let
  inputs = import ./npins;
  system = "x86_64-linux";
  pkgs = import inputs.nixpkgs { config = { }; overlays = [ ]; system = builtins.currentSystem; };
  lib = import "${inputs.nixpkgs}/lib" // { inherit nixosSystem; };
  nixosSystem = args:
    import "${inputs.nixpkgs}/nixos/lib/eval-config.nix"
      (
        {
          inherit lib;
          # Allow system to be set modularly in nixpkgs.system.
          # We set it to null, to remove the "legacy" entrypoint's
          # non-hermetic default.
          system = null;

          modules = args.modules;
        }
        // builtins.removeAttrs args [ "modules" ]
      );
in
rec {
  nixosModules = {
    disko = "${inputs.disko}/module.nix";
    disk-layout = import ./vm/disk-layout.nix;
    interactive-vm = import ./vm/interactive-vm.nix;
    mastodon-vm = import ./vm/mastodon-vm.nix;
    peertube-vm = import ./vm/peertube-vm.nix;
    pixelfed-vm = import ./vm/pixelfed-vm.nix;
  };

  # test with
  #     nix-build -A nixosConfigurations.<config>.installTest
  nixosConfigurations = {
    mastodon = nixosSystem {
      inherit system;
      modules = with nixosModules; [
        disko
        disk-layout
        interactive-vm
        mastodon-vm
      ];
    };

    peertube = nixosSystem {
      inherit system;
      modules = with nixosModules; [
        disko
        disk-layout
        interactive-vm
        peertube-vm
      ];
    };

    pixelfed = nixosSystem {
      inherit system;
      modules = with nixosModules; [
        disko
        disk-layout
        interactive-vm
        pixelfed-vm
      ];
    };

    all = nixosSystem {
      inherit system;
      modules = with nixosModules; [
        interactive-vm
        disko
        disk-layout
        peertube-vm
        pixelfed-vm
        mastodon-vm
      ];
    };
  };

  # build with
  #     nix-build -A installers.<config>
  installers =
    let
      installer = (import ./installer.nix) { inherit lib; outPath = inputs.nixpkgs; };
    in
    lib.mapAttrs (_: config: installer config) nixosConfigurations;

  # run with
  #     $(nix-build -A deploy.<machine> --no-out-link)/bin/deploy
  deploy =
    let
      deployCommand = (pkgs.callPackage ./deploy.nix { });
    in
    lib.mapAttrs (name: config: deployCommand name config) nixosConfigurations;

  tests = {
    mastodon-garage = import ./tests/mastodon-garage.nix { inherit pkgs; };
    pixelfed-garage = import ./tests/pixelfed-garage.nix { inherit pkgs; };
  };

  shell = pkgs.mkShell {
    packages = with pkgs; [
      nil
    ];
  };
}