using Microsoft.AspNetCore.Http;
using Newtonsoft.Json;
using System;
using System.IO;
using System.Threading.Tasks;
using Thea;
using Thea.ExceptionEx;
using Thea.Web;

public class TheaWebMiddleware
{
    private readonly RequestDelegate next;

    public TheaWebMiddleware(RequestDelegate next)
    {
        this.next = next;
    }

    public async Task Invoke(HttpContext context)
    {
        // SignalR 放行
        if (context.GetEndpoint()?.Metadata?.GetMetadata<SignalREndpointAttribute>() != null)
        {
            await next(context);
            return;
        }

        CommonResponse result = null;
        var statusCode = 200;

        try
        {
            await next(context);

            if (context.Response.StatusCode == 200)
            {
                if (context.Response.Body.Length != 0)
                {
                    //有数据时直接返回
                    //当前代码没有处理通用结构，此处直接返回即可
                    //如果需要处理通用结构则需要在此处增加
                    return;
                }
                else
                {
                    //无任何数据返回时返回通用的成功结构
                    result = CommonResponse.Success;
                }
            }
            else
            {
                statusCode = context.Response.StatusCode;
                result = CommonResponse.Fail(statusCode, statusCode.ToString());
            }
        }
        catch (Exception ex)
        {
            var exception = ex.InnerException ?? ex;
            result = BuildErrorResponse(exception, 200);
        }

        var json = JsonConvert.SerializeObject(result);
        context.Response.Clear();
        context.Response.StatusCode = statusCode;
        await context.Response.WriteAsJsonAsync(json);
    }

    private static CommonResponse BuildErrorResponse(Exception exception, int statusCode)
    {
        if (exception is LevelException levelEx)
        {
            var exConfig = LevelExceptionConfig.GetConfig(levelEx);
            return CommonResponse.Fail((int)ErrorLevel.LangageInfo, levelEx.Message, exConfig);
        }
        return CommonResponse.Fail(statusCode, exception.Message);
    }
}