name: Validate Runner Determinator Script is in Sync

on:
  # Run on PRs when the runner-determinator script is updated to ensure it's copies are kept in sync
  pull_request:
    paths:
      - .github/workflows/_runner-determinator.yml
      - .github/workflows/runner-determinator-validator.yml
      - .github/scripts/runner_determinator.py
  workflow_dispatch:

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}-${{ github.event_name == 'workflow_dispatch' }}-${{ github.event_name == 'schedule' }}
  cancel-in-progress: true

jobs:
  check-runner-determinator:
    runs-on: ubuntu-latest

    steps:
    - name: Checkout repository
      uses: actions/checkout@v2

    - name: Run Hardcode runner-determinator script
      id: hardcode-script
      run: |
        # Extract the script content from _runner-determinator.yml and skip the first 10 spaces of each line
        script_content=$(awk '/cat <<EOF > runner_determinator.py/{flag=1;next}/EOF$/{flag=0}flag{print substr($0, 11)}' .github/workflows/_runner-determinator.yml)

        # Write the extracted script content to runner_determinator.py
        echo "$script_content" > runner_determinator_workflow.py

    - name: Compare runner-determinator script embedded in workflow with checked in script
      run: |
        # Compare the extracted runner_determinator script with the existing one
        # If this check fails, then make sure the contents of .github/scripts/runner_determinator.py is in sync with the
        # version embedded into .github/workflows/_runner-determinator.yml
        diff runner_determinator_workflow.py .github/scripts/runner_determinator.py
      # Fail the job if the scripts are not identical
      continue-on-error: false