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");

    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°C - $maxTemp°C): ");
        String? input = stdin.readLineSync();
        int? temp = int.tryParse(input ?? "");

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

      case "3":
        securityArmed = !securityArmed;
        String statusMsg = securityArmed ? "armed" : "disarmed";
        print("Security system is now ${statusMsg.toUpperCase()}.");
        break;

      case "4":
        String lightsStatus = lightsOn ? "on" : "off";
        String securityStatus = securityArmed ? "armed" : "disarmed";

        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: ${lightsStatus.toUpperCase()}");
        print("- Thermostat: $thermostat°C${dayStatus.isNotEmpty ? " - $dayStatus" : ""}");
        print("- Security System: ${securityStatus.toUpperCase()}");
        break;

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

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