name: Format Check

on:
  push:
    paths: &workflow_paths
      - '**.cpp'
      - '**.h'
      - '**.c'
      - '**.cc'
      - '**.cxx'
      - '**.hh'
      - '**.hpp'
      - '**.hxx'
      - '**.inl'
      - '.clang-format'
      - '.github/workflows/clang-format.yml'
      - '.github/scripts/check-clang-format.sh'

  pull_request:
    paths: *workflow_paths

  workflow_dispatch:

jobs:
  clang-format:
    runs-on: ubuntu-latest
    concurrency:
      group: clang-format-${{ github.ref }}
      cancel-in-progress: true
    steps:
      - name: Checkout repository
        uses: actions/checkout@v6
        with:
          fetch-depth: 2

      - name: Install clang-format
        uses: daaku/gh-action-apt-install@v4
        with:
          packages: clang-format

      - name: Check changed files
        env:
          CLANG_FORMAT_BIN: clang-format
          EVENT_NAME: ${{ github.event_name }}
          PR_BASE_REF: ${{ github.event.pull_request.base.ref }}
          PR_BASE_SHA: ${{ github.event.pull_request.base.sha }}
          BEFORE_SHA: ${{ github.event.before }}
          CURRENT_SHA: ${{ github.sha }}
        run: |
          set -euo pipefail

          BASE_SHA=""
          if [ "$EVENT_NAME" = "pull_request" ]; then
            git fetch --no-tags origin "$PR_BASE_REF"
            BASE_SHA="$(git merge-base "origin/$PR_BASE_REF" "$CURRENT_SHA")"
          elif [ -n "$BEFORE_SHA" ] && [ "$BEFORE_SHA" != "0000000000000000000000000000000000000000" ]; then
            BASE_SHA="$BEFORE_SHA"
          fi

          bash ./.github/scripts/check-clang-format.sh "$BASE_SHA" "$CURRENT_SHA"