using System.Text.Json;
using mws.backend.dotnet.application.Common;

namespace mws.backend.dotnet.api.Middleware;

public class ApiExceptionMiddleware(RequestDelegate next, ILogger<ApiExceptionMiddleware> logger)
{
    public async Task InvokeAsync(HttpContext context)
    {
        try
        {
            await next(context);
        }
        catch (Exception ex)
        {
            await HandleAsync(context, ex);
        }
    }

    private async Task HandleAsync(HttpContext context, Exception ex)
    {
        var (statusCode, message) = ex switch
        {
            BadRequestException => (StatusCodes.Status400BadRequest, ex.Message),
            UnauthorizedException => (StatusCodes.Status401Unauthorized, ex.Message),
            ForbiddenException => (StatusCodes.Status403Forbidden, ex.Message),
            NotFoundException => (StatusCodes.Status404NotFound, ex.Message),
            StorageUnavailableException => (StatusCodes.Status502BadGateway, "Storage backend is unavailable. Please try again."),
            _ => (StatusCodes.Status500InternalServerError, "An unexpected error occurred"),
        };

        if (statusCode == StatusCodes.Status500InternalServerError)
        {
            logger.LogError(ex, "Unhandled exception in {Path}", context.Request.Path);
        }

        context.Response.StatusCode = statusCode;
        context.Response.ContentType = "application/json";
        await context.Response.WriteAsync(JsonSerializer.Serialize(new { message }));
    }
}

public static class ApiExceptionMiddlewareExtensions
{
    public static IApplicationBuilder UseApiExceptionMiddleware(this IApplicationBuilder app)
        => app.UseMiddleware<ApiExceptionMiddleware>();
}