import 'dart:io';

void main() {
  const int minTemp = 15;
  const int maxTemp = 30;
  
  bool lightsOn = false;
  int thermostatTemp = 20;
  bool securityArmed = false;
  
  print('Welcome to the Smart Home System!');
  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\n');
  
  bool running = true;
  
  while (running) {
    stdout.write('Enter your choice: ');
    String? input = stdin.readLineSync();
    
    if (input == null || input.isEmpty) {
      print('Invalid input.\n');
      continue;
    }
    
    int? choice = int.tryParse(input);
    
    if (choice == null) {
      print('Invalid input.\n');
      continue;
    }
    
    switch (choice) {
      case 1:
        if (lightsOn == true) {
          lightsOn = false;
          print('Lights are now OFF.\n');
        } else {
          lightsOn = true;
          print('Lights are now ON.\n');
        }
        break;
        
      case 2:
        print('Set thermostat temperature ($minTemp°C - $maxTemp°C): ');
        String? tempInput = stdin.readLineSync();
        
        if (tempInput != null && tempInput.isNotEmpty) {
          int? temp = int.tryParse(tempInput);
          
          if (temp != null && temp >= minTemp && temp <= maxTemp) {
            thermostatTemp = temp;
            print('Thermostat set to $thermostatTemp°C.\n');
          } else {
            print('Invalid temperature. Please enter a value between $minTemp°C and $maxTemp°C.\n');
          }
        } else {
          print('Invalid input.\n');
        }
        break;
        
      case 3:
        if (securityArmed == true) {
          securityArmed = false;
          print('Security system is now DISARMED.\n');
        } else {
          securityArmed = true;
          print('Security system is now ARMED.\n');
        }
        break;
        
      case 4:
        print('System Status:');
        
        if (lightsOn == true) {
          print('- Lights: ON');
        } else {
          print('- Lights: OFF');
        }
        
        if (thermostatTemp % 3 == 0 && thermostatTemp % 5 == 0) {
          print('- Thermostat: $thermostatTemp°C - Perfect Day');
        } else if (thermostatTemp % 3 == 0) {
          print('- Thermostat: $thermostatTemp°C - Cool Day');
        } else if (thermostatTemp % 5 == 0) {
          print('- Thermostat: $thermostatTemp°C - Warm Day');
        } else {
          print('- Thermostat: $thermostatTemp°C');
        }
        
        if (securityArmed == true) {
          String status = 'armed';
          print('- Security System: ${status.toUpperCase()}\n');
        } else {
          String status = 'disarmed';
          print('- Security System: ${status.toUpperCase()}\n');
        }
        break;
        
      case 5:
        print('Exiting the system. Goodbye!');
        running = false;
        break;
        
      default:
        print('Invalid choice.\n');
        break;
    }
  }
}