license-headers.yml

name: License headers

on:
  pull_request:
    paths:
      - "backend/**/*.py"
      - "frontend/src/**/*.ts"
      - "frontend/src/**/*.vue"
      - "multiplayer/src/**/*.ts"
      - "shared/**/*.ts"
      - ".github/workflows/license-headers.yml"

permissions:
  contents: read

jobs:
  check-headers:
    name: Apache-2.0 header on new source files
    runs-on: ubuntu-latest
    timeout-minutes: 3
    env:
      BASE_SHA: ${{ github.event.pull_request.base.sha }}
      HEAD_SHA: ${{ github.event.pull_request.head.sha }}
    steps:
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0

      - name: Find new / changed source files
        id: changed
        run: |
          set -euo pipefail
          # Source files only; skip generated/vendored trees.
          mapfile -t files < <(git diff --name-only --diff-filter=AM "$BASE_SHA" "$HEAD_SHA" \
            | grep -E '^(backend/.*\.py|frontend/src/.*\.(ts|vue)|multiplayer/src/.*\.ts|shared/.*\.ts)$' \
            | grep -v -E '(__pycache__|node_modules|dist|build|alembic/versions)' \
            || true)
          printf '%s\n' "${files[@]}" > changed_files.txt
          echo "count=${#files[@]}" >> "$GITHUB_OUTPUT"

      - name: Verify Apache 2.0 header
        if: steps.changed.outputs.count != '0'
        run: |
          set -euo pipefail
          missing=0
          while IFS= read -r f; do
            [ -z "$f" ] && continue
            if ! head -n 15 "$f" | grep -q "Licensed under the Apache License, Version 2.0"; then
              echo "::error file=$f::missing Apache 2.0 license header"
              missing=$((missing + 1))
            fi
          done < changed_files.txt
          if [ "$missing" -gt 0 ]; then
            echo ""
            echo "Files missing the Apache 2.0 header: $missing"
            echo "Add the header from an existing file (e.g. backend/app/main.py) to the top of each new source file."
            exit 1
          fi