builder.nix

{ nixpkgs, home-manager, machines, userName, secrets, system, pkgs, inputs }:
let
  commonSpecialArgs = { inherit userName secrets machines inputs system; };
  homeModules = [ ./home ];
  nixModules = [ ./nix ];
  stateVersion = "22.05";
  lib = nixpkgs.lib;
in
{
  nixosConfigurations =
    builtins.mapAttrs
      (hostName: opts:
        let
          user = {
            imports = homeModules ++ opts.homeModules;
            home = { inherit stateVersion; };
            programs.home-manager.enable = true;
          };
        in
        {
          nixConfig = {
            extra-substituters = [ ];
          };
        } //
        lib.nixosSystem
          (
            let specialArgs = commonSpecialArgs // { inherit hostName opts; };
            in
            {
              inherit specialArgs;
              modules = nixModules ++ opts.nixModules ++
              [{ system = { inherit stateVersion; }; }
                home-manager.nixosModules.home-manager
                {
                  home-manager = {
                    extraSpecialArgs = specialArgs;
                    sharedModules = [];
                    useGlobalPkgs = true;
                    useUserPackages = true;
                    users = {
                      root = user;
                      ${userName} = user;
                    };
                  };
                }];
            }
          )
      )
      machines;
  homeConfigurations.${userName} =
    home-manager.lib.homeManagerConfiguration
      {
        inherit pkgs;
        extraSpecialArgs = commonSpecialArgs //
          {
            hostName = "";
            wifi.enable = false;
          };
        modules = homeModules ++
          # some options seem to be required only for standalone home-manager
          [{
            home =
              {
                username = userName;
                homeDirectory = "/home/${userName}";
                inherit stateVersion;
              };
          }];
      };
}