name: CI

on:
  push:
  pull_request:

# nix flake check evaluates every host in one process (~19 GB peak), more than
# the 16 GB RAM of ubuntu-latest. One job per check keeps the peak at the
# largest single host and shows failing hosts in the run overview.
jobs:
  list:
    runs-on: ubuntu-latest
    outputs:
      checks: ${{ steps.list.outputs.checks }}
    steps:
      - uses: actions/checkout@v4
        with:
          # Fetch all history for git-based operations
          fetch-depth: 0

      - uses: cachix/install-nix-action@v31

      - id: list
        run: |
          checks=$(nix eval --json .#checks.x86_64-linux --apply builtins.attrNames)
          echo "checks=$checks" >> "$GITHUB_OUTPUT"

  check:
    needs: list
    name: ${{ matrix.check }}
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        check: ${{ fromJSON(needs.list.outputs.checks) }}
    steps:
      - uses: actions/checkout@v4
        with:
          # Fetch all history for git-based operations
          fetch-depth: 0

      - uses: cachix/install-nix-action@v31

      - run: nix build -L --no-link '.#checks.x86_64-linux.${{ matrix.check }}'

  outputs:
    name: packages and devShells
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          # Fetch all history for git-based operations
          fetch-depth: 0

      - uses: cachix/install-nix-action@v31

      - run: |
          for output in packages devShells; do
            echo "$output:"
            # shellcheck disable=SC2016 # ${...} is Nix interpolation
            nix eval --raw ".#$output.x86_64-linux" --apply 'xs: builtins.deepSeq (builtins.mapAttrs (_: x: x.drvPath) xs) "${toString (builtins.length (builtins.attrNames xs))} evaluated\n"'
          done