const int buttonUpPin = 2;
const int buttonDownPin = 3;
const int buttonSelectPin = 4;

int currentMenuItem = 0;
int previousMenuItem = 0;
int totalMenuItem = 4;

bool buttonUpState = false;
bool buttonDownState = false;
bool buttonSelectState = false;
bool menuActive = false;

int x =5;
int y =4;

void setup() {
  // put your setup code here, to run once: 
  pinMode(buttonUpPin, INPUT_PULLUP);
  pinMode(buttonDownPin, INPUT_PULLUP);
  pinMode(buttonSelectPin, INPUT_PULLUP);

  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  buttonUpState = digitalRead(buttonUpPin);
  buttonDownState = digitalRead(buttonDownPin);
  buttonSelectState = digitalRead(buttonSelectPin);

  if (buttonSelectState == LOW) {
    menuActive = true;
    displayMenu();  // Display the menu options in the serial monitor
    while (menuActive) {
      if (buttonUpState == LOW && previousMenuItem != currentMenuItem) {
        currentMenuItem--;
        if (currentMenuItem < 0) {
          currentMenuItem = totalMenuItem - 1;
        }
        displayMenu();
      }
    }
  
  if (buttonDownState == LOW && previousMenuItem != currentMenuItem) {
      currentMenuItem++;
      if (currentMenuItem >= totalMenuItem) {
        currentMenuItem = 0;
      }
      displayMenu();
    }
    previousMenuItem = currentMenuItem;

  if (buttonSelectState == LOW){
    executeSelectedAction();
    menuActive = false;
  }

  buttonUpState = digitalRead(buttonUpPin);
  buttonDownState = digitalRead(buttonDownPin);
  buttonSelectState = digitalRead(buttonSelectPin);
  }
}

void displayMenu() {
  Serial.println("Menu Options:");
  Serial.println("--------------");
  Serial.print("0. Addition");
  if (currentMenuItem == 0) {
    Serial.print(" (selected)");
  }
  Serial.println();
  
  Serial.print("1. Subtraction");
  if (currentMenuItem == 1) {
    Serial.print(" (selected)");
  }
  Serial.println();
  
  Serial.print("2. Multiplication");
  if (currentMenuItem == 2) {
    Serial.print(" (selected)");
  }
  Serial.println();
  
  Serial.println();
  delay(1000);
}

void executeSelectedAction() {
  switch (currentMenuItem) {
    case 0:
      // Addition
      int sum = x + y;
      Serial.print("Result of Addition: ");
      Serial.println(sum);
      break;

    case 1:
      // Subtraction
      int difference = x - y;
      Serial.print("Result of Subtraction: ");
      Serial.println(difference);
      break;

    case 2:
      // Multiplication
      int product = x * y;
      Serial.print("Result of Multiplication: ");
      Serial.println(product);
      break;

    default:
      break;
  }

  Serial.println();  // Add a line break for clarity
}