import 'dart:io';

void main() {
  // Const Variables for Temperature Range
  const int minTemp = 15;
  const int maxTemp = 30;

  // Device Status
  bool lightsOn = false;
  int thermostatTemp = 20;
  bool isArmed = false;

  print('Welcome to the Smart Home System!');

  // User Interaction
  bool running = true;
  while (running) {
    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('\nEnter your choice: ');
    String? choice = stdin.readLineSync();

    // Control Flow
    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? tempInput = stdin.readLineSync();
        int? newTemp = int.tryParse(tempInput ?? '');

        // Input Validation & Logical Operators
        if (newTemp != null && newTemp >= minTemp && newTemp <= maxTemp) {
          thermostatTemp = newTemp;
          print('Thermostat set to $thermostatTemp°C.');
        } else {
          print('Invalid input. Please enter a value between $minTemp and $maxTemp.');
        }
        break;
        case '3':
        isArmed = !isArmed;

        // String Operation: Converting status to Uppercase
        String armStatus = isArmed ? 'armed' : 'disarmed';
        print('Security System is now ${armStatus.toUpperCase()}.');
        break;

        case '4':
        // Logic for temperature adjectives
        String tempCondition = '';
        if (thermostatTemp % 3 == 0 && thermostatTemp % 5 == 0) {
          tempCondition = '– Perfect Day';
        } else if (thermostatTemp % 3 == 0) {
          tempCondition = '– Cool Day';
        } else if (thermostatTemp % 5 == 0) {
          tempCondition = '– Warm Day';
        }

        // status display
        print('System Status:');
        print('- Lights: ${lightsOn ? "ON" : "OFF"}');
        print('- Thermostat: $thermostatTemp°C $tempCondition');
        print('- Security System: ${(isArmed ? "armed" : "disarmed").toUpperCase()}');
        break;

      case '5':
        print('Exiting the system. Goodbye!');
        running = false;
        break;

      default:
        print('Invalid choice. Please select 1-5.');
    }
  }
}