import 'dart:io';

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

  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");

    stdout.write("Enter 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℃ - $maxTemp℃): ");
        int? temp = int.tryParse(stdin.readLineSync() ?? "");
        if (temp != null && temp >= minTemp && temp <= maxTemp) {
          thermostat = temp;
          print("Thermostat set to $thermostat℃.");
        } else {
          print("Invalid temperature! Please enter between $minTemp and $maxTemp.");
        }
        break;

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

      case '4':
        String dayStatus = "";
        if (thermostat % 3 == 0 && thermostat % 5 == 0) {
          dayStatus = "Perfect Day";
        } else if (thermostat % 3 == 0) {
          dayStatus = "Cool Day";
        } else if (thermostat % 5 == 0) {
          dayStatus = "Warm Day";
        }

        print("\nSystem Status:");
        print("- Lights: ${lightsOn ? 'ON' : 'OFF'}");
        print("- Thermostat: $thermostat℃ ${dayStatus.isNotEmpty ? '- $dayStatus' : ''}");
        print("- Security System: ${securityArmed ? 'ARMED' : 'DISARMED'}");
        break;

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

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