import 'dart:io';

void main() {
  // Initialize the system with default values
  bool lightsOn = false;
  int thermostat = 20;
  bool securityArmed = false;

  while (true) {
    // Display options menu to the user
    print('\nChoose an action:');
    print('1. Turn lights on/off');
    print('2. Set thermostat temperature');
    print('3. Arm/disarm security system');
    print('4. View system status');
    print('5. Exit');

    String? choice = stdin.readLineSync();

    switch (choice) {
      case '1':
        lightsOn = !lightsOn;
        print(lightsOn ? 'Lights are now ON' : 'Lights are now OFF');
        break;
      case '2':
        print('Enter a temperature between 15 and 30:');
        int? temp = int.tryParse(stdin.readLineSync() ?? '');
        if (temp != null && temp >= 15 && temp <= 30) {
          thermostat = temp;
          print('Thermostat set to $thermostat °C.');
        } else {
          print('Invalid temperature.');
        }
        break;
      case '3':
        securityArmed = !securityArmed;
        print(securityArmed ? 'Security system is ARMED' : 'Security system is DISARMED');
        break;
      case '4':
        print('System Status:');
        print('Lights: ${lightsOn ? "ON" : "OFF"}');
        print('Thermostat: $thermostat °C (${thermostat % 3 == 0 ? "Cool Day" : thermostat % 5 == 0 ? "Warm Day" : "Moderate Day"})');
        print('Security System: ${securityArmed ? "ARMED" : "DISARMED"}');
        break;
      case '5':
        print('Goodbye!');
        return;
      default:
        print('Invalid choice.');
    }
  }
}