MireaBackend/Endpoint/Configuration/Core/Middleware/CustomExceptionHandlerMiddleware.cs

using FluentValidation;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Mirea.Api.DataAccess.Application.Common.Exceptions;
using Mirea.Api.Dto.Responses;
using Mirea.Api.Endpoint.Common.Exceptions;
using System;
using System.Text.Json;
using System.Threading.Tasks;

namespace Mirea.Api.Endpoint.Configuration.Core.Middleware;

public class CustomExceptionHandlerMiddleware(RequestDelegate next, ILogger<CustomExceptionHandlerMiddleware> logger)
{
    public async Task InvokeAsync(HttpContext context)
    {
        try
        {
            await next(context);
        }
        catch (Exception exception)
        {
            await HandleExceptionAsync(context, exception);
        }
    }

    private Task HandleExceptionAsync(HttpContext context, Exception exception)
    {
        var code = StatusCodes.Status500InternalServerError;
        var result = string.Empty;
        switch (exception)
        {
            case ValidationException validationException:
                code = StatusCodes.Status400BadRequest;
                result = JsonSerializer.Serialize(new ErrorResponse()
                {
                    Error = validationException.Message,
                    Code = code
                });
                break;
            case NotFoundException:
                code = StatusCodes.Status404NotFound;
                break;
            case ControllerArgumentException:
                code = StatusCodes.Status400BadRequest;
                break;
        }

        context.Response.ContentType = "application/json";
        context.Response.StatusCode = code;

        if (!string.IsNullOrEmpty(result))
            return context.Response.WriteAsync(result);

        string error;
        if (code == StatusCodes.Status500InternalServerError)
        {
            error = "Internal Server Error";
            logger.LogError(exception, "Internal server error when processing the request");
        }
        else
            error = exception.Message;

        result = JsonSerializer.Serialize(new ErrorResponse()
        {
            Error = error,
            Code = code
        });

        return context.Response.WriteAsync(result);
    }
}