{ lib, ... }:
let
  userOptions =
    with lib;
    with types;
    { config, ... }:
    {
      options.email = mkOption {
        type = nullOr str;
        description = "Email address of the user.";
      };

      options.fullName = mkOption {
        type = nullOr str;
        description = "Full name of the user.";
      };
    };
in
{
  options =
    with lib;
    with types;
    {
      users.users = mkOption { type = attrsOf (submodule userOptions); };
    };
}