{
  config,
  pkgs,
  lib,
  ...
}: {
  programs = {
    # pantheon-tweaks.enable = true;
    evolution.enable = true;
  };

  services = {
    xserver = {
      enable = true;
      excludePackages = [pkgs.xterm];
      displayManager = {
        lightdm = {
          enable = true;
          greeters.pantheon.enable = true;
        };
      };

      desktopManager.pantheon = {
        enable = true;
        extraWingpanelIndicators = with pkgs; [
          monitor
          wingpanel-indicator-ayatana
        ];
      };

      xkb.layout = "us";

      updateDbusEnvironment = true;
    };

    # Enable touchpad support.
    libinput.enable = true;
  };

  systemd.user.services = {
    # monitor = {
    #   description = "indicator-monitor";
    #   wantedBy = [ "graphical-session.target" ];
    #   partOf = [ "graphical-session.target" ];
    #   serviceConfig = {
    #     ExecStart = "${pkgs.monitor}/bin/com.github.stsdc.monitor";
    #   };
    # };

    indicatorapp = {
      description = "indicator-application-gtk3";
      wantedBy = ["graphical-session.target"];
      partOf = ["graphical-session.target"];
      serviceConfig = {
        ExecStart = "${pkgs.indicator-application-gtk3}/libexec/indicator-application/indicator-application-service";
      };
    };
  };

  # App indicator
  environment.pathsToLink = ["/libexec"];
  environment.systemPackages = with pkgs; [
    gnome-online-accounts
    gnome-control-center
    gnome-system-monitor
    indicator-application-gtk3
    monitor
    pantheon-tweaks
    eog
  ];

  environment.pantheon.excludePackages = with pkgs.pantheon; [
    elementary-code
  ];
}