import 'dart:io';

void main() {
  const int minTemp = 15;
  const int maxTemp = 30;

  bool lightsOn = false;
  int thermostat = 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? choiceInput = stdin.readLineSync();
    if (choiceInput == null || choiceInput.isEmpty) {
      print('No input detected. Try again.');
      continue;
    }

    int? choice = int.tryParse(choiceInput);
    if (choice == null) {
      print('Invalid input. Enter a number between 1 and 5.');
      continue;
    }

    switch (choice) {
      case 1:
        lightsOn = !lightsOn;
        print('Lights are now ${lightsOn ? "ON" : "OFF"}.');
        break;
      case 2:
        while (true) {
          stdout.write('Set thermostat temperature ($minTemp°C – $maxTemp°C): ');
          String? tempInput = stdin.readLineSync();
          int? temp = int.tryParse(tempInput ?? '');
          if (temp != null && temp >= minTemp && temp <= maxTemp) {
            thermostat = temp;
            print('Thermostat set to $thermostat°C.');
            break;
          } else {
            print('Invalid temperature. Enter a value between $minTemp and $maxTemp.');
          }
        }
        break;
      case 3:
        securityArmed = !securityArmed;
        print('Security System is now ${securityArmed ? "ARMED" : "DISARMED"}.');
        break;
      case 4:
        print('System Status:');
        print('- Lights: ${lightsOn ? "ON" : "OFF"}');
        String dayMessage = '';
        if (thermostat % 3 == 0 && thermostat % 5 == 0) {
          dayMessage = ' – Perfect Day';
        } else if (thermostat % 3 == 0) {
          dayMessage = ' – Cool Day';
        } else if (thermostat % 5 == 0) {
          dayMessage = ' – Warm Day';
        }
        print('- Thermostat: $thermostat°C$dayMessage');
        print('- Security System: ${securityArmed ? "ARMED" : "DISARMED"}');
        break;
      case 5:
        print('Exiting the system. Goodbye!');
        return;
      default:
        print('Invalid choice. Enter a number between 1 and 5.');
    }
  }
}