name: benchmarks

on: workflow_dispatch

permissions:
  contents: read

jobs:
  benchmark:

    runs-on: ubuntu-latest
    strategy:
      fail-fast: true
      matrix:
        versions:
          - ghc: '8.10.7'
            cabal: '3.2'
          - ghc: '9.2.2'
            cabal: '3.6'
    steps:
    - uses: actions/checkout@v6

    - name: Install cabal/ghc
      run: |
        ghcup install ghc --set ${{ matrix.versions.ghc }}
        ghcup install cabal ${{ matrix.versions.cabal }}

    # declare/restore cached things

    - name: Cache cabal global package db
      id:   cabal-global
      uses: actions/cache@v4
      with:
        path: |
          ~/.cabal
        key: benchmark-${{ runner.os }}-${{ matrix.versions.ghc }}-${{ matrix.versions.cabal }}-cabal-global-${{ secrets.CACHE_VERSION }}

    - name: Cache cabal work
      id:   cabal-local
      uses: actions/cache@v4
      with:
        path: |
          dist-newstyle
        key: benchmark-${{ runner.os }}-${{ matrix.versions.ghc }}-${{ matrix.versions.cabal }}-cabal-local-${{ secrets.CACHE_VERSION }}

    - name: Install dependencies
      run: |
          v2=$([ "${{ matrix.versions.cabal }}" = "2.2" ] && printf 'new' || printf 'v2')
          cabal $v2-update
          cabal $v2-build --dependencies-only --enable-optimization=1 --enable-benchmarks --disable-tests

    - name: Build and test
      run: |
          v2=$([ "${{ matrix.versions.cabal }}" = "2.2" ] && printf 'new' || printf 'v2')
          cabal $v2-build --enable-optimization=1 --enable-benchmarks --disable-tests 2>&1 | tee build.log
          # fail if warnings in local build
          ! grep -q ": *[Ww]arning:" build.log || exit 1
          cabal $v2-bench --enable-optimization=1 --benchmark-options='--timeout=6 +RTS -T -RTS'