// 導(dǎo)入相關(guān)包
import java.util.List;

// 領(lǐng)域?qū)嶓w
public class Order {
    private List<OrderItem> items;
    private String customerName;
    private String shippingAddress;

    public Order(String customerName, String shippingAddress) {
        this.customerName = customerName;
        this.shippingAddress = shippingAddress;
    }

    public void addItem(OrderItem item) {
        items.add(item);
    }

    public List<OrderItem> getItems() {
        return items;
    }

    public String getCustomerName() {
        return customerName;
    }

    public String getShippingAddress() {
        return shippingAddress;
    }
}

// 值對象
public class OrderItem {
    private String productName;
    private int quantity;
    private double price;

    public OrderItem(String productName, int quantity, double price) {
        this.productName = productName;
        this.quantity = quantity;
        this.price = price;
    }

    public String getProductName() {
        return productName;
    }

    public int getQuantity() {
        return quantity;
    }

    public double getPrice() {
        return price;
    }
}

// 領(lǐng)域服務(wù)
public class OrderService {
    private OrderRepository orderRepository;

    public OrderService(OrderRepository orderRepository) {
        this.orderRepository = orderRepository;
    }

    public Order createOrder(String customerName, String shippingAddress) {
        Order order = new Order(customerName, shippingAddress);
        orderRepository.save(order);
        return order;
    }

    public void addItemToOrder(int orderId, OrderItem item) {
        Order order = orderRepository.findById(orderId).orElseThrow(() -> new IllegalArgumentException("Order not found"));
        order.addItem(item);
        orderRepository.save(order);
    }
}

// 領(lǐng)域事件
public class OrderCreatedEvent {
    private Order order;

    public OrderCreatedEvent(Order order) {
        this.order = order;
    }

    public Order getOrder() {
        return order;
    }
}

// 訂單倉庫接口
public interface OrderRepository {
    void save(Order order);
    Optional<Order> findById(int id);
}