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

let
  cfg = config.programs.river;

  wayland-lib = import ./lib.nix { inherit lib; };
in
{
  options.programs.river = {
    enable = lib.mkEnableOption "river, a dynamic tiling Wayland compositor";

    package = lib.mkPackageOption pkgs "river" {
      nullable = true;
      extraDescription = ''
        If the package is not overridable with `xwaylandSupport`, then the module option
        {option}`xwayland` will have no effect.

        Set to `null` to not add any River package to your path.
        This should be done if you want to use the Home Manager River module to install River.
      '';
    } // {
      apply = p: if p == null then null else
        wayland-lib.genFinalPackage p {
          xwaylandSupport = cfg.xwayland.enable;
        };
    };

    xwayland.enable = lib.mkEnableOption "XWayland" // { default = true; };

    extraPackages = lib.mkOption {
      type = with lib.types; listOf package;
      default = with pkgs; [ swaylock foot dmenu ];
      defaultText = lib.literalExpression ''
        with pkgs; [ swaylock foot dmenu ];
      '';
      example = lib.literalExpression ''
        with pkgs; [ termite rofi light ]
      '';
      description = ''
        Extra packages to be installed system wide. See
        [Common X11 apps used on i3 with Wayland alternatives](https://github.com/swaywm/sway/wiki/i3-Migration-Guide#common-x11-apps-used-on-i3-with-wayland-alternatives)
        for a list of useful software.
      '';
    };
  };

  config = lib.mkIf cfg.enable (lib.mkMerge [
    {
      environment.systemPackages = lib.optional (cfg.package != null) cfg.package ++ cfg.extraPackages;

      # To make a river session available if a display manager like SDDM is enabled:
      services.displayManager.sessionPackages = lib.optional (cfg.package != null) cfg.package;

      # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1050913
      xdg.portal.config.river.default = lib.mkDefault [ "wlr" "gtk" ];
    }

    (import ./wayland-session.nix {
      inherit lib pkgs;
      enableXWayland = cfg.xwayland.enable;
    })
  ]);

  meta.maintainers = with lib.maintainers; [ GaetanLepage ];
}
