cart

CartReducer.jsx

const cartReducer = (state = {
    cartItems: 0,
    items: products,
    cartContents: [],
}, action) => {
    switch (action.type) {
        case "ADD_TO_CART":
            {
                const existingItem = state.cartContents.find(item => {
                    return item.id === Number(action.payload);
                })
                let newCartContents;
                if (existingItem) {
                    newCartContents = state.cartContents.map(item => {
                        if (item.id === Number(action.payload)) {
                            return {...item, count: item.count + 1 }
                        }
                        return item;
                    });
                } else {
                    newCartContents = [
                        ...state.cartContents,
                        state.items[action.payload],
                    ];
                }
                state = {
                    ...state,
                    cartItems: state.cartItems + 1,
                    cartContents: newCartContents,
                };
            }
            break;
        case "SUBTRACT_ITEM":
            {
                let id = Number(action.payload);
                if (state.cartContents[id].count === 0) {
                    return state
                } else {
                    let subtractItem = state.cartContents.map(item => {
                        if (item.id === Number(action.payload)) {
                            if (item.count === 0) {
                                return item
                            } else
                                return {...item, count: item.count - 1 }
                        }
                        return item;
                    });
                    state = {
                        ...state,
                        cartItems: state.cartItems === 0 ? state.cartItems : state.cartItems - 1,
                        cartContents: subtractItem,
                    }
                };
            }
            break;
        case "ADD_ITEM":
            {
                let addItem = state.cartContents.map(item => {
                    if (item.id === Number(action.payload)) {
                        return {...item, count: item.count + 1 }
                    }
                    return item;
                });
                state = {
                    ...state,
                    cartItems: state.cartItems + 1,
                    cartContents: addItem,
                };
            };
            break;
        default:
    }
    return state;
};