Function StateContext

context/StateContext2.js:6–101

({children})

const Context = createContext();

export const StateContext = ({children}) => {
    const [showCart, setShowCart] = useState(false);
    const [cartItems, setCartItems] = useState([]);
    const [totalPrice, setTotalPrice] = useState();
    const [totalQty, setTotalQty] = useState(0);
    const [qty, setQty] = useState(1);

    let foundProduct;
    let index;

    const onAdd = (product, quantity) => {
        // check if product already in the cart
        const checkProductInCart = cartItems.find((item) => item._id === product._id);
        
        setTotalPrice((prevTotalPrice) => prevTotalPrice + product.price * quantity);
        setTotalQty((prevTotalQty) => prevTotalQty + quantity);

        // if product already in cart, then increase the qty of product instead of add the same product in cart
        if(checkProductInCart) {
            // update the actual item in the cart
            const updatedCartItems = cartItems.map((cartProduct) => {
                if(cartProduct._id === product._id) return {
                    ...cartProduct,
                    quantity: cartProduct.quantity + quantity
                }
            })

            setCartItems(updatedCartItems);
        } else {
            // if when dont have the item in the cart
            product.quantity = quantity;
            setCartItems([...cartItems, {...product}]);
        }
        toast.success(`${qty} ${product.name} added to the cart`);
    }

    const onRemove = (product) => {
        foundProduct = cartItems.find((item) => item._id === product._id)
        const AddNewCartItems = cartItems.filter(item => item._id !== product._id);

        setTotalPrice(prevTotalPrice => prevTotalPrice - foundProduct.price * foundProduct.quantity)
        setTotalQty(prevTotalQty => prevTotalQty - foundProduct.quantity);
        setCartItems(AddNewCartItems);
    }

    const toggleCartItemQuantity = (id, value) => {
        foundProduct = cartItems.find((item) => item._id === id)
        index = cartItems.findIndex((product) => product._id === id)
        const AddNewCartItems = cartItems.filter(item => item._id !== id);

        if(value === 'inc') {
            let newCartItems = [...AddNewCartItems, {...foundProduct, quantity: foundProduct.quantity + 1}]
            setCartItems(newCartItems);
            setTotalPrice(prevTotalPrice => prevTotalPrice + foundProduct.price)
            setTotalQty(prevTotalQty => prevTotalQty + 1)
        } else if(value === 'dec') {
            if(foundProduct.quantity > 1) {
                let newCartItems = [...AddNewCartItems, {...foundProduct, quantity: foundProduct.quantity - 1}]