本地事件的设计与实现

src/HelloShop.OrderingService/Commands/Orders/CreateOrderCommandHandler.cs

@@ -5,13 +5,14 @@ using AutoMapper;
 using HelloShop.OrderingService.Entities.Buyers;
 using HelloShop.OrderingService.Entities.Orders;
 using HelloShop.OrderingService.Infrastructure;
+using HelloShop.OrderingService.LocalEvents;
 using HelloShop.OrderingService.Services;
 using MediatR;
 using Microsoft.EntityFrameworkCore;
 
 namespace HelloShop.OrderingService.Commands.Orders
 {
-    public class CreateOrderCommandHandler(OrderingServiceDbContext dbContext, IMapper mapper) : IRequestHandler<CreateOrderCommand, bool>
+    public class CreateOrderCommandHandler(IMediator mediator, OrderingServiceDbContext dbContext, IMapper mapper) : IRequestHandler<CreateOrderCommand, bool>
     {
         public async Task<bool> Handle(CreateOrderCommand request, CancellationToken cancellationToken)
         {
@@ -42,6 +43,8 @@ namespace HelloShop.OrderingService.Commands.Orders
             await dbContext.AddAsync(order, cancellationToken);
             await dbContext.SaveChangesAsync(cancellationToken);
 
+            await mediator.Publish(new OrderStartedLocalEvent(order), cancellationToken);
+
             return await Task.FromResult(true);
         }
     }

src/HelloShop.OrderingService/Extensions/Extensions.cs

@@ -33,6 +33,8 @@ namespace HelloShop.OrderingService.Extensions
             });
 
             builder.Services.AddModelMapper().AddModelValidator();
+
+            builder.Services.AddTransient<ISmsSender, MessageService>().AddTransient<IEmailSender, MessageService>();
         }
 
         public static WebApplication MapApplicationEndpoints(this WebApplication app)

src/HelloShop.OrderingService/LocalEvents/EmailWhenOrderStartedLocalEventHandler.cs

@@ -0,0 +1,18 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using HelloShop.OrderingService.Services;
+using MediatR;
+
+namespace HelloShop.OrderingService.LocalEvents
+{
+    public class EmailWhenOrderStartedLocalEventHandler(IEmailSender emailSender) : INotificationHandler<OrderStartedLocalEvent>
+    {
+        public Task Handle(OrderStartedLocalEvent notification, CancellationToken cancellationToken)
+        {
+            emailSender.SendEmailAsync(notification.Order.BuyerId.ToString(), "Order started", $"Your order {notification.Order.Id} has started", cancellationToken);
+
+            return Task.CompletedTask;
+        }
+    }
+}

src/HelloShop.OrderingService/LocalEvents/OrderStartedLocalEvent.cs

@@ -0,0 +1,10 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using HelloShop.OrderingService.Entities.Orders;
+using MediatR;
+
+namespace HelloShop.OrderingService.LocalEvents
+{
+    public record class OrderStartedLocalEvent(Order Order) : INotification;
+}

src/HelloShop.OrderingService/LocalEvents/SmsWhenOrderStartedLocalEventHandler.cs

@@ -0,0 +1,18 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using HelloShop.OrderingService.Services;
+using MediatR;
+
+namespace HelloShop.OrderingService.LocalEvents
+{
+    public class SmsWhenOrderStartedLocalEventHandler(ISmsSender smsSender) : INotificationHandler<OrderStartedLocalEvent>
+    {
+        public Task Handle(OrderStartedLocalEvent notification, CancellationToken cancellationToken)
+        {
+            smsSender.SendSmsAsync(notification.Order.BuyerId.ToString(), $"Your order {notification.Order.Id} has started", cancellationToken);
+
+            return Task.CompletedTask;
+        }
+    }
+}

src/HelloShop.OrderingService/Services/IEmailSender.cs

@@ -0,0 +1,10 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+namespace HelloShop.OrderingService.Services
+{
+    public interface IEmailSender
+    {
+        Task SendEmailAsync(string email, string subject, string message, CancellationToken cancellationToken = default);
+    }
+}

src/HelloShop.OrderingService/Services/ISmsSender.cs

@@ -0,0 +1,10 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+namespace HelloShop.OrderingService.Services
+{
+    public interface ISmsSender
+    {
+        Task SendSmsAsync(string number, string message, CancellationToken cancellationToken = default);
+    }
+}

src/HelloShop.OrderingService/Services/MessageService.cs

@@ -0,0 +1,22 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using Microsoft.Extensions.Logging;
+
+namespace HelloShop.OrderingService.Services
+{
+    public class MessageService(ILogger<MessageService> logger) : IEmailSender, ISmsSender
+    {
+        public Task SendEmailAsync(string email, string subject, string message, CancellationToken cancellationToken = default)
+        {
+            logger.LogInformation("Sending email to {Email} with subject {Subject} and message {Message}", email, subject, message);
+            return Task.CompletedTask;
+        }
+
+        public Task SendSmsAsync(string number, string message, CancellationToken cancellationToken = default)
+        {
+            logger.LogInformation("Sending SMS to {Number} with message {Message}", number, message);
+            return Task.CompletedTask;
+        }
+    }
+}