nixos-config/modules/common/users.nix

{ lib, config, ... }:
with lib;
let
  userModule = types.submodule {
    options = {
      description = mkOption { type = types.str; };

      groups = mkOption { type = types.listOf types.str; };

      uid = mkOption { type = types.nullOr types.int; };

      shell = mkOption { type = types.package; };

      hmConfig = mkOption { default = { }; };
    };
  };
in
{
  options.my.users = mkOption { type = types.attrsOf userModule; };

  config = {
    users.users = builtins.mapAttrs (name: value: {
      isNormalUser = true;
      home = "/home/${name}";
      description = value.description;
      extraGroups = value.groups;
      shell = value.shell;
      uid = mkIf (value.uid != null) value.uid;
    }) config.my.users;
  };
}