#include <LiquidCrystal.h>
#include <Wire.h>


#define MAX_STRING_LENGTH 15
#define MAX_CART_ITEMS 10

// LCD Pin Configuration
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

// Define button pins
int buttonScroll = 13, buttonAdd = 10, buttonSubmit = 8;

// I2C Address
int address = 9;

// MenuItem Structure
struct MenuItem {
    char itemName[MAX_STRING_LENGTH];
    char itemPrice[MAX_STRING_LENGTH];
};

// Menu items array
const char ITEM_PRICE[] = "9.99";
MenuItem menuItems[10] = {
    {"Item 1", ITEM_PRICE},
    {"Item 2", ITEM_PRICE},
    {"Item 3", ITEM_PRICE},
    {"Item 4", ITEM_PRICE},
    {"Item 5", ITEM_PRICE},
    {"Item 6", ITEM_PRICE},
    {"Item 7", ITEM_PRICE},
    {"Item 8", ITEM_PRICE},
    {"Item 9", ITEM_PRICE},
    {"Item 10", ITEM_PRICE}
};

// Cart array
MenuItem cart[MAX_CART_ITEMS];
int cartItemCount = 0;
int currentItemIndex = 0; // Current item index for the menu

void setup() {
    Serial.begin(9600);
    Wire.begin();

    // Initialize buttons
    pinMode(buttonScroll, INPUT);
    pinMode(buttonAdd, INPUT);
    pinMode(buttonSubmit, INPUT);

    // Initialize LCD
    lcd.begin(16, 2); // Adjust the size as per your LCD
    lcd.print(menuItems[currentItemIndex].itemName);
}

void loop() {

    handleMenu();

if (digitalRead(buttonSubmit) == HIGH) {
    displayCartContents();
    Wire.beginTransmission(address);
    for (int i = 0; i < cartItemCount; i++) {
        for (size_t j = 0; j < MAX_STRING_LENGTH; j++) {
            Wire.write(cart[i].itemName[j]);
        }
        for (size_t j = 0; j < MAX_STRING_LENGTH; j++) {
            Wire.write(cart[i].itemPrice[j]);
        }
    }
    Wire.endTransmission();
    
    lcd.clear();
    lcd.print("Cart submitted");
    delay(1000); // Display message for a while

    // Optionally clear the cart after submitting
    cartItemCount = 0;
}


    // Requesting data from slave
    int x = 0;
    Wire.requestFrom(address, 1);
    while (Wire.available()) {
        x = Wire.read();
    }
}


void handleMenu() {
    // Scroll through menu items
    if (digitalRead(buttonScroll) == HIGH) {
        lcd.clear();
        currentItemIndex = (currentItemIndex + 1) % 10;
        lcd.print(menuItems[currentItemIndex].itemName);
        delay(200); // Debouncing
    }

    // Add item to cart
    if (digitalRead(buttonAdd) == HIGH) {
       addItemToCart();
    }
}


void addItemToCart() {
    Serial.println("Attempting to add item to cart...");
    if (cartItemCount < MAX_CART_ITEMS) {
        cart[cartItemCount] = menuItems[currentItemIndex];
        Serial.println(menuItems[currentItemIndex]);
        Serial.println(cartItemCount);
        cartItemCount++;
        lcd.clear();
        lcd.print("Added: ");
        lcd.print(menuItems[currentItemIndex].itemName);
        Serial.println("Item added to cart");
        
    } else {
        lcd.clear();
        lcd.print("Cart full");
        Serial.println("Cart is full, can't add more items");
        Serial.println(cartItemCount);
    }
}


void displayCartContents() {
    lcd.clear();
    for (int i = 0; i < cartItemCount; i++) {
        lcd.setCursor(0, 0); // Set cursor to first line
        lcd.print("Item: ");
        lcd.print(cart[i].itemName);
        
        lcd.setCursor(0, 1); // Set cursor to second line
        lcd.print("Price: ");
        lcd.print(cart[i].itemPrice);
        
        delay(2000); // Display each item for 2 seconds
        lcd.clear(); // Clear LCD for the next item
    }
}