// Smart Home Automation Code
import 'dart:io';

void main() {
  // Initial device statuses
  bool lightsOn = false;
  double thermostatTemp = 20.0;
  bool securityArmed = false;

  // Constants for temperature range
  const double minTemp = 15.0;
  const double maxTemp = 30.0;

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

  // Main loop for user interaction
  while (true) {
    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('Enter your choice: ');
    String? input = stdin.readLineSync();

    if (input == null) {
      print('Invalid input. Please try again.');
      continue;
    }

    int? choice = int.tryParse(input);

    if (choice == null) {
      print('Invalid input. Please enter a number.');
      continue;
    }

    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();
        if (tempInput == null) {
          print('Invalid input. Please try again.');
          continue;
        }
        double? newTemp = double.tryParse(tempInput);
        if (newTemp == null) {
          print('Invalid temperature. Please enter a number.');
        } else if (newTemp >= minTemp && newTemp <= maxTemp) {
          thermostatTemp = newTemp;
          print('Thermostat set to ${thermostatTemp}°C.');
        } else {
          print('Temperature must be between ${minTemp}°C and ${maxTemp}°C.');
        }
        break;
      case 3:
        securityArmed = !securityArmed;
        print('Security System: ${securityArmed ? "ARMED" : "DISARMED"}.');
        break;
      case 4:
        print('\nSystem Status:');
        print('- Lights: ${lightsOn ? "ON" : "OFF"}');
        String tempStatus = '- Thermostat: ${thermostatTemp}°C';
        if (thermostatTemp % 3 == 0 && thermostatTemp % 5 == 0) {
          tempStatus += ' - Perfect Day';
        } else if (thermostatTemp % 3 == 0) {
          tempStatus += ' - Cool Day';
        } else if (thermostatTemp % 5 == 0) {
          tempStatus += ' - Warm Day';
        }
        print(tempStatus);
        print('- Security System: ${securityArmed ? "ARMED" : "DISARMED"}');
        break;
      case 5:
        print('Exiting the system. Goodbye!');
        return;
      default:
        print('Invalid choice. Please select a valid option.');
    }
  }
}