# This workflow checks the code formatting of changed files in a pull request using clang-format.
# It is triggered on pull requests to the master branch.
# The workflow verifies that the clang-format version matches 18.1.8,
# checks formatting of modified files, and if formatting issues are found,
# creates a patch file that can be applied to fix the formatting.

name: Clang-Format Check

on:
  pull_request:
    branches:
      - '**'

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
  cancel-in-progress: true

jobs:
  format-check:
    name: Check code formatting
    runs-on: windows-2022

    steps:
    - name: Checkout repository
      uses: actions/checkout@v4.1.7
      with:
        fetch-depth: 0

    - name: Check clang-format version
      run: |
        $version = clang-format --version
        Write-Output "Detected clang-format version: $version"
        $version | Select-String "18.1.8" >$null
        if ($LASTEXITCODE -ne 0) {
          echo "::error::Wrong clang-format version. Expected 18.1.8"
          Write-Output "Error: Version mismatch - expected 18.1.8"
          exit 1
        }
      shell: pwsh

    - name: Get changed files
      id: changed-files
      run: |
        $changedFiles = git diff --name-only origin/${{ github.base_ref }} HEAD |
          Where-Object { $_ -match '^(src|tools)/' -and $_ -match '\.(cpp|hxx|cxx|lxx|h|pxx|hpp)$' }
        $changedFiles | Set-Content "changed_files.txt"
        if ($changedFiles.Count -gt 0) {
          echo "has_files=true" >> $env:GITHUB_OUTPUT
        }
      shell: pwsh

    - name: Check formatting
      id: check
      if: steps.changed-files.outputs.has_files == 'true'
      run: |
        $files = Get-Content "changed_files.txt"
        $files | ForEach-Object -ThrottleLimit 8 -Parallel {
          clang-format -i -style=file $_
        }
      shell: pwsh

    - name: Check git status
      id: git-check
      if: steps.changed-files.outputs.has_files == 'true'
      run: |
        git diff > format.patch
        if ((Get-Item format.patch).length -gt 0) {
          echo "has_changes=true" >> $env:GITHUB_OUTPUT
        }
      shell: pwsh

    - name: Upload patch
      if: steps.git-check.outputs.has_changes == 'true'
      uses: actions/upload-artifact@v4
      with:
        name: format-patch
        path: format.patch

    - name: Fail with instructions
      if: steps.git-check.outputs.has_changes == 'true'
      run: |
        echo "::error::Files need formatting. To fix: 1. Download format.patch 2. "git apply format.patch" 3. Commit and push"
        exit 1
      shell: pwsh