{ config, lib, pkgs, ... }:
let
  cfgUser = "dominik"; # Adjust to your username
in {
  #### 1) Provide two scripts:
  ####    - `steam-deck-mode.sh`: Runs Steam Big Picture with Gamescope (Wayland).
  ####    - `sway-session.sh`: Starts Sway.
  environment.etc."steam-deck-mode.sh".text = ''
    #!/usr/bin/env bash

    # This script launches Steam in Big Picture mode under Gamescope (Wayland).
    # Once Steam (or Gamescope) exits, the systemd user service stops.
    # The ExecStopPost hook in the user service will then start Sway automatically.

    # For safety, kill any existing Steam instance
    pgrep steam && steam -shutdown || true
    sleep 1

    # Use Gamescope in fullscreen mode, exit on Steam exit, run Steam in Gamepad UI
    exec gamescope -W 1280 -H 800 -f -e -- steam -gamepadui
  '';

  environment.etc."sway-session.sh".text = ''
    #!/usr/bin/env bash

    # This script starts a Sway session. When Sway exits, the user service stops,
    # which triggers ExecStopPost to start Steam Big Picture again.

    exec sway
  '';

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

  #### 2) Create two systemd *user* services:
  ####    - steam-deck-mode: On stop, automatically start sway
  ####    - sway: On stop, automatically start steam-deck-mode
  systemd.user.services."steam-deck-mode" = {
    description = "Steam Deck Mode (Wayland Gamescope + Steam Big Picture)";
    wantedBy = [ "default.target" ];  # So we can enable it for the user
    serviceConfig = {
      Type = "simple";
      ExecStart = "/etc/steam-deck-mode.sh";
      # On exit, automatically trigger Sway
      ExecStopPost = "${pkgs.systemd}/bin/systemctl --user start sway";
      Restart = "no";  # If Steam crashes, you can change to 'on-failure' if desired
    };
  };

  systemd.user.services."sway" = {
    description = "Sway WM Session";
    wantedBy = [ ];  # We won't start this on login by default, but from steam or a script
    serviceConfig = {
      Type = "simple";
      ExecStart = "/etc/sway-session.sh";
      # On exit, automatically trigger Steam Deck Mode
      ExecStopPost = "${pkgs.systemd}/bin/systemctl --user start steam-deck-mode";
      Restart = "no";
    };
  };

  #### 3) Provide a script & desktop entry to let you switch from Sway to Game Mode easily
  ####    (i.e., stop the 'sway' service, which triggers Steam).
  environment.etc."switch-to-game-mode.sh".text = ''
    #!/usr/bin/env bash
    # This script stops Sway, causing the user service to exit
    # The ExecStopPost of that service will start steam-deck-mode automatically.
    ${pkgs.systemd}/bin/systemctl --user stop sway
  '';

  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 Sway and start Steam Big Picture (Gamescope)
    Exec=/etc/switch-to-game-mode.sh
    Terminal=false
    Type=Application
    Categories=Game;
  '';

  #### 4) If you want to start directly in Steam Deck Mode on boot (no display manager),
  ####    enable auto-login on TTY and run the user service for "dominik".
  ####    For example (uncomment if you want an immediate console login):
  # services.getty.autologinUser = cfgUser;
  # systemd.user.services."steam-deck-mode".wantedBy = [ "default.target" ];  # already set
  # You'd do 'systemctl --user enable steam-deck-mode' as that user to start it on login.

  #### 5) Additional recommended gaming packages if not set elsewhere:
  environment.systemPackages = with pkgs; [
    steam
    gamemode
    mangohud
    vulkan-tools
    vulkan-loader
    vulkan-headers
    # ...
  ];

  #### 6) Enable 32-bit support for Steam
  hardware.opengl.enable = true;
  hardware.opengl.driSupport32Bit = true;
  hardware.graphics.enable = true;
  hardware.graphics.enable32Bit = true;
  hardware.graphics.extraPackages = [
    pkgs.amdvlk
    pkgs.driversi686Linux.amdvlk
  ];

  #### 7) Optionally handle udev rules for Steam/Controllers if needed
  environment.etc."udev/rules.d/99-steamdeck-controller.rules".text = ''
    SUBSYSTEM=="usb", ATTRS{idVendor}=="28de", MODE="0666"
    KERNEL=="uinput", MODE="0660", GROUP="input", OPTIONS+="static_node=uinput"
  '';
}