import 'dart:io';

// Define constants
const int MIN_TEMP = 15;
const int MAX_TEMP = 30;

// Define device status
Map<String, dynamic> deviceStatus = {
  'lightsOn': false,
  'thermostatTemp': 20, // Default value 20°C
  'securityArmed': false, // Default value DISARMED
};

// Main function to run the system
void main() {
  print('Welcome to the Smart Home System!');
  
  // Loop for continuous user interaction
  while (true) {
    displayMenu();
    
    // Read user choice
    String? choiceInput = stdin.readLineSync();
    int? choice = int.tryParse(choiceInput ?? '');

    if (choice == null) {
      print('Invalid input. Please enter a number from 1 to 5.');
      continue;
    }

    switch (choice) {
      case 1:
        toggleLights();
        break;
      case 2:
        setThermostatTemperature();
        break;
      case 3:
        armDisarmSecurity();
        break;
      case 4:
        viewSystemStatus();
        break;
      case 5:
        print('Exiting the system. Goodbye!');
        return; // Exit the main function and the program
      default:
        print('Invalid choice. Please select an option from 1 to 5.');
    }
    print(''); // Newline for separation
  }
}

// Display menu options
void displayMenu() {
  print('Please choose an action:');
  print('1. Toggle lights');
  print('2. Set thermostat temperature (${MIN_TEMP}°C - ${MAX_TEMP}°C)');
  print('3. Arm/disarm security system');
  print('4. View system status');
  print('5. Exit');
  stdout.write('Enter your choice: ');
}

// 1. Toggle lights
void toggleLights() {
  deviceStatus['lightsOn'] = !deviceStatus['lightsOn'];
  String status = deviceStatus['lightsOn'] ? 'ON' : 'OFF';
  print('Lights are now $status.');
}

// 2. Set thermostat temperature
void setThermostatTemperature() {
  stdout.write('Enter thermostat temperature (${MIN_TEMP}°C - ${MAX_TEMP}°C): ');
  String? tempInput = stdin.readLineSync();
  int? newTemp = int.tryParse(tempInput ?? '');

  // Input validation
  if (newTemp == null || newTemp < MIN_TEMP || newTemp > MAX_TEMP) {
    print('Invalid temperature. Please enter a number between $MIN_TEMP and $MAX_TEMP.');
    return;
  }

  deviceStatus['thermostatTemp'] = newTemp;
  print('Thermostat set to ${newTemp}°C.');
}

// 3. Arm/disarm security system
void armDisarmSecurity() {
  deviceStatus['securityArmed'] = !deviceStatus['securityArmed'];
  String status = deviceStatus['securityArmed'] ? 'ARMED' : 'DISARMED';
  print('Security system is now $status.');
}

// 4. View system status
void viewSystemStatus() {
  String lightsStatus = deviceStatus['lightsOn'] ? 'ON' : 'OFF';
  String securityStatus = deviceStatus['securityArmed'] ? 'ARMED' : 'DISARMED';
  int currentTemp = deviceStatus['thermostatTemp'];
  
  // FizzBuzz-like exercise to determine day status
  String dayStatus;
  if (currentTemp % 3 == 0 && currentTemp % 5 == 0) {
    dayStatus = 'Perfect Day';
  } else if (currentTemp % 3 == 0) {
    dayStatus = 'Cool Day';
  } else if (currentTemp % 5 == 0) {
    dayStatus = 'Warm Day';
  } else {
    dayStatus = 'Normal Day';
  }

  // Use String Interpolation to display status
  print('''
System Status:
- Lights: $lightsStatus
- Thermostat: ${currentTemp}°C - $dayStatus
- Security System: $securityStatus
''');
}