{ inputs, self, ... }: {
  imports = [ (inputs.helpers.mkMirroredModulesFlakeModule "globalOptions" ({ lib, ... }: {
    options.features.shells.defaultShell = lib.mkOption {
      type = inputs.helpers.mkEnumFromDirContents "${self}/modules/features/shells";
      description = "This option controls the shell that should be used as the default, enabling that shell in the process.";
      default = "zsh";
    };
  })) ];

  flake.nixosModules.global = { config, pkgs, lib, ... }: {
    programs.${config.features.shells.defaultShell}.enable = true;

    users.defaultUserShell = pkgs.${config.features.shells.defaultShell};
    users.users."grey".shell = pkgs.${config.features.shells.defaultShell};
  };
}