Order-to-Cash End-to-End Case Study

package at.aydinsude.enterprise.order.application;

import at.aydinsude.enterprise.order.domain.*;
import java.time.Clock;

// Pattern: Application Service - orchestriert genau einen fachlichen Use Case.
// Pattern: Port-and-Adapter - nutzt RepositoryPort und EventPublisherPort statt Framework-Abhängigkeiten.
public final class PlaceOrderUseCase {
    private final OrderRepositoryPort orders;
    private final CustomerRiskPort customerRisk;
    private final EventPublisherPort events;
    private final Clock clock;

    public PlaceOrderUseCase(OrderRepositoryPort orders,
                             CustomerRiskPort customerRisk,
                             EventPublisherPort events,
                             Clock clock) {
        this.orders = orders;
        this.customerRisk = customerRisk;
        this.events = events;
        this.clock = clock;
    }

    public OrderId handle(PlaceOrderCommand command) {
        if (orders.existsByIdempotencyKey(command.idempotencyKey())) {
            return orders.findOrderIdByIdempotencyKey(command.idempotencyKey());
        }
        customerRisk.assertCustomerMayOrder(command.customerId(), command.total());
        Order order = Order.place(command.customerId(), command.lines(), command.idempotencyKey(), clock.instant());
        orders.save(order);
        events.publishAll(order.pullDomainEvents());
        return order.id();
    }
}