name: CI

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]

jobs:
  build-and-test:
    name: Build & Test
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v3

      - name: Install Rust (stable)
        uses: actions-rs/toolchain@v1
        with:
          toolchain: stable
          override: true

      - name: Build (release)
        run: cargo build --workspace --release

      - name: Run tests
        run: cargo test --all -- --nocapture

  coverage:
    name: Code Coverage (Tarpaulin)
    needs: build-and-test
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v3

      - name: Install Rust (nightly)
        uses: actions-rs/toolchain@v1
        with:
          toolchain: nightly
          override: true

      - name: Install tarpaulin prerequisites
        run: |
          rustup component add llvm-tools-preview

      - name: Install cargo-tarpaulin
        run: cargo install cargo-tarpaulin

      - name: Run coverage
        run: cargo tarpaulin --workspace --out Xml --fail-under 85

  benchmark:
    name: Performance Benchmark (Hyperfine)
    needs: build-and-test
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v3

      - name: Install Rust (stable)
        uses: actions-rs/toolchain@v1
        with:
          toolchain: stable
          override: true

      - name: Install benchmarking tools
        run: |
          sudo apt-get update
          sudo apt-get install -y hyperfine jq bc

      - name: Build release binary
        run: cargo build --release

      - name: Run cold-start benchmark
        run: |
          # measure cold start init latency
          hyperfine \
            --warmup 3 \
            --export-json perf.json \
            'target/release/marlin init'

      - name: Enforce P95 ≤ 3s
        run: |
          p95=$(jq '.results[0].percentiles["95.00"]' perf.json)
          echo "P95 init latency: ${p95}s"
          if (( $(echo "$p95 > 3.0" | bc -l) )); then
            echo "::error ::Performance threshold exceeded (P95 > 3.0s)"  
            exit 1
          fi