import 'dart:io';

const int MIN_TEMP = 15;
const int MAX_TEMP = 30;

void main() {
  bool lightsOn = false;
  int thermostatTemp = 20;
  bool securityArmed = false;
  
  print("Welcome to the Smart Home System!");
  
  bool exitProgram = false;
  
  while (!exitProgram) {
    print("Please 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();
    
    if (choice != null) {
      if (choice == '1') {
        lightsOn = !lightsOn;
        print("Lights are now ${lightsOn ? 'ON' : 'OFF'}.\n");
        
      } else if (choice == '2') {
	bool validTemp = false;
         while (!validTemp) {
        stdout.write("Set thermostat temperature ($MIN_TEMP°C - $MAX_TEMP°C): ");
        String? tempInput = stdin.readLineSync();
        
        if (tempInput != null) {
          int? temp = int.tryParse(tempInput);
	    if (temp != null && temp >= MIN_TEMP && temp <= MAX_TEMP) {
         
            thermostatTemp = temp;
            print("Thermostat set to $thermostatTemp°C\n");
            break;
          } else {
            print("Invalid temperature! Please enter a value between $MIN_TEMP and $MAX_TEMP.");
          }
        }
         }
      } else if (choice == '3') {
            securityArmed = !securityArmed;
            print("Security Armed Status is now ${securityArmed ? 'ON' : 'OFF'}.\n");

      } else if (choice == '4') {
        print("\nSystem Status:");
        print("- Lights: $lightsOn");
        print("- Thermostat: $thermostatTemp °C ");
        print("- Security System: $securityArmed\n");
      } else if (choice == '5') {
        exitProgram = true;
        print("Exiting the system. Goodbye!");
      } else {
        print("Invalid choice! Please select 1-5.");
      }
    }
  }
}