UniVerse/backend/UniVerse.Api/Middleware/ExceptionHandlingMiddleware.cs

using System.Net;
using System.Text.Json;
using UniVerse.Domain.Exceptions;

namespace UniVerse.Api.Middleware;

public class ExceptionHandlingMiddleware
{
    private readonly RequestDelegate _next;
    private readonly ILogger<ExceptionHandlingMiddleware> _logger;

    public ExceptionHandlingMiddleware(RequestDelegate next, ILogger<ExceptionHandlingMiddleware> 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 (statusCode, title) = exception switch
        {
            BadRequestException => ((int)HttpStatusCode.BadRequest, "Bad Request"),
            NotFoundException => ((int)HttpStatusCode.NotFound, "Not Found"),
            ForbiddenException => ((int)HttpStatusCode.Forbidden, "Forbidden"),
            ConflictException => ((int)HttpStatusCode.Conflict, "Conflict"),
            UnauthorizedAccessException => ((int)HttpStatusCode.Unauthorized, "Unauthorized"),
            _ => ((int)HttpStatusCode.InternalServerError, "Internal Server Error")
        };

        if (statusCode == 500)
            _logger.LogError(exception, "Unhandled exception");
        else
            _logger.LogWarning("Handled exception: {Message}", exception.Message);

        context.Response.ContentType = "application/problem+json";
        context.Response.StatusCode = statusCode;

        var problem = new
        {
            type = $"https://httpstatuses.com/{statusCode}",
            title,
            status = statusCode,
            detail = exception.Message,
            traceId = context.TraceIdentifier
        };

        await context.Response.WriteAsync(JsonSerializer.Serialize(problem,
            new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase }));
    }
}