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

with lib;

let
  cfg = config.gnome-system-custom;
  # Import gvariant for dconf types
  mkTuple = lib.gvariant.mkTuple;
  mkUint32 = lib.gvariant.mkUint32;
  mkEmptyArray = lib.gvariant.mkEmptyArray;
in

{
  options.gnome-system-custom = {
    enableDisplayManager = mkOption {
      type = types.bool;
      default = true;
      description = "Enable GDM display manager";
    };
  };

  config = {
    # GNOME Desktop Environment
    services.xserver.enable = true;
    services.displayManager.gdm.enable = mkIf cfg.enableDisplayManager true;
    services.desktopManager.gnome.enable = true;

    # Keyboard layout
    services.xserver.xkb = {
      layout = "us";
      options = "";
    };

    # Exclude unwanted GNOME default packages
    environment.gnome.excludePackages = with pkgs; [
      gnome-tour
      gnome-console  # terminal (using Ghostty instead)
      gnome-text-editor  # text editor (using Neovim instead)
      gnome-connections  # remote desktop client
      gnome-font-viewer  # font viewer
      seahorse  # passwords and keys
      baobab  # disk usage analyzer
      gnome-disk-utility  # disks
      gnome-logs  # logs viewer
      gnome-system-monitor  # system monitor
      decibels  # audio player
      epiphany  # GNOME web browser
      file-roller  # archive manager
      geary     # GNOME email client
      gnome-music
      gnome-photos
      gnome-maps
      gnome-weather
      gnome-contacts
      gnome-clocks
      gnome-calculator
      gnome-calendar
      gnome-characters
      simple-scan
      snapshot  # camera
      totem     # video player
      yelp      # help viewer
      nautilus  # file manager (using Thunar instead)
    ];

    # XDG portal for proper desktop integration
    xdg.portal = {
      enable = true;
      extraPortals = with pkgs; [
        xdg-desktop-portal-gnome
        xdg-desktop-portal-gtk
      ];
    };

    # Touchpad configuration
    services.libinput = {
      enable = true;
      touchpad = {
        naturalScrolling = true;
        tapping = false;
      };
    };

    # Input method configuration for GNOME
    i18n.inputMethod = {
      enable = true;
      type = "ibus";
      ibus.engines = with pkgs.ibus-engines; [
        libpinyin
      ];
    };

    # GNOME dconf settings
    programs.dconf.profiles.user.databases = [{
      settings = {
        "org/gnome/settings-daemon/plugins/power" = {
          sleep-inactive-ac-type = "nothing";
        };
        "org/gnome/desktop/a11y/applications" = {
          screen-keyboard-enabled = false;
        };
        "org/gnome/desktop/peripherals/mouse" = {
          accel-profile = "flat";
        };
      };
    }];

    # System packages for GNOME
    environment.systemPackages = with pkgs; [
      hicolor-icon-theme  # Fallback icon theme
    ];

  };
}