using System;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Hncore.Infrastructure.Common;
using Hncore.Infrastructure.Data;
using Hncore.Infrastructure.Extension;
using Hncore.Infrastructure.OpenApi;
using Hncore.Infrastructure.Serializer;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Hncore.Infrastructure.Core.Web;


namespace Hncore.Infrastructure.WebApi
{
    /// <summary>
    /// 统一错误异常处理中间件类
    /// </summary>
    /// 
    public class ErrorHandlingMiddleware
    {
        private readonly RequestDelegate next;

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

        public async Task Invoke(HttpContext context)
        {           
            try
            {
                await next(context);
            }
            catch (Exception ex)
            {
                string requestMsg = "请求URL：" + context.Request.GetAbsoluteUri() + "";

                requestMsg += "\nMethod：" + context.Request.Method + "\n";

                if (context.Request.Method.ToLower() != "get")
                {
                    var requestBody = await context.Request.ReadBodyAsStringAsync();
                    requestMsg += "Body：\n" + requestBody +
                                  "\n------------------------\n";
                }
                else
                {
                    requestMsg += "\n------------------------\n";
                }


                await HandleExceptionAsync(context, ex, requestMsg);
            }
        }


        private static Task HandleExceptionAsync(HttpContext context, Exception ex,
            string requestMsg)
        {
            ResultCode code = ResultCode.C_UNKNOWN_ERROR;
            string msg = "";

            if (ex is BusinessException bex)
            {
                code = bex.Code;
                msg = bex.Message;

                LogHelper.Error($"业务异常，{msg}", requestMsg + ex);
            }
            else
            {
                if (EnvironmentVariableHelper.IsAspNetCoreProduction)
                {
                    msg = "系统繁忙，请稍后再试";
                }
                else
                {
                    msg = ex.Message;
                }

                LogHelper.Error($"未知异常，{ex.Message}", requestMsg + ex);
            }

            var data = new ApiResult(code, msg);

            var result = data.ToJson();

            context.Response.ContentType = "application/json;charset=utf-8";

            return context.Response.WriteAsync(result);
        }
    }

    public static class ErrorHandlingExtensions
    {
        public static IApplicationBuilder UseErrorHandling(this IApplicationBuilder builder)
        {
            return builder.UseMiddleware<ErrorHandlingMiddleware>();
        }
    }
}