{ config, lib, pkgs, ... }:
let
  cfgUser = "dominik"; # Adjust to your username
in {
  environment.etc."steam-deck-mode.sh".text = ''
    #!/usr/bin/env bash
    # Launches Steam in Big Picture with Gamescope.
    # On exit, user service stops, triggering ExecStopPost to start GNOME.
    pgrep steam && steam -shutdown || true
    sleep 1
    exec gamescope -W 1280 -H 800 -f -e -- steam -gamepadui
  '';

  environment.etc."gnome-session.sh".text = ''
    #!/usr/bin/env bash
    # Start a GNOME session
    exec gnome-session
  '';

  systemd.services."make-scripts-executable" = {
    description = "Make steam-deck-mode and gnome-session scripts executable";
    wantedBy = [ "multi-user.target" ];
    serviceConfig.ExecStart = [
      "${pkgs.coreutils}/bin/chmod +x /etc/steam-deck-mode.sh"
      "${pkgs.coreutils}/bin/chmod +x /etc/gnome-session.sh"
    ];
  };

  # Steam Deck Mode service
  systemd.user.services."steam-deck-mode" = {
    description = "Steam Deck Mode (Gamescope + Steam Big Picture)";
    wantedBy = [ "default.target" ];
    serviceConfig = {
      Type = "simple";
      ExecStart = "/etc/steam-deck-mode.sh";
      ExecStopPost = "${pkgs.systemd}/bin/systemctl --user start gnome-session";
      Restart = "no";
    };
  };

  # GNOME Session (Wayland) service
  systemd.user.services."gnome-session" = {
    description = "GNOME Session (Wayland)";
    wantedBy = [ ];
    serviceConfig = {
      Type = "simple";
      ExecStart = "/etc/gnome-session.sh";
      ExecStopPost = "${pkgs.systemd}/bin/systemctl --user start steam-deck-mode";
      Restart = "no";
    };
  };

  # Quick script to switch from GNOME to Steam Big Picture
  environment.etc."switch-to-game-mode.sh".text = ''
    #!/usr/bin/env bash
    # Stop GNOME => triggers Steam in ExecStopPost
    ${pkgs.systemd}/bin/systemctl --user stop gnome-session
  '';

  systemd.services."make-switch-to-game-mode-executable" = {
    description = "Make switch-to-game-mode.sh executable";
    wantedBy = [ "multi-user.target" ];
    serviceConfig.ExecStart = [
      "${pkgs.coreutils}/bin/chmod +x /etc/switch-to-game-mode.sh"
    ];
  };

  environment.etc."xdg/applications/switch-to-game-mode.desktop".text = ''
    [Desktop Entry]
    Name=Switch to Game Mode
    Comment=Stop GNOME and start Steam (Gamescope)
    Exec=/etc/switch-to-game-mode.sh
    Terminal=false
    Type=Application
    Categories=Game;
  '';

  # Update to new hardware.graphics.* options
  hardware.graphics.enable = true;
  hardware.graphics.enable32Bit = true;

  # Include AMD Vulkan for 64bit & 32bit
  hardware.graphics.extraPackages = [
    pkgs.amdvlk
    pkgs.driversi686Linux.amdvlk
  ];

  # A recommended set of gaming packages
  environment.systemPackages = with pkgs; [
    steam
    gamemode
    mangohud
    vulkan-tools
    vulkan-loader
    vulkan-headers
  ];

  # Move the Steam Deck controller rules to services.udev.extraRules
  # services.udev.extraRules = ''
  #   SUBSYSTEM=="usb", ATTRS{idVendor}=="28de", MODE="0666"
  #   KERNEL=="uinput", MODE="0660", GROUP="input", OPTIONS+="static_node=uinput"
  # '';
}