import 'dart:io';

void main() {
  // Default device states
  bool lightsOn = false;
  int thermostatTemp = 20;
  bool securityArmed = false;

  print('Welcome to the Smart Home System!');

  while (true) {
    print('\nPlease choose an action:');
    print('1. Toggle lights');
    print('2. Set thermostat temperature');
    print('3. Arm/disarm security system');
    print('4. View system status');
    print('5. Exit');

    stdout.write('Enter your choice: ');
    String? choice = stdin.readLineSync();

    if (choice == null) continue;

    switch (choice) {
      case '1':
        lightsOn = !lightsOn;
        print('Lights are now ${lightsOn ? "ON" : "OFF"}.');
        break;
      case '2':
        stdout.write('Set thermostat temperature (15°C - 30°C): ');
        String? tempInput = stdin.readLineSync();
        if (tempInput == null) break;
        int? newTemp = int.tryParse(tempInput);
        if (newTemp == null) {
          print('Invalid input. Please enter a number.');
          break;
        }
        if (newTemp >= 15 && newTemp <= 30) {
          thermostatTemp = newTemp;
          print('Thermostat set to $thermostatTemp°C.');
        } else {
          print('Temperature must be between 15°C and 30°C.');
        }
        break;
      case '3':
        securityArmed = !securityArmed;
        print('Security system is now ${securityArmed ? "ARMED" : "DISARMED"}.');
        break;
      case '4':
        String lightsStatus = lightsOn ? "ON" : "OFF";
        String securityStatus = securityArmed ? "ARMED" : "DISARMED";
        String dayType = '';
        if (thermostatTemp % 3 == 0 && thermostatTemp % 5 == 0) {
          dayType = 'Perfect Day';
        } else if (thermostatTemp % 3 == 0) {
          dayType = 'Cool Day';
        } else if (thermostatTemp % 5 == 0) {
          dayType = 'Warm Day';
        }
        print('\nSystem Status:');
        print('Lights: $lightsStatus');
        print('Thermostat: $thermostatTemp°C${dayType.isNotEmpty ? " ($dayType)" : ""}');
        print('Security System: $securityStatus');
        break;
      case '5':
        print('Exiting the system. Goodbye!');
        return;
      default:
        print('Invalid choice. Please select a number between 1 and 5.');
    }
  }
}