NixOS-Config/modules/system/devices/video/nvidia/default.nix

{ lib, pkgs, config, ... }:
{
  options.system.video = {
    nvidia = {                     
      enable = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = "Enable the proprietary Nvidia stack";
      };                                                                 
    };                                                                   
    nouveau = {                                                          
      enable = lib.mkOption {                                     
        type = lib.types.bool;
        default = false;
        description = "Enable the open-source Nouveau driver";
      };                
    };
  };

  config = {
    # Conditionally set video drivers based on the options
    services.xserver.videoDrivers = 
      if config.system.video.nvidia.enable then [ "nvidia" ]
      else if config.system.video.nouveau.enable then [ "nouveau" ]
      else [];

    # Configure Nvidia settings if Nvidia is enabled
    hardware = {
      nvidia = lib.mkIf config.system.video.nvidia.enable {
        modesetting.enable = true;
        nvidiaSettings = false;
        package = config.boot.kernelPackages.nvidiaPackages.beta;
        open = false;
      };
      opengl.extraPackages = with pkgs; [ nvidia-vaapi-driver ];
    };
  };
}