Notepad

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 SYSTEM ===');
    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');
    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('Enter temperature ($minTemp–$maxTemp °C): ');
        String? input = stdin.readLineSync();
        if (input != null) {
          int? newTemp = int.tryParse(input);
          if (newTemp != null && newTemp >= minTemp && newTemp <= maxTemp) {
            temperature = newTemp;
            print('Thermostat set to $temperature°C');
          } else {
            print('Invalid input! Temperature must be between $minTemp and $maxTemp.');
          }
        }
        break;

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

      case '4':
        String lightStatus = lightsOn ? "ON" : "OFF";
        String secStatus = securityArmed ? "ARMED" : "DISARMED";
        String dayStatus = '';

        if (temperature % 3 == 0 && temperature % 5 == 0) {
          dayStatus = "Perfect Day";
        } else if (temperature % 3 == 0) {
          dayStatus = "Cool Day";
        } else if (temperature % 5 == 0) {
          dayStatus = "Warm Day";
        }

        print('\n--- SYSTEM STATUS ---');
        print('Lights: $lightStatus');
        print('Thermostat: $temperature°C ${dayStatus.isNotEmpty ? "($dayStatus)" : ""}');
        print('Security System: ${secStatus.toUpperCase()}');
        break;

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

      default:
        print('Invalid choice! Please select 1–5.');
    }
  }
}
