ccc0f7354476588e8df7c9ca0e0 # v7.1.0
        with:
          python-version: "3.15.2"

      - name: Install formatting tools
        run: python -m pip install pre-commit-hooks==6.0.0

      - name: Install dos2unix
        run: |
          sudo apt-get update
          sudo apt-get install --yes dos2unix

      - name: Check all gitignore files recursively
        shell: bash
        run: |
          git ls-files -z -- ':(top,glob)**/*.gitignore' > "$RUNNER_TEMP/gitignore-files"
          mapfile -d '' -t files < "$RUNNER_TEMP/gitignore-files"

          if (( ${#files[@]} == 0 )); then
            echo "::error::No gitignore files found."
            exit 1
          fi

          echo "Checking ${#files[@]} gitignore files."

          status=0
          if ! dos2unix --keep-bom -- "${files[@]}" > "$RUNNER_TEMP/dos2unix.log" 2>&1; then
            cat "$RUNNER_TEMP/dos2unix.log" >&2
            status=1
          fi
          trailing-whitespace-fixer -- "${files[@]}" || status=1
          end-of-file-fixer -- "${files[@]}" || status=1

          git --no-pager diff --no-ext-diff --exit-code -- "${files[@]}" || status=1

          if (( status != 0 )); then
            echo "::error::Formatting checks failed. See tool output and diff above."
          fi

          exit "$status"