using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Text;
using System.Web;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace DAL
{
    /// <summary>
    /// 货币汇率接口
    /// </summary>
    public class ExchangeRateAPI
    {
        static string appkey = "0f5429e9fbb8637c0ff3f14bbb42c732"; //配置您申请的appkey

        /// <summary>
        /// 外汇汇率
        /// </summary>
        /// <returns></returns>
        public string ForeignCurrency() 
        {
            string url = "http://web.juhe.cn:8080/finance/exchange/rmbquot";

            var parameters2 = new Dictionary<string, string>();

            parameters2.Add("key", appkey);//你申请的key 
            parameters2.Add("type", "0"); //两种格式(0或者1,默认为0)
            parameters2.Add("bank", "3"); //(0:工商银行,1:招商银行,2:建设银行,3:中国银行,4:交通银行,5:农业银行,默认为:0)

            string result2 = sendPost(url, parameters2, "get");

            JObject jsonText = (JObject)JsonConvert.DeserializeObject(result2);
            string errorCode2 = jsonText["error_code"].ToString();

            if (errorCode2 == "0")
            {
                return jsonText["result"].ToString();
            }
            else
            {
                // return jsonText["error_code"].ToString() + ":" + jsonText["reason"].ToString();
                return "请求超过次数限制!";
            }
        }

        /// <summary>
        /// 雷怡 2022-07-29 14;11
        /// 外汇汇率
        /// </summary>
        /// <returns></returns>
        public string ForeignCurrency1()
        {
            string url = "http://web.juhe.cn:8080/finance/exchange/rmbquot";

            var parameters2 = new Dictionary<string, string>();

            parameters2.Add("key", appkey);//你申请的key 
            parameters2.Add("type", "0"); //两种格式(0或者1,默认为0)
            parameters2.Add("bank", "3"); //(0:工商银行,1:招商银行,2:建设银行,3:中国银行,4:交通银行,5:农业银行,默认为:0)

            string result2 = sendPost(url, parameters2, "get");

            JObject jsonText = (JObject)JsonConvert.DeserializeObject(result2);
            string errorCode2 = jsonText["error_code"].ToString();

            if (errorCode2 == "0")
            {
                return jsonText["result"].ToString();
            }
            else
            {
                return jsonText["error_code"].ToString() + ":" + jsonText["reason"].ToString();
            }
        }


        /// <summary>
        /// Http (GET/POST)
        /// </summary>
        /// <param name="url">请求URL</param>
        /// <param name="parameters">请求参数</param>
        /// <param name="method">请求方法</param>
        /// <returns>响应内容</returns>
        static string sendPost(string url, IDictionary<string, string> parameters, string method)
        {
            if (method.ToLower() == "post")
            {
                HttpWebRequest req = null;
                HttpWebResponse rsp = null;
                System.IO.Stream reqStream = null;
                try
                {
                    req = (HttpWebRequest)WebRequest.Create(url);
                    req.Method = method;
                    req.KeepAlive = false;
                    req.ProtocolVersion = HttpVersion.Version10;
                    req.Timeout = 5000;
                    req.ContentType = "application/x-www-form-urlencoded;charset=utf-8";
                    byte[] postData = Encoding.UTF8.GetBytes(BuildQuery(parameters, "utf8"));
                    reqStream = req.GetRequestStream();
                    reqStream.Write(postData, 0, postData.Length);
                    rsp = (HttpWebResponse)req.GetResponse();
                    Encoding encoding = Encoding.GetEncoding(rsp.CharacterSet);
                    return GetResponseAsString(rsp, encoding);
                }
                catch (Exception ex)
                {
                    return ex.Message;
                }
                finally
                {
                    if (reqStream != null) reqStream.Close();
                    if (rsp != null) rsp.Close();
                }
            }
            else
            {
                //创建请求
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url + "?" + BuildQuery(parameters, "utf8"));

                //GET请求
                request.Method = "GET";
                request.ReadWriteTimeout = 5000;
                request.ContentType = "text/html;charset=UTF-8";
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                Stream myResponseStream = response.GetResponseStream();
                StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));

                //返回内容
                string retString = myStreamReader.ReadToEnd();
                return retString;
            }
        }

        /// <summary>
        /// 组装普通文本请求参数。
        /// </summary>
        /// <param name="parameters">Key-Value形式请求参数字典</param>
        /// <returns>URL编码后的请求数据</returns>
        static string BuildQuery(IDictionary<string, string> parameters, string encode)
        {
            StringBuilder postData = new StringBuilder();
            bool hasParam = false;
            IEnumerator<KeyValuePair<string, string>> dem = parameters.GetEnumerator();
            while (dem.MoveNext())
            {
                string name = dem.Current.Key;
                string value = dem.Current.Value;
                // 忽略参数名或参数值为空的参数
                if (!string.IsNullOrEmpty(name))//&& !string.IsNullOrEmpty(value)
                {
                    if (hasParam)
                    {
                        postData.Append("&");
                    }
                    postData.Append(name);
                    postData.Append("=");
                    if (encode == "gb2312")
                    {
                        postData.Append(HttpUtility.UrlEncode(value, Encoding.GetEncoding("gb2312")));
                    }
                    else if (encode == "utf8")
                    {
                        postData.Append(HttpUtility.UrlEncode(value, Encoding.UTF8));
                    }
                    else
                    {
                        postData.Append(value);
                    }
                    hasParam = true;
                }
            }
            return postData.ToString();
        }

        /// <summary>
        /// 把响应流转换为文本。
        /// </summary>
        /// <param name="rsp">响应流对象</param>
        /// <param name="encoding">编码方式</param>
        /// <returns>响应文本</returns>
        static string GetResponseAsString(HttpWebResponse rsp, Encoding encoding)
        {
            System.IO.Stream stream = null;
            StreamReader reader = null;
            try
            {
                // 以字符流的方式读取HTTP响应
                stream = rsp.GetResponseStream();
                reader = new StreamReader(stream, encoding);
                return reader.ReadToEnd();
            }
            finally
            {
                // 释放资源
                if (reader != null) reader.Close();
                if (stream != null) stream.Close();
                if (rsp != null) rsp.Close();
            }
        }

    }
}