name: "Build"
on:
  pull_request:

jobs:
  determine_hosts:
    name: "Determining hosts to build"
    runs-on: ubuntu-latest
    container:
      image: catthehacker/ubuntu:act-latest

    steps:
      - uses: actions/checkout@v5
      - uses: https://github.com/cachix/install-nix-action@v31
        with:
          nix_path: nixpkgs=channel:nixos-unstable
      - name: "List hosts"
        id: hosts
        run: |
          hosts="$(nix eval .#nixosConfigurations --apply builtins.attrNames --json)"
          echo "hostnames=${hosts}" >> "$GITHUB_OUTPUT"
    outputs:
      hosts: ${{ steps.hosts.outputs.hostnames }}

  build:
    runs-on: ubuntu-latest
    container:
      image: catthehacker/ubuntu:act-latest
    needs: determine_hosts
    strategy:
      matrix:
        hostname: ${{ fromJSON(needs.determine_hosts.outputs.hosts) }}

    steps:
      - uses: actions/checkout@v5
      - uses: https://github.com/cachix/install-nix-action@v31
        with:
          nix_path: nixpkgs=channel:nixos-unstable
      - name: "Define host"
        env:
          hostname: ${{ matrix.hostname }}
        run: |
          echo "Hostname: ${{ matrix.hostname }}"
      - run: |
          nixos-rebuild build --flake ".#${hostname}"