{ config, lib, ... }:

let cfg = config.local.programs.calendar; in
{
  options.local.programs.calendar.khal = {
    enable = lib.mkEnableOption "khal";

    # Custom package doesn't work yet.
    # See: https://github.com/nix-community/home-manager/pull/5428 
    # package = lib.mkPackageOption pkgs "khal" { };
  };

  config = {
    programs.khal = lib.mkIf cfg.khal.enable {
      enable = true;
      locale = rec {
        timeformat = "%H:%M";
        dateformat = "%d.%m.";
        longdateformat = "%d.%m.%Y";
        datetimeformat = "${dateformat} ${timeformat}";
        longdatetimeformat = "${longdateformat} ${timeformat}";
      };
      # See: https://khal.readthedocs.io/en/latest/configure.html 
      settings = { };
    };
  };
}