Smart home

import 'dart:io';

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

void main() {
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');

final choice = _readInt('Enter your choice: ');

// if/else for menu choices (as required)
if (choice == 1) {
lightsOn = !lightsOn;
print('Lights are now ${lightsOn ? "ON" : "OFF"}.');
} else if (choice == 2) {
final temp = _readInt('Set thermostat temperature ($minTemp°C - $maxTemp°C): ');
if (temp < minTemp || temp > maxTemp) {
print('Invalid temperature. Please enter a value between $minTemp and $maxTemp.');
continue; // prompt again
}
thermostat = temp;
print('Thermostat set to ${thermostat}°C.');
} else if (choice == 3) {
// switch for device command (security actions)
print('\nSecurity command:');
print('1. Arm');
print('2. Disarm');
final cmd = _readInt('Enter command: ');

switch (cmd) {
case 1:
if (!securityArmed) {
securityArmed = true;
print('Security system is now ARMED.');
} else {
print('Security system is already ARMED.');
}
break;
case 2:
if (securityArmed) {
securityArmed = false;
print('Security system is now DISARMED.');
} else {
print('Security system is already DISARMED.');
}
break;
default:
print('Invalid command.');
}
} else if (choice == 4) {
final lightsText = lightsOn ? 'ON' : 'OFF';
final securityText = (securityArmed ? 'armed' : 'disarmed').toUpperCase();

final tempLabel = _tempFizzBuzzLabel(thermostat);

print('\nSystem Status:');
print('- Lights: $lightsText');
print('- Thermostat: ${thermostat}°C${tempLabel.isEmpty ? "" : " - $tempLabel"}');
print('- Security System: $securityText');
} else if (choice == 5) {
print('Exiting the system. Goodbye!');
break;
} else {
print('Invalid choice. Please try again.');
}
}
}

String _tempFizzBuzzLabel(int t) {
final is3 = (t % 3 == 0);
final is5 = (t % 5 == 0);

if (is3 && is5) return 'Perfect Day';
if (is3) return 'Cool Day';
if (is5) return 'Warm Day';
return '';
}

int _readInt(String prompt) {
while (true) {
stdout.write(prompt);
final input = stdin.readLineSync();
final value = int.tryParse(input ?? '');
if (value != null) return value;
print('Please enter a valid number.');
}
}