import 'dart:io';

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

// System states
bool lightsOn = false;
bool securityArmed = false;
int thermostat = 20;

int choice = 0;

print("Welcome to the Smart Home System!");

while (choice != 5) {
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: ");
choice = int.parse(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): ");
int temp = int.parse(stdin.readLineSync()!);

if (temp >= minTemp && temp <= maxTemp) {
thermostat = temp;
print("Thermostat set to $thermostat°C.");
} else {
print("Invalid temperature! Must be between $minTemp and $maxTemp.");
}
break;

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

case 4:
print("\nSystem Status:");
print("- Lights: ${lightsOn ? "ON" : "OFF"}");

String weather;
if (thermostat >= 25) {
weather = "Warm Day";
} else if (thermostat <= 18) {
weather = "Cold Day";
} else {
weather = "Moderate";
}

print("- Thermostat: $thermostat°C - $weather");
print("- Security System: ${securityArmed ? "ARMED" : "DISARMED"}");
break;

case 5:
print("Exiting the system. Goodbye!");
break;

default:
print("Invalid choice. Try again.");
}
}
}