nixos/mosh: use `mkEnableOption`

{ config, lib, pkgs, ... }:

with lib;

let

  cfg  = config.programs.mosh;

in

{

  options.programs.mosh = {

    enable = mkOption {

      description = lib.mdDoc ''

        Whether to enable mosh. Note, this will open ports in your firewall!

      '';

      default = false;

      type = lib.types.bool;

    };

    withUtempter = mkOption {

    enable = lib.mkEnableOption "mosh";

    withUtempter = lib.mkEnableOption "" // {

      description = lib.mdDoc ''

        Whether to enable libutempter for mosh.

        This is required so that mosh can write to /var/run/utmp (which can be queried with `who` to display currently connected user sessions).

        Note, this will add a guid wrapper for the group utmp!

      '';

      default = true;

      type = lib.types.bool;

    };

  };

  config = mkIf cfg.enable {

    environment.systemPackages = with pkgs; [ mosh ];

  config = lib.mkIf cfg.enable {

    environment.systemPackages = [ pkgs.mosh ];

    networking.firewall.allowedUDPPortRanges = [ { from = 60000; to = 61000; } ];

    security.wrappers = mkIf cfg.withUtempter {

    security.wrappers = lib.mkIf cfg.withUtempter {

      utempter = {

        source = "${pkgs.libutempter}/lib/utempter/utempter";

        owner = "root";