import 'dart:io';

const int minTemp = 15;
const int maxTemp = 30;

class SmartHome {
  bool lightsOn = false;
  int thermostat = 20;
  bool securityArmed = false;

  void toggleLights() {
    lightsOn = !lightsOn;
    print('Lights are now ${lightsOn ? 'ON' : 'OFF'}');
  }

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

  void toggleSecurity() {
    securityArmed = !securityArmed;
    print('Security system is now ${securityArmed ? 'ARMED' : 'DISARMED'}');
  }

  void showStatus() {
    print('\n--- Smart Home Status ---');
    print('Lights: ${lightsOn ? 'ON' : 'OFF'}');
    print('Thermostat: $thermostat°C');

    // FizzBuzz-like logic
    if (thermostat % 3 == 0 && thermostat % 5 == 0) {
      print('Perfect Day');
    } else if (thermostat % 3 == 0) {
      print('Cool Day');
    } else if (thermostat % 5 == 0) {
      print('Warm Day');
    }

    String securityStatus = securityArmed ? 'ARMED' : 'DISARMED';
    print('Security System: $securityStatus');
  }
}

void main() {
  SmartHome home = SmartHome();
  bool running = true;

  print('🏠 Welcome to Smart Home Automation System');

  while (running) {
    print('\nSelect an option:');
    print('1. Toggle Lights');
    print('2. Set Thermostat Temperature');
    print('3. Toggle Security System');
    print('4. View System Status');
    print('5. Exit');
    stdout.write('Your choice: ');

    String? choice = stdin.readLineSync();

    if (choice == null) continue;

    switch (choice) {
      case '1':
        home.toggleLights();
        break;

      case '2':
        stdout.write('Enter temperature ($minTemp–$maxTemp): ');
        String? input = stdin.readLineSync();
        int? temp = int.tryParse(input ?? '');
        if (temp != null && temp >= minTemp && temp <= maxTemp) {
          home.setTemperature(temp);
        } else {
          print('⚠️ Please enter a valid temperature between $minTemp and $maxTemp.');
        }
        break;

      case '3':
        home.toggleSecurity();
        break;

      case '4':
        home.showStatus();
        break;

      case '5':
        running = false;
        print('👋 Exiting Smart Home System... Goodbye!');
        break;

      default:
        print('❌ Invalid option. Please select between 1–5.');
    }
  }
}