{ config, pkgs, ... }:

{
  imports =
    [ # Include X settings.
      ../.
    ];

  # Enable Gnome and GDM.
  services.xserver.displayManager.gdm.enable = true;
  services.xserver.desktopManager.gnome.enable = true;

  security.pam.services.gdm.enableKwallet = true;

  services.udev.packages = with pkgs; [ gnome.gnome-settings-daemon ];

  environment.systemPackages = with pkgs; [
    gnome.gnome-software
    gnomeExtensions.appindicator
    gnomeExtensions.blur-my-shell
    gnomeExtensions.gsconnect
    gnomeExtensions.night-theme-switcher
    gnomeExtensions.noannoyance-fork
    gnomeExtensions.tailscale-status
    gnomeExtensions.tiling-assistant
    # pkgs.libsForQt5.kwalletmanager
  ];

  # Prefer baset set of gnome apps from Flatpaks.
  environment.gnome.excludePackages = (with pkgs; [
    baobab
    epiphany
    evince
    gnome-connections
    gnome-photos
    gnome-text-editor
    gnome-tour
    loupe
    snapshot # webcam tool
  ]) ++ (with pkgs.gnome; [
    geary # email reader
    gnome-calculator
    gnome-calendar
    gnome-characters
    gnome-clocks
    gnome-contacts
    gnome-logs
    gnome-music
    gnome-weather
    sushi
    totem # video player
  ]);

  services.flatpak.packages = [
    "com.github.tchx84.Flatseal"
    "org.gnome.baobab"
    "org.gnome.Builder"
    "org.gnome.Calculator"
    "org.gnome.Characters"
    "org.gnome.clocks"
    "org.gnome.Connections"
    "org.gnome.Contacts"
    "org.gnome.Epiphany"
    "org.gnome.Evince"
    "org.gnome.Fractal"
    "org.gnome.Geary"
    "org.gnome.Logs"
    "org.gnome.Loupe"
    "org.gnome.Music"
    "org.gnome.NautilusPreviewer"
    "org.gnome.Photos"
    "org.gnome.Snapshot"
    "org.gnome.TextEditor"
    "org.gnome.Totem"
    "org.gnome.Weather"
    "org.gnome.Calendar"
  ];

  nixpkgs.overlays = [
    (final: prev: {
      gnome = prev.gnome.overrideScope (gnomeFinal: gnomePrev: {
        mutter = gnomePrev.mutter.overrideAttrs ( old: {
          src = pkgs.fetchgit {
            url = "https://gitlab.gnome.org/vanvugt/mutter.git";
            # GNOME 45: triple-buffering-v4-45
            rev = "0b896518b2028d9c4d6ea44806d093fd33793689";
            sha256 = "sha256-mzNy5GPlB2qkI2KEAErJQzO//uo8yO0kPQUwvGDwR4w=";
          };
        } );
      });
    })
  ];
}