From 88ccaea826cf79b8cb58baeef0a204c27a7641e1 Mon Sep 17 00:00:00 2001
From: Semikolon <jlp4u@web.de>
Date: Mon, 12 Jun 2023 13:45:54 +0200
Subject: [PATCH] add ExceptionHandlingMiddleware

---
 .../Middleware/ExceptionHandlingMiddleware.cs | 38 +++++++++++++++++++
 AB-API/Program.cs                             |  5 +++
 2 files changed, 43 insertions(+)
 create mode 100644 AB-API/Middleware/ExceptionHandlingMiddleware.cs

diff --git a/AB-API/Middleware/ExceptionHandlingMiddleware.cs b/AB-API/Middleware/ExceptionHandlingMiddleware.cs
new file mode 100644
index 0000000..c32fc02
--- /dev/null
+++ b/AB-API/Middleware/ExceptionHandlingMiddleware.cs
@@ -0,0 +1,38 @@
+using AB.Domain.Exceptions;
+using System.Text.Json;
+
+namespace AB_API.Middleware
+{
+    public class ExceptionHandlingMiddleware : IMiddleware
+    {
+        public async Task InvokeAsync(HttpContext context, RequestDelegate next)
+        {
+            try
+            {
+                await next(context);
+            }
+            catch (Exception ex)
+            {
+                await HandleExceptionAsync(context, ex);
+            }
+        }
+
+        private async Task HandleExceptionAsync(HttpContext httpContext, Exception ex)
+        {
+            httpContext.Response.ContentType = "application/json";
+
+            httpContext.Response.StatusCode = ex switch
+            {
+                NotFoundException => StatusCodes.Status404NotFound,
+                _ => StatusCodes.Status400BadRequest
+            };
+
+            var response = new
+            {
+                error = ex.Message
+            };
+
+            await httpContext.Response.WriteAsJsonAsync(response);
+        }
+    }
+}
diff --git a/AB-API/Program.cs b/AB-API/Program.cs
index 056cbc9..6b2922c 100644
--- a/AB-API/Program.cs
+++ b/AB-API/Program.cs
@@ -3,6 +3,7 @@ using AB.Persistence;
 using AB.Persistence.Repos;
 using AB.Services;
 using AB.Services.Abstractions;
+using AB_API.Middleware;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.OpenApi.Models;
 using System.Text.Json.Serialization;
@@ -31,6 +32,8 @@ builder.Services.AddDbContextPool<RepoDbContext>(builder =>
     builder.UseInMemoryDatabase("test");
 });
 
+builder.Services.AddTransient<ExceptionHandlingMiddleware>();
+
 var app = builder.Build();
 
 // Configure the HTTP request pipeline.
@@ -40,6 +43,8 @@ if (app.Environment.IsDevelopment())
     app.UseSwaggerUI();
 }
 
+app.UseMiddleware<ExceptionHandlingMiddleware>();
+
 app.UseHttpsRedirection();
 
 app.UseAuthorization();