public-valetax/Middleware/ExceptionHandlingMiddleware.cs

using System.Text.Json;
using public_valetax.Exceptions;
using public_valetax.Repositories;

namespace public_valetax.Middleware
{
    public class ExceptionHandlingMiddleware(RequestDelegate _next, ILogger<ExceptionHandlingMiddleware> _logger)
    {
        public async Task InvokeAsync(HttpContext context, IJournalRepository journalRepository)
        {
            try
            {
                if (context.Request.ContentLength > 0)
                {
                    context.Request.EnableBuffering();
                }
                await _next(context);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "An unhandled exception occurred");

                // Generate event ID
                var eventId = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();

                // Capture request details
                var queryParameters = context.Request.QueryString.ToString();
                string? bodyParameters = null;
                
                // Try to capture body parameters (be careful not to consume the stream multiple times)
                if (context.Request.ContentLength > 0)
                {
                    context.Request.Body.Position = 0; // Reset for next middleware
                    using var reader = new StreamReader(context.Request.Body, leaveOpen: true);
                    bodyParameters = await reader.ReadToEndAsync();
                    context.Request.Body.Position = 0; // Reset for next middleware
                }

                // Log to journal
                await journalRepository.CreateJournalEntryAsync(
                    eventId,
                    ex.GetType().Name,
                    ex.Message,
                    queryParameters,
                    bodyParameters,
                    ex.StackTrace);

                // Handle specific exception types
                await HandleExceptionAsync(context, ex, eventId);
            }
        }

        private static async Task HandleExceptionAsync(HttpContext context, Exception exception, long eventId)
        {
            var response = new
            {
                type = exception is SecureException ? "Secure" : "Exception",
                id = eventId.ToString(),
                data = new
                {
                    message = exception is SecureException 
                        ? exception.Message 
                        : $"Internal server error ID = {eventId}"
                }
            };

            context.Response.ContentType = "application/json";
            context.Response.StatusCode = StatusCodes.Status500InternalServerError;

            var jsonResponse = JsonSerializer.Serialize(response);
            await context.Response.WriteAsync(jsonResponse);
        }
    }
}