import 'dart:io';

// Constant temperature limits
const int minTemp = 15;
const int maxTemp = 30;

void main() {
  // Initial device states
  bool lightsOn = false;
  int thermostat = 20;
  bool securityArmed = false;

  print("=== SMART HOME AUTOMATION SYSTEM ===");

  while (true) {
    print("\nChoose an option:");
    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();

    if (choice == null) continue;

    if (choice == "5") {
      print("Exiting Smart Home System. Goodbye!");
      break;
    }

    switch (choice) {
      case "1":
        lightsOn = !lightsOn;
        print("Lights have been turned ${lightsOn ? 'ON' : 'OFF'}.");
        break;

      case "2":
        stdout.write("Enter temperature ($minTemp - $maxTemp): ");
        String? tempInput = stdin.readLineSync();

        if (tempInput == null) break;

        int? newTemp = int.tryParse(tempInput);

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

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

      case "4":
        print("\n--- SYSTEM STATUS ---");

        // Lights status
        String lightStatus = lightsOn ? "ON" : "OFF";

        // Security status (uppercase)
        String securityStatus = securityArmed ? "ARMED" : "DISARMED";

        // FizzBuzz-like temperature message
        String tempMessage = "";
        bool mult3 = thermostat % 3 == 0;
        bool mult5 = thermostat % 5 == 0;

        if (mult3 && mult5) {
          tempMessage = "Perfect Day";
        } else if (mult3) {
          tempMessage = "Cool Day";
        } else if (mult5) {
          tempMessage = "Warm Day";
        }

        print("Lights: $lightStatus");
        print("Thermostat: $thermostat°C ${tempMessage.isNotEmpty ? '($tempMessage)' : ''}");
        print("Security System: ${securityStatus.toUpperCase()}");
        break;

      default:
        print("Invalid choice. Please select a valid option.");
    }
  }
}