annotations/src/Middleware/ErrorHandlingMiddleware.cs

using System.Net;
using System.Text.Json;

namespace Azaion.Annotations.Middleware;

public class ErrorHandlingMiddleware(RequestDelegate next, ILogger<ErrorHandlingMiddleware> logger)
{
    public async Task Invoke(HttpContext context)
    {
        try
        {
            await next(context);
        }
        catch (KeyNotFoundException ex)
        {
            await WriteError(context, HttpStatusCode.NotFound, ex.Message);
        }
        catch (ArgumentException ex)
        {
            await WriteError(context, HttpStatusCode.BadRequest, ex.Message);
        }
        catch (InvalidOperationException ex)
        {
            await WriteError(context, HttpStatusCode.Conflict, ex.Message);
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "Unhandled exception");
            await WriteError(context, HttpStatusCode.InternalServerError, "Internal server error");
        }
    }

    private static async Task WriteError(HttpContext context, HttpStatusCode code, string message)
    {
        context.Response.StatusCode = (int)code;
        context.Response.ContentType = "application/json";
        var body = JsonSerializer.Serialize(new { statusCode = (int)code, message });
        await context.Response.WriteAsync(body);
    }
}