using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using TalentCloud.Base.Utils;
using System.IO;
using System.Text;
using System.Web.Security;
using System.Configuration;
using TalentCloud.Common.Log;

namespace TalentCloud.Agriculture.Weixin.Web
{
    /// <summary>
    /// WeiXinCheckSignature 的摘要说明
    /// </summary>
    public class WeiXinCheckSignature : IHttpHandler
    {
          WeiXinService WeiXinService = new WeiXinService();
         public void ProcessRequest(HttpContext context)
        {
            string postString = string.Empty;
            if (HttpContext.Current.Request.HttpMethod.ToUpper() == "POST")
            {
                using (Stream stream = HttpContext.Current.Request.InputStream)
                {
                    Byte[] postBytes = new Byte[stream.Length];
                    stream.Read(postBytes, 0, (Int32)stream.Length);
                    postString = Encoding.UTF8.GetString(postBytes);
                }

                if (!string.IsNullOrEmpty(postString))
                {
                    ///处理回复信息
                    WeiXinService.ResponseMsg(postString, context);
                }
            }
            else
            {
                Auth(); //微信接入的测试
            }
        }


        /// <summary>
        /// 成为开发者的第一步，验证并相应服务器的数据
        /// </summary>
        private void Auth()
        {
            string token = ConfigurationManager.AppSettings["WeixinToken"].TryToString();//从配置文件获取Token
            if (string.IsNullOrEmpty(token))
            {
                LogHelper.WriteFileLog("WeixinToken", string.Format("WeixinToken 配置项没有配置！"));
            }

            string echoString = HttpContext.Current.Request.QueryString["echoStr"];
            string signature = HttpContext.Current.Request.QueryString["signature"];
            string timestamp = HttpContext.Current.Request.QueryString["timestamp"];
            string nonce = HttpContext.Current.Request.QueryString["nonce"];
            if (CheckSignature(token, signature, timestamp, nonce))
            {
                if (!string.IsNullOrEmpty(echoString))
                {
                    HttpContext.Current.Response.Write(echoString);
                    HttpContext.Current.Response.End();
                }
            }
        }


        /// <summary>
        /// 验证微信签名
        /// </summary>
        public bool CheckSignature(string token, string signature, string timestamp, string nonce)
        {
            string[] ArrTmp = { token, timestamp, nonce };

            Array.Sort(ArrTmp);
            string tmpStr = string.Join("", ArrTmp);

            tmpStr = FormsAuthentication.HashPasswordForStoringInConfigFile(tmpStr, "SHA1");
            tmpStr = tmpStr.ToLower();

            if (tmpStr == signature)
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}