import 'dart:io';

void main() {
  bool lightsOn = false;
  int thermostat = 20;
  bool securityArmed = false;

  const int minTemp = 15;
  const int maxTemp = 30;

  while (true) {
    print('\n--- Smart Home Control ---');
    print('1. Toggle Lights');
    print('2. Set Thermostat');
    print('3. Arm/Disarm Security System');
    print('4. View System Status');
    print('5. Exit');

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

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

      case '2':
        stdout.write('Enter temperature ($minTemp-$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');
        } else {
          print('Invalid temperature! Please enter a value between $minTemp and $maxTemp.');
        }
        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";

        print('\n--- System Status ---');
        print('Lights: $lightsStatus');
        print('Thermostat: $thermostat°C');
        print('Security: $securityStatus');

        if (thermostat % 3 == 0 && thermostat % 5 == 0) {
          print('Perfect Day!');
        } else if (thermostat % 3 == 0) {
          print('Cool Day!');
        } else if (thermostat % 5 == 0) {
          print('Warm Day!');
        }
        break;

      case '5':
        print('Exiting... Goodbye!');
        return;

      default:
        print('Invalid choice! Please try again.'