import 'dart:io'; void main() { const int minTemp = 15; const int maxTemp = 30; bool lightsOn = false; int thermostat = 20; bool securityArmed = false; while (true) { print('\nWelcome to the Smart Home System!'); print('Please 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('\nEnter your choice: '); String? choice = stdin.readLineSync(); switch (choice) { case '1': lightsOn = !lightsOn; print('Lights are now ${lightsOn ? "ON" : "OFF"}.'); break; case '2': stdout.write( 'Set thermostat temperature ($minTemp°C - $maxTemp°C): '); String? input = stdin.readLineSync(); int? temp = int.tryParse(input ?? ''); if (temp == null || temp < minTemp || temp > maxTemp) { print('Invalid temperature! Please enter a value between $minTemp and $maxTemp.'); } else { thermostat = temp; print('Thermostat set to $thermostat°C.'); } break; case '3': securityArmed = !securityArmed; print('Security system is now ${securityArmed ? "ARMED" : "DISARMED"}.'); break; case '4': print('\nSystem Status:'); print('- Lights: ${lightsOn ? "ON" : "OFF"}'); print('- Thermostat: $thermostat°C – ${getDayType(thermostat)}'); print('- Security System: ${securityArmed ? "ARMED" : "DISARMED"}'); break; case '5': print('Exiting the system. Goodbye!'); return; default: print('Invalid choice! Please try again.'); } } } String getDayType(int temp) { if (temp % 3 == 0 && temp % 5 == 0) { return 'Perfect Day'; } else if (temp % 3 == 0) { return 'Cool Day'; } else if (temp % 5 == 0) { return 'Warm Day'; } else { return 'Normal Day'; } }