Build High-Converting
Online Stores

// Shopping Cart Context with Reducer
import React, { createContext, useReducer, useContext } from 'react';

const CartContext = createContext();

const cartReducer = (state, action) => {
    switch (action.type) {
        case 'ADD_TO_CART':
            const existingItem = state.items.find(
                item => item.id === action.payload.id &&
                item.variant.id === action.payload.variant.id
            );
            
            if (existingItem) {
                return {
                    ...state,
                    items: state.items.map(item =>
                        item.id === action.payload.id ?
                        { ...item, quantity: item.quantity + action.payload.quantity }
                        : item
                    )
                };
            }
            
            return {
                ...state,
                items: [...state.items, action.payload]
            };
            
        case 'REMOVE_FROM_CART':
            return {
                ...state,
                items: state.items.filter(
                    item => !(item.id === action.payload.id &&
                    item.variant.id === action.payload.variant.id)
                )
            };
            
        case 'UPDATE_QUANTITY':
            return {
                ...state,
                items: state.items.map(item =>
                    item.id === action.payload.id ?
                    { ...item, quantity: action.payload.quantity }
                    : item
                )
            };
            
        case 'CLEAR_CART':
            return { ...state, items: [] };
            
        default:
            return state;
    }
};

// Stripe Checkout Integration
<?php

namespace App\Http\Controllers;

use Stripe\Stripe;
use Stripe\Checkout\Session;
use Illuminate\Http\Request;

class CheckoutController extends Controller
{
    public function createCheckoutSession(Request $request)
    {
        Stripe::setApiKey(env('STRIPE_SECRET_KEY'));
        
        $cartItems = $request->input('cart_items');
        $lineItems = [];
        
        foreach ($cartItems as $item) {
            $lineItems[] = [
                'price_data' => [
                    'currency' => 'usd',
                    'product_data' => [
                        'name' => $item['name'],
                        'images' => [$item['image']],
                    ],
                    'unit_amount' => $item['price'] * 100,
                ],
                'quantity' => $item['quantity'],
            ];
        }
        
        $session = Session::create([
            'payment_method_types' => ['card'],
            'line_items' => $lineItems,
            'mode' => 'payment',
            'success_url' => route('checkout.success') . '?session_id={CHECKOUT_SESSION_ID}',
            'cancel_url' => route('checkout.cancel'),
            'customer_email' => $request->user()->email,
            'metadata' => [
                'user_id' => $request->user()->id,
                'order_type' => 'online'
            ]
        ]);
        
        return response()->json([
            'sessionId' => $session->id,
            'publicKey' => env('STRIPE_PUBLIC_KEY')
        ]);
    }
}