name: coverage

on:
  push:
    branches: [main]
    paths:
      - "rs/**"
      - ".github/workflows/coverage.yml"
  pull_request:
    branches: [main]
    paths:
      - "rs/**"
      - ".github/workflows/coverage.yml"

jobs:
  coverage:
    name: cargo llvm-cov (capslockx-core)
    runs-on: ubuntu-latest
    env:
      # Floor that must not regress. Raise this number as coverage climbs.
      # Reflects current line% on capslockx-core --lib (excluding sherpa/test_platform).
      COVERAGE_FLOOR: "50"

    steps:
      - uses: actions/checkout@v4

      - name: Install system dependencies
        run: sudo apt-get update && sudo apt-get install -y libasound2-dev pkg-config

      - name: Install Rust stable
        uses: dtolnay/rust-toolchain@stable
        with:
          components: llvm-tools-preview

      - name: Cache Rust build artefacts
        uses: Swatinem/rust-cache@v2
        with:
          workspaces: rs -> rs/target

      - name: Install cargo-llvm-cov
        uses: taiki-e/install-action@cargo-llvm-cov

      - name: Run llvm-cov on capslockx-core
        working-directory: rs
        run: |
          cargo llvm-cov -p capslockx-core --lib \
            --no-fail-fast \
            --ignore-filename-regex '(sherpa|target/|test_platform)' \
            --json --output-path coverage.json
          cargo llvm-cov report \
            --ignore-filename-regex '(sherpa|target/|test_platform)' \
            --summary-only

      - name: Enforce coverage floor
        working-directory: rs
        run: |
          line_pct=$(python3 -c "
          import json
          d = json.load(open('coverage.json'))
          tot = d['data'][0]['totals']['lines']
          print(f\"{tot['percent']:.2f}\")")
          echo "Line coverage: ${line_pct}% (floor: ${COVERAGE_FLOOR}%)"
          python3 -c "
          import sys
          got = float('${line_pct}')
          floor = float('${COVERAGE_FLOOR}')
          if got < floor:
              print(f'::error::Coverage {got}% is below floor {floor}%')
              sys.exit(1)"

      - name: Upload coverage artifact
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: coverage-json
          path: rs/coverage.json