import 'dart:io';

const int minTemperature = 15;
const int maxTemperature = 30;

void main() {
  bool lightsOn = false;
  int temperature = 20;
  bool securityArmed = false;

  bool running = true;

  print("=== Smart Home Automation System ===");

  while (running) {
    print("");
    print("Please choose an option:");
    print("1. Control lights");
    print("2. Set thermostat temperature");
    print("3. Control security system");
    print("4. View system status");
    print("5. Exit");
    stdout.write("Your choice: ");

    String? choice = stdin.readLineSync();

    if (choice == '1') {
      lightsOn = controlLights(lightsOn);
    } else if (choice == '2') {
      temperature = setThermostat(temperature);
    } else if (choice == '3') {
      securityArmed = controlSecurity(securityArmed);
    } else if (choice == '4') {
      displayStatus(lightsOn, temperature, securityArmed);
    } else if (choice == '5') {
      print("Exiting the system. Goodbye!");
      running = false;
    } else {
      print("Invalid choice. Please try again.");
    }
  }
}

bool controlLights(bool currentStatus) {
  print("");
  print("=== Lights Control ===");
  print("1. Turn lights ON");
  print("2. Turn lights OFF");
  stdout.write("Your choice: ");
  String? input = stdin.readLineSync();

  switch (input) {
    case '1':
      print("Lights are now ON.");
      return true;
    case '2':
      print("Lights are now OFF.");
      return false;
    default:
      print("Invalid choice for lights. Status unchanged.");
      return currentStatus;
  }
}

int setThermostat(int currentTemperature) {
  print("");
  print("=== Thermostat Control ===");
  print("Current temperature: $currentTemperature°C");
  stdout.write(
      "Enter new temperature ($minTemperature - $maxTemperature °C): ");

  String? input = stdin.readLineSync();
  int? newTemp = int.tryParse(input ?? "");

  if (newTemp != null &&
      newTemp >= minTemperature &&
      newTemp <= maxTemperature) {
    print("Temperature set to $newTemp°C.");
    return newTemp;
  } else {
    print(
        "Invalid temperature. Please enter a value between $minTemperature and $maxTemperature.");
    print("Temperature remains at $currentTemperature°C.");
    return currentTemperature;
  }
}

bool controlSecurity(bool currentStatus) {
  print("");
  print("=== Security System Control ===");
  print("1. Arm system");
  print("2. Disarm system");
  stdout.write("Your choice: ");
  String? input = stdin.readLineSync();

  switch (input) {
    case '1':
      if (!currentStatus) {
        print("Security system is now ARMED.");
        return true;
      } else {
        print("Security system is already ARMED.");
        return currentStatus;
      }
    case '2':
      if (currentStatus) {
        print("Security system is now DISARMED.");
        return false;
      } else {
        print("Security system is already DISARMED.");
        return currentStatus;
      }
    default:
      print("Invalid choice for security system. Status unchanged.");
      return currentStatus;
  }
}

void displayStatus(bool lightsOn, int temperature, bool securityArmed) {
  print("");
  print("=== System Status ===");

  String lightsStatus = lightsOn ? "ON" : "OFF";
  String securityStatus = securityArmed ? "armed" : "disarmed";
  String securityStatusUpper = securityStatus.toUpperCase();

  String dayMessage = "";
  if (temperature % 3 == 0 && temperature % 5 == 0) {
    dayMessage = "Perfect Day";
  } else if (temperature % 3 == 0) {
    dayMessage = "Cool Day";
  } else if (temperature % 5 == 0) {
    dayMessage = "Warm Day";
  }

  print("Lights: $lightsStatus");
  print("Thermostat: $temperature°C");
  print("Security System: $securityStatusUpper");

  if (dayMessage.isNotEmpty) {
    print("$dayMessage at $temperature°C");
  }
}