name: Build & Test

on:
  push:
    branches:
      - main
  pull_request:
  workflow_dispatch:

jobs:
  test:
    name: Run Swift Tests (${{ matrix.name }})
    runs-on: macos-latest
    # A hung test must fail fast, not hold a runner for GitHub's 360-minute
    # default (observed: intermittent app-suite hangs starving the queue).
    timeout-minutes: 15

    strategy:
      fail-fast: false # Don't cancel other matrix jobs when one fails
      matrix:
        include:
          - name: app
            path: .
          - name: BitLogger
            path: localPackages/BitLogger
          - name: BitFoundation
            path: localPackages/BitFoundation

    steps:
      - name: Checkout code
        uses: actions/checkout@v5

      - name: Compute Swift cache salt
        id: swift_cache_salt
        run: |
          {
            swift --version
            xcrun --show-sdk-platform-path
            xcrun --show-sdk-version
            xcodebuild -version
          } | shasum -a 256 | awk '{ print "value=" $1 }' >> "$GITHUB_OUTPUT"

      - name: Cache build artifacts
        uses: actions/cache@v4
        with:
          path: ${{ matrix.path }}/.build
          key: ${{ runner.os }}-${{ runner.arch }}-${{ matrix.name }}-${{ steps.swift_cache_salt.outputs.value }}-${{ hashFiles(format('{0}/**/*.swift', matrix.path), format('{0}/**/Package.resolved', matrix.path)) }}
          restore-keys: |
            ${{ runner.os }}-${{ runner.arch }}-${{ matrix.name }}-${{ steps.swift_cache_salt.outputs.value }}-${{ hashFiles(format('{0}/**/Package.resolved', matrix.path)) }}
            ${{ runner.os }}-${{ runner.arch }}-${{ matrix.name }}-${{ steps.swift_cache_salt.outputs.value }}-

      - name: Build tests
        # Built separately so the hang watchdog below times only test
        # execution: a cold-cache coverage build on a slow runner can
        # legitimately take several minutes, and is already bounded by the
        # 15-minute job timeout.
        run: swift build --build-tests --enable-code-coverage --package-path ${{ matrix.path }}

      - name: Run Tests
        # Perf benchmarks are excluded here and run in their own serial step
        # below: measuring while parallel test processes contend for cores
        # produces noisy numbers, and the XCTest measure machinery has hung
        # intermittently under parallel workers on loaded runners. Excluded
        # via --skip (not just the env guard): every app run since the
        # baselines landed timed out at the 15-minute job limit with the
        # baseline tests dispatched into the parallel phase.
        #
        # The watchdog samples any still-running test processes after 5
        # minutes (the suite passes in seconds when healthy; the build is
        # done by this step) and kills the run, so a hang fails fast with
        # stacks in the log instead of a silent timeout.
        env:
          BITCHAT_SKIP_PERF_BASELINES: "1"
        run: |
          swift test --skip-build --parallel --quiet --enable-code-coverage \
            --skip PerformanceBaselineTests \
            --package-path ${{ matrix.path }} &
          test_pid=$!
          (
            sleep 300
            if kill -0 "$test_pid" 2>/dev/null; then
              echo "::group::Tests still running after 5 minutes — sampling before kill"
              for pid in $(pgrep -if 'swiftpm-testing|xctest|PackageTests' || true); do
                echo "--- sample of pid $pid ---"
                sample "$pid" 5 2>/dev/null || true
              done
              echo "::endgroup::"
              pkill -KILL -P "$test_pid" 2>/dev/null || true
              kill -KILL "$test_pid" 2>/dev/null || true
            fi
          ) &
          watchdog_pid=$!
          wait "$test_pid" && status=0 || status=$?
          kill "$watchdog_pid" 2>/dev/null || true
          exit "$status"

      # Benchmarks run serially on an otherwise idle runner for stable
      # numbers; BITCHAT_PERF_LOG captures the PERF[...] lines for the gate.
      - name: Run performance benchmarks (serial)
        if: matrix.name == 'app'
        timeout-minutes: 6
        env:
          BITCHAT_PERF_LOG: ${{ github.workspace }}/perf-output.log
        run: swift test --quiet --filter PerformanceBaselineTests

      # Order-of-magnitude performance regression gate. Floors are deliberately
      # generous (see bitchatTests/Performance/perf-floors.json) so this
      # catches algorithmic regressions, never runner variance.
      - name: Performance floor gate
        if: matrix.name == 'app'
        run: ./scripts/check-perf-floors.sh perf-output.log

      # Informational only: surfaces per-file and total line coverage in the
      # job log so coverage trends are visible on every PR. No thresholds —
      # this must never be the reason a build goes red.
      - name: Coverage summary
        run: |
          BIN_PATH=$(swift build --show-bin-path --package-path ${{ matrix.path }})
          PROF="$BIN_PATH/codecov/default.profdata"
          XCTEST=$(find "$BIN_PATH" -maxdepth 1 -name '*.xctest' | head -1)
          BINARY="$XCTEST/Contents/MacOS/$(basename "$XCTEST" .xctest)"
          if [ -f "$PROF" ] && [ -f "$BINARY" ]; then
            xcrun llvm-cov report "$BINARY" -instr-profile "$PROF" \
              -ignore-filename-regex='(Tests|\.build|checkouts|Mocks|_PreviewHelpers)' || true
          else
            echo "No coverage data found; skipping summary."
          fi

  # SPM tests above only compile the macOS slice; this job covers the
  # iOS-conditional code paths (UIKit, CoreBluetooth restoration, etc.).
  ios-build:
    name: Build iOS app (simulator)
    runs-on: macos-latest
    timeout-minutes: 15

    steps:
      - name: Checkout code
        uses: actions/checkout@v5

      - name: Build iOS (simulator, no signing)
        # arm64 only: the vendored arti.xcframework has no x86_64 simulator slice.
        run: |
          set -o pipefail
          xcodebuild -project bitchat.xcodeproj \
            -scheme "bitchat (iOS)" \
            -sdk iphonesimulator \
            -destination 'generic/platform=iOS Simulator' \
            ARCHS=arm64 \
            CODE_SIGNING_ALLOWED=NO \
            build