{
  pkgs,
  lib,
  options,
  config,
  inputs,
  ...
}: let
  inherit (lib) types mkOption mkDefault foldl optionalAttrs;

  cfg = config.snowfallorg;

  user-names = builtins.attrNames cfg.user;

  create-system-users = system-users: name: let
    user = cfg.user.${name};
  in
    system-users
    // (optionalAttrs user.create {
      ${name} = {
        home = mkDefault user.home.path;
        isHidden = mkDefault false;
      };
    });
in {
  options.snowfallorg = {
    user = mkOption {
      description = "User configuration.";
      default = {};
      type = types.attrsOf (types.submodule ({name, ...}: {
        options = {
          create = mkOption {
            description = "Whether to create the user automatically.";
            type = types.bool;
            default = true;
          };

          home = {
            enable = mkOption {
              type = types.bool;
              default = true;
            };

            path = mkOption {
              type = types.str;
              default = "/Users/${name}";
            };

            config = mkOption {
              # HM-compatible options taken from:
              # https://github.com/nix-community/home-manager/blob/0ee5ab611dc1fbb5180bd7d88d2aeb7841a4d179/nixos/common.nix#L14
              type = types.submoduleWith {
                specialArgs =
                  {
                    osConfig = config;
                    modulesPath = "${inputs.home-manager}/modules";
                  }
                  // config.home-manager.extraSpecialArgs;
                modules =
                  [
                    ({
                      lib,
                      modulesPath,
                      ...
                    }: {
                      imports = import "${modulesPath}/modules.nix" {
                        inherit pkgs lib;
                        useNixpkgsModule = !config.home-manager.useGlobalPkgs;
                      };

                      config = {
                        submoduleSupport.enable = true;
                        submoduleSupport.externalPackageInstall = cfg.useUserPackages;

                        home.username = config.users.users.${name}.name;
                        home.homeDirectory = config.users.users.${name}.home;

                        nix.package = config.nix.package;
                      };
                    })
                  ]
                  ++ config.home-manager.sharedModules;
              };
            };
          };
        };
      }));
    };
  };

  config = {
    users.users = foldl create-system-users {} user-names;
  };
}