using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using System.Threading.Tasks;
using System;
using System.Text.Json;
using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.Logging;
using Utility.Entity;
using Newtonsoft.Json;

namespace Utility
{
    public class CustomerExceptionMiddleware
    {
        private readonly RequestDelegate _next;
        private readonly ILogger<CustomerExceptionMiddleware> _logger;

        public CustomerExceptionMiddleware(RequestDelegate next, ILogger<CustomerExceptionMiddleware> logger)
        {
            _next = next;
            _logger = logger;
        }

        public async Task Invoke(HttpContext context)
        {
            try
            {
                await _next(context);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, ex.Message);
                context.Response.ContentType = "application/json";
                context.Response.StatusCode = StatusCodes.Status500InternalServerError;
                var result = "系统异常，请联系管理员";
                if (ex is AppFriendlyException)
                    result = ex.Message;
                var apiResponse = new ApiResponse<object>(
                        code: (int)ResponseEnum.Error,
                        message: result,
                        data: result
                    );

                await context.Response.WriteAsync(JsonConvert.SerializeObject(apiResponse));
            }
        }
    }

    /// <summary>
    /// 静态类
    /// </summary>
    public static class ExceptionMiddlewareExtension
    {
        /// <summary>
        /// 静态方法
        /// </summary>
        /// <param name="app">要进行扩展的类型</param>
        public static void UseExceptionMiddleware(this IApplicationBuilder app)
        {
            app.UseMiddleware(typeof(CustomerExceptionMiddleware));
        }
    }
}