using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Web;
using System.Xml;

namespace SiteCore.Alipay
{
    /// <summary>
    /// 功能：支付宝接口公用函数类
    /// 详细：该类是请求、通知返回两个文件所调用的公用函数核心处理文件，不需要修改
    /// 版本：3.1
    /// 修改日期：2010-10-29
    /// 说明：
    /// 以下代码只是为了方便商户测试而提供的样例代码，商户可以根据自己网站的需要，按照技术文档编写,并非一定要使用该代码。
    /// 该代码仅供学习和研究支付宝接口使用，只是提供一个参考。
    /// </summary>
    public class AlipayFunction
    {
        /// <summary>
        /// 生成签名结果
        /// </summary>
        /// <param name="sArray">要签名的数组</param>
        /// <param name="key">安全校验码</param>
        /// <param name="sign_type">签名类型</param>
        /// <param name="_input_charset">编码格式</param>
        /// <returns>签名结果字符串</returns>
        public static string Build_mysign(Dictionary<string, string> dicArray, string key, string sign_type, string _input_charset)
        {
            string prestr = Create_linkstring(dicArray);  //把数组所有元素，按照“参数=参数值”的模式用“&”字符拼接成字符串
            //去掉最後一個&字符
            int nLen = prestr.Length;
            prestr = prestr.Substring(0, nLen - 1);

            prestr = prestr + key;                      //把拼接后的字符串再与安全校验码直接连接起来
            string mysign = Sign(prestr, sign_type, _input_charset);	//把最终的字符串签名，获得签名结果

            return mysign;
        }

        /// <summary>
        /// 把数组所有元素，按照“参数=参数值”的模式用“&”字符拼接成字符串
        /// </summary>
        /// <param name="sArray">需要拼接的数组</param>
        /// <returns>拼接完成以后的字符串</returns>
        public static string Create_linkstring(Dictionary<string, string> dicArray)
        {
            StringBuilder prestr = new StringBuilder();
            foreach (KeyValuePair<string, string> temp in dicArray)
            {
                prestr.Append(temp.Key + "=" + temp.Value + "&");
            }
            return prestr.ToString();
        }

        /// <summary>
        /// 把数组所有元素，按照“参数=参数值”的模式用“&”字符拼接成字符串，并对参数值做urlencode
        /// </summary>
        /// <param name="sArray">需要拼接的数组</param>
        /// <param name="code">字符编码</param>
        /// <returns>拼接完成以后的字符串</returns>
        public static string CreateLinkStringUrlencode(Dictionary<string, string> dicArray, Encoding code)
        {
            StringBuilder prestr = new StringBuilder();
            foreach (KeyValuePair<string, string> temp in dicArray)
            {
                prestr.Append(temp.Key + "=" + HttpUtility.UrlEncode(temp.Value, code) + "&");
            }

            //去掉最後一個&字符
            int nLen = prestr.Length;
            prestr.Remove(nLen - 1, 1);

            return prestr.ToString();
        }

        /// <summary>
        /// 除去数组中的空值和签名参数并以字母a到z的顺序排序
        /// </summary>
        /// <param name="dicArrayPre">过滤前的参数组</param>
        /// <returns>过滤后的参数组</returns>
        public static Dictionary<string, string> Para_filter(SortedDictionary<string, string> dicArrayPre)
        {
            Dictionary<string, string> dicArray = new Dictionary<string, string>();
            foreach (KeyValuePair<string, string> temp in dicArrayPre)
            {
                if (temp.Key.ToLower() != "sign" && temp.Key.ToLower() != "sign_type" && temp.Value != "")
                {
                    dicArray.Add(temp.Key.ToLower(), temp.Value);
                }
            }

            return dicArray;
        }

        /// <summary>
        /// 签名字符串
        /// </summary>
        /// <param name="prestr">需要签名的字符串</param>
        /// <param name="sign_type">签名类型</param>
        /// <param name="_input_charset">编码格式</param>
        /// <returns>签名结果</returns>
        public static string Sign(string prestr, string sign_type, string _input_charset)
        {
            StringBuilder sb = new StringBuilder(32);
            if (sign_type.ToUpper() == "MD5")
            {
                MD5 md5 = new MD5CryptoServiceProvider();
                byte[] t = md5.ComputeHash(Encoding.GetEncoding(_input_charset).GetBytes(prestr));
                for (int i = 0; i < t.Length; i++)
                {
                    sb.Append(t[i].ToString("x").PadLeft(2, '0'));
                }
            }
            return sb.ToString();
        }

        /// <summary>
        /// 写日志，方便测试（看网站需求，也可以改成把记录存入数据库）
        /// </summary>
        /// <param name="sPath">日志的本地绝对路径</param>
        /// <param name="sWord">要写入日志里的文本内容</param>
        public static void log_result(string sPath, string sWord)
        {
            StreamWriter fs = new StreamWriter(sPath, false, Encoding.Default);
            fs.Write(sWord);
            fs.Close();
        }

        /// <summary>
        /// 用于防钓鱼，调用接口query_timestamp来获取时间戳的处理函数
        /// 注意：远程解析XML出错，与IIS服务器配置有关
        /// </summary>
        /// <param name="partner">合作身份者ID</param>
        /// <returns>时间戳字符串</returns>
        public static string Query_timestamp(string partner)
        {
            string url = "https://mapi.alipay.com/gateway.do?service=query_timestamp&partner=" + partner;
            string encrypt_key = "";
            XmlTextReader Reader = new XmlTextReader(url);
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(Reader);
            encrypt_key = xmlDoc.SelectSingleNode("/alipay/response/timestamp/encrypt_key").InnerText;
            return encrypt_key;
        }


        /// <summary>
        /// 获取支付宝POST过来通知消息，并以“参数名=参数值”的形式组成数组
        /// </summary>
        /// <returns>request回来的信息组成的数组</returns>
        public static SortedDictionary<string, string> GetRequestPost(HttpContext context)
        {
            int i = 0;
            SortedDictionary<string, string> sArray = new SortedDictionary<string, string>();
            NameValueCollection coll;
            //Load Form variables into NameValueCollection variable.
            coll = context.Request.Form;

            // Get names of all forms into a string array.
            String[] requestItem = coll.AllKeys;

            for (i = 0; i < requestItem.Length; i++)
            {
                sArray.Add(requestItem[i], context.Request.Form[requestItem[i]]);
            }

            return sArray;
        }



        

    }
}