#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int buttonPin2 = 3;
const int buttonPin3 = 4; // Add button 3
const int buttonPin4 = 5; // Add button 4
int selectedProduct = 0;
bool isButtonPressed = false;
int led = 11;

String productNames[] = {"Fried", "Pizza", "Pasta", "Salad", "Drink"};
float productPrices[] = {6, 8, 7, 4, 1};
int menu = 0; // 0 for product details, 1 for shopping cart
String cartProducts[5];
float cartPrices[5];
int cartItemCount = 0;
int currentCartItem = -1; // Giữ thông tin đồ ăn hiện tại
int currentCartItemIndex = 0;
void setup() {
  lcd.init();
  lcd.backlight();
  pinMode(led, OUTPUT);
  pinMode(buttonPin2, INPUT_PULLUP);
  pinMode(buttonPin3, INPUT_PULLUP); // Initialize button 3
  pinMode(buttonPin4, INPUT_PULLUP); // Initialize button 4
}

void loop() {
  if (digitalRead(buttonPin2) == LOW) {
    menu = (menu + 1) % 3; // Switch between 0 and 1
      delay(200); // Debouncing delay
  }
  

  if (menu == 0) {
    displayWelcomeScreen();
  } else if (menu == 1) {
    handleButton3Press();

  } else if (menu == 2) {
    // Shopping cart menu
    // Add logic for shopping cart menu
     displayShoppingCart();
  }
}

void displayWelcomeScreen() {
  lcd.setCursor(2, 0);
  lcd.print("Welcome to ");
  lcd.setCursor(0, 1);
  lcd.print("FastFood Chill");

}

void handleButton3Press() {
  lcd.clear();
  while (digitalRead(buttonPin2) == HIGH) {
    if (digitalRead(buttonPin3) == HIGH) {
      // Increment the selected product index
      selectedProduct = (selectedProduct + 1) % 5;

      // Display the details of the newly selected food item
      lcd.setCursor(0, 0);
      lcd.print("Food: ");
      lcd.print(productNames[selectedProduct]);
      lcd.setCursor(0, 1);
      lcd.print("Price: $");
      lcd.print(productPrices[selectedProduct], 2);
      delay(10);

      // Wait until button 3 is released
      while (digitalRead(buttonPin3) == HIGH) {
        // Check if button 2 is pressed to exit the loop
        if (digitalRead(buttonPin2) == LOW) {
          return;
        }

        if (digitalRead(buttonPin4) == LOW) {
          lcd.setCursor(0, 0);
          lcd.print("Added to Cart");
          lcd.setCursor(0, 1);
          lcd.print("Press 4 for Details");

          // Add your logic to store the item in the cart array
          cartProducts[currentCartItemIndex] = productNames[selectedProduct];
          cartPrices[currentCartItemIndex] = productPrices[selectedProduct];
          currentCartItemIndex++;
          cartItemCount++;

          // Wait until button 4 is released
          while (digitalRead(buttonPin4) == LOW) {
            delay(10);
          }

          delay(500); // Display the message for 2 seconds

          // Clear the screen and go back to the food details
          lcd.clear();
          lcd.setCursor(0, 0);
          lcd.print("Food: ");
          lcd.print(productNames[selectedProduct]);
          lcd.setCursor(0, 1);
          lcd.print("Price: $");
          lcd.print(productPrices[selectedProduct], 2);
        }
        delay(10);
      }
    }
  }
}



void displayShoppingCart() {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Shopping Cart:");

    // Display items in the cart
    for (int i = 0; i < cartItemCount; ++i) {
        lcd.setCursor(0, i + 1);
        lcd.print(cartProducts[i]);
        lcd.setCursor(10, i + 1);
        lcd.print("$");
        lcd.print(cartPrices[i], 2);
    }

    // Display total price
    lcd.setCursor(0, cartItemCount + 1);
    lcd.print("Total: $");
    float total = 0;
    for (int i = 0; i < cartItemCount; ++i) {
        total += cartPrices[i];
    }
    lcd.print(total, 2);

    delay(500); // Display the shopping cart for 0.5 seconds

    // Check if button 2 is pressed to exit the loop
    while (digitalRead(buttonPin2) == HIGH) {
        delay(10);
    }

    // Clear the screen and go back to the food details
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Food: ");
    lcd.print(productNames[selectedProduct]);
    lcd.setCursor(0, 1);
    lcd.print("Price: $");
    lcd.print(productPrices[selectedProduct], 2);
}