package mxdx2;

//订单流程编排器（状态模式）
public class orchestration {
 private State currentState;
 private String orderId;
 private ServiceGateway gateway;

 public orchestration(ServiceGateway gateway) {
     this.gateway = gateway;
     this.currentState = new InitState(this);
 }

 // 启动订单流程
 public void startProcess(String token, String userId, String productId) {
     currentState.process(token, userId, productId);
 }

 // 状态变更
 public void setState(State state) {
     this.currentState = state;
 }

 // 获取网关
 public ServiceGateway getGateway() {
     return gateway;
 }

 // 设置订单ID
 public void setOrderId(String orderId) {
     this.orderId = orderId;
 }

 // 状态接口
 public interface State {
     void process(String token, String userId, String productId);
 }

 // 初始状态
 public static class InitState implements State {
     private orchestration orchestrator;

     public InitState(orchestration orchestrator) {
         this.orchestrator = orchestrator;
     }

     @Override
     public void process(String token, String userId, String productId) {
         System.out.println("Starting order process...");
         // 检查用户
         String user = orchestrator.getGateway().getUser(token, userId);
         if (user == null) {
             throw new RuntimeException("User not found");
         }
         // 检查商品
         String product = orchestrator.getGateway().getProduct(token, productId);
         if (product == null) {
             throw new RuntimeException("Product not found");
         }
         // 进入下一个状态
         orchestrator.setState(new CreateOrderState(orchestrator));
         orchestrator.currentState.process(token, userId, productId);
     }
 }

 // 创建订单状态
 public static class CreateOrderState implements State {
     private orchestration orchestrator;

     public CreateOrderState(orchestration orchestrator) {
         this.orchestrator = orchestrator;
     }

     @Override
     public void process(String token, String userId, String productId) {
         System.out.println("Creating order...");
         String orderId = orchestrator.getGateway().createOrder(token, userId, productId);
         orchestrator.setOrderId(orderId);
         // 进入完成状态
         orchestrator.setState(new CompleteState(orchestrator));
         orchestrator.currentState.process(token, userId, productId);
     }
 }

 // 完成状态
 public static class CompleteState implements State {
     private orchestration orchestrator;

     public CompleteState(orchestration orchestrator) {
         this.orchestrator = orchestrator;
     }

     @Override
     public void process(String token, String userId, String productId) {
         System.out.println("Order process completed. Order ID: " + orchestrator.orderId);
     }
 }
}