feat(shared-web): add shared swagger and tracing utilities

src/Core/TakeoutSaaS.Shared.Web/Middleware/ExceptionHandlingMiddleware.cs

@@ -0,0 +1,86 @@
+using System;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
+using TakeoutSaaS.Shared.Abstractions.Results;
+
+namespace TakeoutSaaS.Shared.Web.Middleware;
+
+/// <summary>
+/// 全局异常处理中间件，将异常统一映射为 ApiResponse。
+/// </summary>
+public sealed class ExceptionHandlingMiddleware
+{
+    private readonly RequestDelegate _next;
+    private readonly ILogger<ExceptionHandlingMiddleware> _logger;
+    private readonly IHostEnvironment _environment;
+
+    private static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
+    };
+
+    public ExceptionHandlingMiddleware(RequestDelegate next, ILogger<ExceptionHandlingMiddleware> logger, IHostEnvironment environment)
+    {
+        _next = next;
+        _logger = logger;
+        _environment = environment;
+    }
+
+    public async Task InvokeAsync(HttpContext context)
+    {
+        try
+        {
+            await _next(context);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "未处理异常：{Message}", ex.Message);
+            await HandleExceptionAsync(context, ex);
+        }
+    }
+
+    private Task HandleExceptionAsync(HttpContext context, Exception exception)
+    {
+        var (statusCode, response) = BuildErrorResponse(exception);
+
+        if (_environment.IsDevelopment())
+        {
+            response = response with
+            {
+                Message = exception.Message,
+                Errors = new
+                {
+                    response.Errors,
+                    detail = exception.ToString()
+                }
+            };
+        }
+
+        context.Response.StatusCode = statusCode;
+        context.Response.ContentType = "application/json";
+        return context.Response.WriteAsJsonAsync(response, SerializerOptions);
+    }
+
+    private static (int StatusCode, ApiResponse<object> Response) BuildErrorResponse(Exception exception)
+    {
+        return exception switch
+        {
+            ValidationException validationException => (
+                StatusCodes.Status422UnprocessableEntity,
+                ApiResponse<object>.Error(ErrorCodes.ValidationFailed, "请求参数验证失败", validationException.Errors)),
+            BusinessException businessException => (
+                StatusCodes.Status422UnprocessableEntity,
+                ApiResponse<object>.Error(businessException.ErrorCode, businessException.Message)),
+            _ => (
+                StatusCodes.Status500InternalServerError,
+                ApiResponse<object>.Error(ErrorCodes.InternalServerError, "服务器开小差啦，请稍后再试"))
+        };
+    }
+}