using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Security;
using System.Net;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Threading.Tasks;

namespace DS.Module.DjyRulesEngine
{
    /// <summary>
    /// 大简云规则引擎服务封装请求工具类
    /// </summary>
    public class RuleEngineHttpUtil
    {

        /// 平台ip
        /// </summary>
        private static string _ip;

        /// <summary>
        /// 平台端口
        /// </summary>
        private static int _port = 443;

        /// <summary>
        /// 平台APPKey
        /// </summary>
        private static string _appkey;

        /// <summary>
        /// 平台APPSecret
        /// </summary>
        private static string _secret;

        /// <summary>
        /// 是否使用HTTPS协议
        /// </summary>
        private static bool _isHttps = true;

        /// <summary>
        /// 设置信息参数
        /// </summary>
        /// <param name="appkey">合作方APPKey</param>
        /// <param name="secret">合作方APPSecret</param>
        /// <param name="ip">平台IP</param>
        /// <param name="port">平台端口，默认HTTPS的443端口</param>
        /// <param name="isHttps">是否启用HTTPS协议，默认HTTPS</param>
        /// <return></return>  string appkey, string secret, 
        public static void SetPlatformInfo(string ip, int port = 443, bool isHttps = true)
        {
            //_appkey = appkey;
            //_secret = secret;
            _ip = ip;
            _port = port;
            _isHttps = isHttps;

            // 设置并发数，如不设置默认为2
            ServicePointManager.DefaultConnectionLimit = 512;
        }
        /// <summary>
        /// HTTP GET请求
        /// </summary>
        /// <param name="uri">HTTP接口Url，不带协议和端口，如/artemis/api/resource/v1/cameras/indexCode?cameraIndexCode=a10cafaa777c49a5af92c165c95970e0</param>
        /// <param name="timeout">请求超时时间，单位：秒</param>
        /// <returns></returns>
        public static string HttpGet(string uri, int timeout)
        {
            Dictionary<string, string> header = new Dictionary<string, string>();

            // 初始化请求：组装请求头，设置远程证书自动验证通过
            initRequest(header, uri, "", false);

            // build web request object
            StringBuilder sb = new StringBuilder();
            sb.Append(_isHttps ? "https://" : "http://").Append(_ip).Append(":").Append(_port.ToString()).Append(uri);

            HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(sb.ToString());
            req.KeepAlive = false;
            req.ProtocolVersion = HttpVersion.Version11;
            req.AllowAutoRedirect = false;   // 不允许自动重定向
            req.Method = "GET";
            req.Timeout = timeout * 1000;    // 传入是秒，需要转换成毫秒
            req.Accept = header["Accept"];
            req.ContentType = header["Content-Type"];

            foreach (string headerKey in header.Keys)
            {
                if (headerKey.Contains("USER_KEY"))
                {
                    req.Headers.Add(headerKey + ":" + header[headerKey]);
                }
                if (headerKey.Contains("USER_SECRET"))
                {
                    req.Headers.Add(headerKey + ":" + header[headerKey]);
                }
                //if (headerKey.Contains("sign"))
                //{
                //    req.Headers.Add(headerKey + ":" + header[headerKey]);
                //}
            }

            HttpWebResponse rsp = null;
            try
            {
                rsp = (HttpWebResponse)req.GetResponse();
                if (HttpStatusCode.OK == rsp.StatusCode)
                {
                    Stream rspStream = rsp.GetResponseStream();     // 响应内容字节流
                    StreamReader sr = new StreamReader(rspStream);
                    string strStream = sr.ReadToEnd();
                    long streamLength = strStream.Length;
                    byte[] response = System.Text.Encoding.UTF8.GetBytes(strStream);
                    rsp.Close();
                    return System.Text.Encoding.UTF8.GetString(response);
                }
                else if (HttpStatusCode.Found == rsp.StatusCode || HttpStatusCode.Moved == rsp.StatusCode)  // 302/301 redirect
                {
                    string reqUrl = rsp.Headers["Location"].ToString();   // 获取重定向URL
                    WebRequest wreq = WebRequest.Create(reqUrl);          // 重定向请求对象
                    WebResponse wrsp = wreq.GetResponse();                // 重定向响应
                    long streamLength = wrsp.ContentLength;               // 重定向响应内容长度
                    Stream rspStream = wrsp.GetResponseStream();          // 响应内容字节流
                    byte[] response = new byte[streamLength];
                    rspStream.Read(response, 0, (int)streamLength);       // 读取响应内容至byte数组
                    rspStream.Close();
                    rsp.Close();
                    return System.Text.Encoding.UTF8.GetString(response);
                }

                rsp.Close();
            }
            catch (WebException e)
            {
                if (rsp != null)
                {
                    rsp.Close();
                }
            }

            return null;
        }
        /// <summary>
        /// HTTP Post请求
        /// </summary>
        /// <param name="uri">HTTP接口Url，不带协议和端口，如/artemis/api/resource/v1/org/advance/orgList</param>
        /// <param name="body">请求参数</param>
        /// <param name="timeout">请求超时时间，单位：秒</param>
        /// <return>请求结果</return>
        public static string HttpPost(string uri, string body, int timeout)
        {
            Dictionary<string, string> header = new Dictionary<string, string>();

            // 初始化请求：组装请求头，设置远程证书自动验证通过
            initRequest(header, uri, body, true);

            // build web request object
            StringBuilder sb = new StringBuilder();
            sb.Append(_isHttps ? "https://" : "http://").Append(_ip).Append(":").Append(_port.ToString()).Append(uri);

            // 创建POST请求
            HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(sb.ToString());
            req.KeepAlive = false;
            req.ProtocolVersion = HttpVersion.Version11;
            req.AllowAutoRedirect = false; // 不允许自动重定向
            req.Method = "POST";
            req.Timeout = timeout * 1000; // 传入是秒，需要转换成毫秒
            req.Accept = header["Accept"];
            req.ContentType = header["Content-Type"];
            req.UserAgent = "PostmanRuntime/7.26.8";

            foreach (string headerKey in header.Keys)
            {
                if (headerKey.Contains("USER_KEY"))
                {
                    req.Headers.Add(headerKey + ":" + header[headerKey]);
                }
                if (headerKey.Contains("USER_SECRET"))
                {
                    req.Headers.Add(headerKey + ":" + header[headerKey]);
                }
                //if (headerKey.Contains("sign"))
                //{
                //    req.Headers.Add(headerKey + ":" + header[headerKey]);
                //}
            }
            byte[] data = Encoding.UTF8.GetBytes(body);

            req.ContentLength = data.Length;

            using (Stream reqStream = req.GetRequestStream())
            {
                reqStream.Write(data, 0, data.Length);

                reqStream.Close();
            }

            HttpWebResponse response = (HttpWebResponse)req.GetResponse();
            Stream stream = response.GetResponseStream();
            Encoding encode = Encoding.UTF8;
            StreamReader reader = new StreamReader(stream, encode);
            string content = reader.ReadToEnd();
            stream.Close();
            reader.Close();
            return content;
        }


        /// <summary>
        /// 远程证书验证
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="cert"></param>
        /// <param name="chain"></param>
        /// <param name="error"></param>
        /// <returns>验证是否通过，始终通过</returns>
        private static bool remoteCertificateValidate(object sender, X509Certificate cert, X509Chain chain,
            SslPolicyErrors error)
        {
            return true;
        }

        private static void initRequest(Dictionary<string, string> header, string url, string body, bool isPost)
        {
            // Accept                
            // string accept = "application/json"; // "*/*";
            string accept = "*/*"; // "*/*";
            header.Add("Accept", accept);

            // ContentType  
            string contentType = "application/json";
            header.Add("Content-Type", contentType);


            //// appId
            //header.Add("USER_KEY", _appkey);
            //// appId
            //header.Add("USER_SECRET", _secret);
            //var timestamp = DateTime.Now.DateToTimeStamp();
            //// build string to sign
            //string signedStr = MD5Helper.Md5EncryptLowerCase(timestamp + _secret);

            //// timestamp
            //header.Add("timestamp", DateTime.Now.DateToTimeStamp());
            //// sign
            //header.Add("sign", signedStr);

            if (_isHttps)
            {
                // set remote certificate Validation auto pass
                ServicePointManager.ServerCertificateValidationCallback =
                    new System.Net.Security.RemoteCertificateValidationCallback(remoteCertificateValidate);
                // FIX：修复不同.Net版对一些SecurityProtocolType枚举支持情况不一致导致编译失败等问题，这里统一使用数值
                // ServicePointManager.SecurityProtocol = (SecurityProtocolType)48 | (SecurityProtocolType)3072 | 
                //                                        (SecurityProtocolType)768 | (SecurityProtocolType)192 ;
                // ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
            }
        }
    }
}