CoreAgent/CoreAgent.Infrastructure/Middleware/ExceptionMiddleware.cs

using CoreAgent.Domain.Exceptions;
using CoreAgent.Domain.Models;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using System.Net;
using System.Text.Json;

namespace CoreAgent.Infrastructure.Middleware
{
    public class ExceptionMiddleware
    {
        private readonly RequestDelegate _next;
        private readonly ILogger<ExceptionMiddleware> _logger;

        public ExceptionMiddleware(RequestDelegate next, ILogger<ExceptionMiddleware> logger)
        {
            _next = next;
            _logger = logger;
        }

        public async Task InvokeAsync(HttpContext context)
        {
            try
            {
                await _next(context);
            }
            catch (Exception ex)
            {
                await HandleExceptionAsync(context, ex);
            }
        }

        private async Task HandleExceptionAsync(HttpContext context, Exception exception)
        {
            var response = context.Response;
            response.ContentType = "application/json";

            var errorResponse = new ErrorResponse
            {
                TraceId = context.TraceIdentifier,
                Message = "An error occurred while processing your request."
            };

            switch (exception)
            {
                case ValidationException validationEx:
                    response.StatusCode = (int)HttpStatusCode.BadRequest;
                    errorResponse.Message = validationEx.Message;
                    errorResponse.Errors = validationEx.Errors;
                    _logger.LogWarning("Validation error: {Message}", validationEx.Message);
                    break;

                case NotFoundException notFoundEx:
                    response.StatusCode = (int)HttpStatusCode.NotFound;
                    errorResponse.Message = notFoundEx.Message;
                    _logger.LogWarning("Resource not found: {Message}", notFoundEx.Message);
                    break;

                case UnauthorizedAccessException:
                    response.StatusCode = (int)HttpStatusCode.Unauthorized;
                    errorResponse.Message = "You are not authorized to access this resource.";
                    _logger.LogWarning("Unauthorized access attempt");
                    break;

                default:
                    response.StatusCode = (int)HttpStatusCode.InternalServerError;
                    _logger.LogError(exception, "Unhandled exception occurred");
                    break;
            }

            var result = JsonSerializer.Serialize(errorResponse);
            await response.WriteAsync(result);
        }
    }
}