{ pkgs, ... }:
{
  environment.systemPackages = with pkgs; [
    (python3.withPackages (ps: [ ps.smbus2 ]))
  ];


  # Fan control service
  systemd.services.argon-fan = {
    description = "Argon40 Fan Control via I2C";
    after = [ "multi-user.target" ];
    wantedBy = [ "multi-user.target" ];
    
    serviceConfig = {
      Type = "simple";
      Restart = "always";
      ExecStart = pkgs.writeScript "argon-fan.py" ''
        #!${pkgs.python3.withPackages (ps: [ ps.smbus2 ])}/bin/python3
        import smbus2
        import time
        import subprocess
        
        bus = smbus2.SMBus(1)
        
        while True:
            try:
                # Get temperature
                temp_output = subprocess.check_output(['${pkgs.libraspberrypi}/bin/vcgencmd', 'measure_temp']).decode()
                temp = float(temp_output.replace("temp=","").replace("'C\n",""))
                
                # Set fan speed based on temperature (0-100)
                if temp < 55:
                    speed = 0
                elif temp < 60:
                    speed = 25
                elif temp < 65:
                    speed = 50
                else:
                    speed = 100
                
                bus.write_byte(0x1a, speed)
                print(f"Temp: {temp}°C, Fan: {speed}%")
            except Exception as e:
                print(f"Error: {e}")
            
            time.sleep(30)
      '';
    };
  };
}