name: Tests

on:
  push:
    branches: [master, main]
    paths:
      - 'backend/**'
      - 'exam-app/**'
      - 'requirements*.txt'
      - '.github/workflows/test.yml'
  pull_request:
    branches: [master, main]
    paths:
      - 'backend/**'
      - 'exam-app/**'
      - 'requirements*.txt'

jobs:
  # ── Backend unit + integration tests ────────────────────────────────────────
  backend-tests:
    name: Backend Tests (Python ${{ matrix.python-version }})
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        python-version: ["3.12"]

    steps:
      - uses: actions/checkout@v4

      - name: Set up Python ${{ matrix.python-version }}
        uses: actions/setup-python@v5
        with:
          python-version: ${{ matrix.python-version }}
          cache: pip

      - name: Install dependencies
        run: |
          pip install -r requirements.txt
          pip install -r requirements-dev.txt

      - name: Run fast test suite (no live AI, no fault injection)
        env:
          ANTHROPIC_AUTH_TOKEN: test-token-ci
          JWT_SECRET: ${{ secrets.JWT_SECRET || 'ci-test-secret-at-least-32-chars-long' }}
          ADMIN_KEY: ci-admin-key
          ADMIN_MASTER_SECRET: ""
          SQLITE_PATH: ":memory:"
        run: |
          PYTHONPATH=backend python3 -m pytest backend/tests/ \
            -m "not live_ai and not fault_injection" \
            --tb=short \
            -q \
            --randomly-seed=0 \
            -x

      - name: Run fault injection tests
        env:
          ANTHROPIC_AUTH_TOKEN: test-token-ci
          JWT_SECRET: ${{ secrets.JWT_SECRET || 'ci-test-secret-at-least-32-chars-long' }}
          ADMIN_KEY: ci-admin-key
          ADMIN_MASTER_SECRET: ""
          SQLITE_PATH: ":memory:"
        run: |
          PYTHONPATH=backend python3 -m pytest backend/tests/ \
            -m "fault_injection" \
            --tb=short \
            -q
        continue-on-error: true   # fault injection is informational until stabilised

  # ── Frontend unit tests ──────────────────────────────────────────────────────
  frontend-tests:
    name: Frontend Tests (Node ${{ matrix.node-version }})
    runs-on: ubuntu-latest
    strategy:
      matrix:
        node-version: ["20"]

    defaults:
      run:
        working-directory: exam-app

    steps:
      - uses: actions/checkout@v4

      - name: Set up Node ${{ matrix.node-version }}
        uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node-version }}
          cache: npm
          cache-dependency-path: exam-app/package-lock.json

      - name: Install dependencies
        run: npm ci

      - name: Run Vitest unit tests
        run: npm test

  # ── Mutation score gate (weekly, manual, or on demand) ───────────────────────
  mutation-score:
    name: Mutation Score Gate
    runs-on: ubuntu-latest
    if: github.event_name == 'workflow_dispatch' || github.event.schedule != ''
    # Run manually via: gh workflow run test.yml
    # Or add to a scheduled cron job by uncommenting below:
    # on:
    #   schedule:
    #     - cron: '0 3 * * 1'  # Monday 03:00 UTC

    steps:
      - uses: actions/checkout@v4

      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
          cache: pip

      - name: Install dependencies
        run: |
          pip install -r requirements.txt
          pip install -r requirements-dev.txt

      - name: Run mutation testing
        env:
          ANTHROPIC_AUTH_TOKEN: test-token-ci
          JWT_SECRET: ci-test-secret-at-least-32-chars-long
          ADMIN_KEY: ci-admin-key
          ADMIN_MASTER_SECRET: ""
        run: |
          PYTHONPATH=backend mutmut run \
            --paths-to-mutate backend/app/agent/ \
            --tests-dir backend/tests/ \
            || true  # mutmut exits non-zero when mutations survive — handled below

      - name: Check mutation score gate
        run: |
          PYTHONPATH=backend python3 tools/check_mutation_score.py --min 70