// Import dart:io to allow console input and output
import 'dart:io';

void main() {
  // Define constant values for the minimum and maximum thermostat temperature
  const int minTemp = 15;
  const int maxTemp = 30;

  // Initialize device statuses
  bool lightsOn = false;        // Lights are initially OFF
  int thermostat = 20;          // Thermostat default temperature is 20°C
  bool securityArmed = false;   // Security system is initially DISARMED

  // Display a welcome message
  print("Welcome to Smart Home Automation System!");

  // Start an infinite loop to continuously show the menu until the user exits
  while (true) {
    // Display the menu options
    print("\n========= MENU =========");
    print("1. Turn Lights On/Off");
    print("2. Set Thermostat Temperature");
    print("3. Arm/Disarm Security System");
    print("4. View System Status");
    print("5. Exit");

    // Prompt user to enter their choice
    stdout.write("Enter your choice (1-5): ");
    String? choice = stdin.readLineSync(); // Read user input from console

    // If input is null, skip this iteration and ask again
    if (choice == null) continue;

    // Handle the user's choice using a switch statement
    switch (choice) {

      // Option 1: Toggle lights on/off
      case '1':
        lightsOn = !lightsOn; // Change lights state
        print(lightsOn ? "Lights turned ON." : "Lights turned OFF.");
        break;

      // Option 2: Set thermostat temperature
      case '2':
        stdout.write("Enter temperature ($minTemp-$maxTemp): ");
        String? tempInput = stdin.readLineSync(); // Read temperature input
        if (tempInput != null) {
          int? temp = int.tryParse(tempInput); // Convert input to integer
          // Validate temperature range
          if (temp != null && temp >= minTemp && temp <= maxTemp) {
            thermostat = temp;
            print("Thermostat set to $thermostat°C");
          } else {
            print("Invalid temperature! Must be between $minTemp and $maxTemp.");
          }
        }
        break;

      // Option 3: Toggle security system armed/disarmed
      case '3':
        securityArmed = !securityArmed; // Change security system state
        print(securityArmed ? "Security System ARMED." : "Security System DISARMED.");
        break;

      // Option 4: View the current system status
      case '4':
        // Convert boolean states to readable text
        String lightsStatus = lightsOn ? "ON" : "OFF";
        String securityStatus = securityArmed ? "ARMED" : "DISARMED";

        // FizzBuzz-like logic based on thermostat temperature
        if (thermostat % 3 == 0 && thermostat % 5 == 0) {
          print("Perfect Day - Temperature: $thermostat°C");
        } else if (thermostat % 3 == 0) {
          print("Cool Day - Temperature: $thermostat°C");
        } else if (thermostat % 5 == 0) {
          print("Warm Day - Temperature: $thermostat°C");
        } else {
          print("Temperature: $thermostat°C");
        }

        // Display lights and security system statuses
        print("Lights: $lightsStatus");
        print("Security System: $securityStatus");
        break;

      // Option 5: Exit the program
      case '5':
        print("Exiting Smart Home System. Goodbye!");
        return; // Stop program execution

      // Handle invalid menu options
      default:
        print("Invalid choice! Please select between 1 and 5.");
    }
  }
}