import 'dart:io';

void main() {
  const int minTemp = 15;
  const int maxTemp = 30;
  bool lightsOn = false;
  int temperature = 20;
  bool securityArmed = false;

  while (true) {
    print('\n=== Smart Home Automation ===');
    print('1. Toggle Lights');
    print('2. Set Thermostat');
    print('3. Arm/Disarm Security');
    print('4. View Status');
    print('5. Exit');
    stdout.write('Enter your choice: ');
    String? choice = stdin.readLineSync();

    switch (choice) {
      case '1':
        lightsOn = !lightsOn;
        print('Lights are now ${lightsOn ? "ON" : "OFF"}');
        break;

      case '2':
        stdout.write('Enter temperature ($minTemp - $maxTemp): ');
        int? temp = int.tryParse(stdin.readLineSync() ?? '');
        if (temp != null && temp >= minTemp && temp <= maxTemp) {
          temperature = temp;
        } else {
          print('Invalid temperature value!');
        }
        break;

      case '3':
        securityArmed = !securityArmed;
        print('Security system is now ${securityArmed ? "ARMED" : "DISARMED"}');
        break;

      case '4':
        String status = '''
Lights: ${lightsOn ? "ON" : "OFF"}
Thermostat: $temperature°C
Security: ${securityArmed ? "ARMED" : "DISARMED"}
''';
        if (temperature % 3 == 0 && temperature % 5 == 0) {
          status += "Perfect Day\n";
        } else if (temperature % 3 == 0) {
          status += "Cool Day\n";
        } else if (temperature % 5 == 0) {
          status += "Warm Day\n";
        }
        print(status);
        break;

      case '5':
        print('Exiting system...');
        return;

      default:
        print('Invalid choice!');
    }
  }
}