using Lskj.Web.Core.Util;
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Web;

namespace Lskj.Util
{
    public static class HttpHelper
    {
        private const int RequestTimeout = 120000;
        private const int Tls12 = 3072;
        private const int UploadChunkMaxAttempts = 3;

        public enum Encode
        {
            Default = 0,
            UTF8 = 1
        }
        private static string ContentType = string.Empty;// "application/x-www-form-urlencoded";
        private static string Accept = string.Empty;//"text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5";
        private static string UserAgent = string.Empty;//"Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14";
        private static Encode EncodeMode = Encode.Default;
        public static void Setting(string contentType, string accept, string userAgent, Encode encode = Encode.Default)
        {
            ContentType = contentType;
            Accept = accept;
            UserAgent = userAgent;
            EncodeMode = encode;
        }

        private static void ConfigureTransport()
        {
            try
            {
                ServicePointManager.SecurityProtocol |= (SecurityProtocolType)Tls12;
                ServicePointManager.Expect100Continue = false;
                if (ServicePointManager.DefaultConnectionLimit < 20)
                {
                    ServicePointManager.DefaultConnectionLimit = 20;
                }
            }
            catch
            {
            }
        }

        private static void ConfigureRequest(HttpWebRequest request)
        {
            request.Timeout = RequestTimeout;
            request.ReadWriteTimeout = RequestTimeout;
            request.KeepAlive = false;
            request.ServicePoint.Expect100Continue = false;
            request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
        }

        private static string BuildExceptionMessage(Exception ex)
        {
            StringBuilder builder = new StringBuilder();
            builder.Append(ex.Message);
            if (ex.InnerException != null)
            {
                builder.AppendFormat("; Inner={0}", ex.InnerException.Message);
            }
            return builder.ToString();
        }

        private static string BuildWebExceptionMessage(WebException ex)
        {
            StringBuilder builder = new StringBuilder();
            builder.Append(BuildExceptionMessage(ex));
            builder.AppendFormat("; Status={0}", ex.Status);

            HttpWebResponse response = ex.Response as HttpWebResponse;
            if (response != null)
            {
                builder.AppendFormat("; HttpStatus={0} {1}", (int)response.StatusCode, response.StatusDescription);
                try
                {
                    Stream responseStream = response.GetResponseStream();
                    if (responseStream != null)
                    {
                        using (StreamReader streamReader = new StreamReader(responseStream, Encoding.UTF8))
                        {
                            string responseText = streamReader.ReadToEnd();
                            if (!string.IsNullOrEmpty(responseText))
                            {
                                builder.AppendFormat("; Response={0}", responseText);
                            }
                        }
                    }
                }
                catch
                {
                }
            }

            return builder.ToString();
        }

        private static bool IsTransientUploadException(WebException ex)
        {
            if (ex == null)
            {
                return false;
            }

            switch (ex.Status)
            {
                case WebExceptionStatus.ConnectFailure:
                case WebExceptionStatus.ConnectionClosed:
                case WebExceptionStatus.KeepAliveFailure:
                case WebExceptionStatus.PipelineFailure:
                case WebExceptionStatus.ReceiveFailure:
                case WebExceptionStatus.SendFailure:
                case WebExceptionStatus.Timeout:
                    return true;
                default:
                    return false;
            }
        }

        /// <summary>
        /// post数据到指定的网址，获取cookie数据，和返回页
        /// </summary>
        public static HttpWebResponse Post(string url, string postData, Dictionary<string, string> pmsDic, Dictionary<string, string> headerDic, out string result)
        {
            HttpWebResponse httpWebResponse = null;
            try
            {
                HttpWebRequest httpWebRequest;
                ConfigureTransport();
                httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(url);
                ConfigureRequest(httpWebRequest);

                httpWebRequest.ContentType = ContentType;
                httpWebRequest.Accept = Accept;
                httpWebRequest.UserAgent = UserAgent;
                httpWebRequest.Method = "POST";
                byte[] byteRequest = null;
                if (headerDic != null)
                {
                    foreach (var item in headerDic)
                    {
                        if (item.Key.Equals("Content-Type"))
                        {
                            httpWebRequest.ContentType = item.Value;
                        }
                        else
                        {
                            httpWebRequest.Headers.Add(item.Key, item.Value);
                        }
                    }
                }
                if (!string.IsNullOrEmpty(postData))
                {
                    switch (EncodeMode)
                    {
                        case Encode.Default:
                            byteRequest = Encoding.Default.GetBytes(postData);
                            break;
                        case Encode.UTF8:
                            byteRequest = Encoding.UTF8.GetBytes(postData);
                            break;
                    }
                    httpWebRequest.ContentLength = byteRequest.Length;
                }
                else if (pmsDic != null)
                {
                    StringBuilder builder = new StringBuilder();
                    int i = 0;
                    foreach (var item in pmsDic)
                    {
                        if (i > 0)
                            builder.Append("&");
                        builder.AppendFormat("{0}={1}", item.Key, item.Value);
                        i++;
                    }
                    switch (EncodeMode)
                    {
                        case Encode.Default:
                            byteRequest = Encoding.Default.GetBytes(builder.ToString());
                            break;
                        case Encode.UTF8:
                            byteRequest = Encoding.UTF8.GetBytes(builder.ToString());
                            break;
                    }
                    httpWebRequest.ContentLength = byteRequest.Length;
                }
                Stream stream = httpWebRequest.GetRequestStream();
                stream.Write(byteRequest, 0, byteRequest.Length);
                stream.Close();
                httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
                Stream responseStream = httpWebResponse.GetResponseStream();
                StreamReader streamReader = new StreamReader(responseStream, Encoding.UTF8);
                result = streamReader.ReadToEnd();
                streamReader.Close();
                responseStream.Close();

                return httpWebResponse;
            }
            catch (WebException ex)
            {
                Console.WriteLine(ex.ToString());
                result = BuildWebExceptionMessage(ex);
                return httpWebResponse;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                result = BuildExceptionMessage(ex);
                return httpWebResponse;
            }
        }
        /// <summary>
        /// Get到指定的网址，获取cookie数据，和返回页
        /// </summary>
        public static HttpWebResponse Get(string url, string postData, Dictionary<string, string> pmsDic, Dictionary<string, string> headerDic, out string result)
        {
            HttpWebResponse httpWebResponse = null;
            try
            {
                StringBuilder builder = new StringBuilder(url);
                if (pmsDic != null && pmsDic.Count > 0)
                {
                    builder.Append("?");
                    int i = 0;
                    foreach (var item in pmsDic)
                    {
                        if (i > 0)
                            builder.Append("&");
                        builder.AppendFormat("{0}={1}", item.Key, item.Value);
                        i++;
                    }
                }
                HttpWebRequest httpWebRequest;
                ConfigureTransport();
                httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(builder.ToString());
                ConfigureRequest(httpWebRequest);
                httpWebRequest.ContentType = ContentType;
                //httpWebRequest.Referer = url;
                httpWebRequest.Accept = Accept;
                httpWebRequest.UserAgent = UserAgent;
                httpWebRequest.Method = "GET";
                if (headerDic != null)
                {
                    foreach (var item in headerDic)
                    {
                        if (item.Key.Equals("Content-Type"))
                        {
                            httpWebRequest.ContentType = item.Value;
                        }
                        else
                        {
                            httpWebRequest.Headers.Add(item.Key, item.Value);
                        }
                    }
                }
                httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
                Stream responseStream = httpWebResponse.GetResponseStream();
                StreamReader streamReader = new StreamReader(responseStream, Encoding.UTF8);
                result = streamReader.ReadToEnd();
                streamReader.Close();
                responseStream.Close();

                return httpWebResponse;
            }
            catch (WebException ex)
            {
                Console.WriteLine(ex.ToString());
                result = BuildWebExceptionMessage(ex);
                return httpWebResponse;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                result = BuildExceptionMessage(ex);
                return httpWebResponse;
            }
        }
        /// <summary>
        /// 分片上传
        /// </summary>
        /// <param name="url"></param>
        /// <param name="fileBytes"></param>
        /// <param name="fileName"></param>
        /// <param name="headerDic"></param>
        /// <param name="result"></param>
        /// <returns></returns>
        public static HttpWebResponse PostFileChunk(string url, byte[] fileBytes, string fileName, Dictionary<string, string> headerDic, out string result)
        {
            result = "";
            for (int attempt = 1; attempt <= UploadChunkMaxAttempts; attempt++)
            {
                HttpWebRequest httpWebRequest = null;
                HttpWebResponse httpWebResponse = null;
                try
                {
                    string boundary = "----WebKitFormBoundary" + DateTime.Now.Ticks.ToString("x");

                    ConfigureTransport();
                    httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(url);
                    ConfigureRequest(httpWebRequest);
                    // 客户网络中的代理/防火墙可能在复用连接时主动断开。
                    // 分片请求使用独立连接，避免 ERP 进程内其他 HTTP 请求
                    // 留下的连接状态影响当前上传。
                    httpWebRequest.KeepAlive = false;
                    httpWebRequest.ConnectionGroupName = "LserpUpload-"
                        + Guid.NewGuid().ToString("N");
                    httpWebRequest.ProtocolVersion = HttpVersion.Version11;
                    httpWebRequest.Method = "POST";
                    httpWebRequest.Accept = Accept;
                    httpWebRequest.UserAgent = string.IsNullOrEmpty(UserAgent)
                        ? "Lserp-Desktop/6.0"
                        : UserAgent;
                    httpWebRequest.ContentType = "multipart/form-data; boundary=" + boundary;

                    if (headerDic != null)
                    {
                        foreach (var item in headerDic)
                        {
                            if (!item.Key.Equals("Content-Type"))
                            {
                                httpWebRequest.Headers.Add(item.Key, item.Value);
                            }
                        }
                    }

                    string header =
                        "--" + boundary + "\r\n" +
                        "Content-Disposition: form-data; name=\"file\"; filename=\"" + fileName + "\"\r\n" +
                        "Content-Type: application/octet-stream\r\n\r\n";

                    string footer = "\r\n--" + boundary + "--\r\n";
                    byte[] headerBytes = Encoding.UTF8.GetBytes(header);
                    byte[] footerBytes = Encoding.UTF8.GetBytes(footer);

                    httpWebRequest.ContentLength = headerBytes.Length + fileBytes.Length + footerBytes.Length;

                    using (Stream stream = httpWebRequest.GetRequestStream())
                    {
                        stream.Write(headerBytes, 0, headerBytes.Length);
                        stream.Write(fileBytes, 0, fileBytes.Length);
                        stream.Write(footerBytes, 0, footerBytes.Length);
                    }

                    httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();

                    using (Stream responseStream = httpWebResponse.GetResponseStream())
                    using (StreamReader streamReader = new StreamReader(responseStream, Encoding.UTF8))
                    {
                        result = streamReader.ReadToEnd();
                    }

                    return httpWebResponse;
                }
                catch (WebException ex)
                {
                    Console.WriteLine(ex.ToString());
                    string exceptionMessage = BuildWebExceptionMessage(ex);
                    httpWebResponse?.Close();
                    ex.Response?.Close();
                    httpWebRequest?.Abort();

                    if (attempt < UploadChunkMaxAttempts && IsTransientUploadException(ex))
                    {
                        System.Threading.Thread.Sleep(attempt * 1000);
                        continue;
                    }

                    result = string.Format("{0}; Attempts={1}", exceptionMessage, attempt);
                    return null;
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.ToString());
                    httpWebResponse?.Close();
                    httpWebRequest?.Abort();
                    result = BuildExceptionMessage(ex);
                    return null;
                }
            }

            return null;
        }

        /// <summary>
        /// url转换
        /// </summary>
        /// <param name="url"></param>
        /// <returns></returns>
        public static string ToEnUrl(string url)
        {
            string[] urlParams = url.Split('?');
            string enKey = "encrypt", enVal = "";
            bool hasEn = false;
            if (urlParams.Length > 1)
            {
                string[] queryParams = urlParams[1].Split('&');
                List<string> qpLS = new List<string>();
                Hashtable pms = new Hashtable();
                hasEn = queryParams.Any(str => str.Trim().StartsWith(enKey, StringComparison.OrdinalIgnoreCase));
                foreach (string q in queryParams)
                {
                    string[] eqParams = q.Split('=');
                    if (eqParams.Length > 1)
                    {
                        if (hasEn && eqParams[0].ToLower() == enKey)
                        {
                            enVal = eqParams[1];
                            continue;
                        }
                        if (hasEn || eqParams[0].ToLower() == "username" || eqParams[0].ToLower() == "password")
                        {
                            pms.Add(eqParams[0], eqParams[1]);
                        }
                        else
                        {
                            qpLS.Add(string.Format("{0}={1}", eqParams[0], HttpUtility.UrlEncode(eqParams[1])));
                        }
                    }
                    else
                    {
                    }
                }
                if (pms.Count > 0)
                {
                    DateTime dateTime = DateTime.Now.AddDays(1);
                    DateTime epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
                    long timestamp = (dateTime.Ticks - epoch.Ticks) / TimeSpan.TicksPerSecond;
                    pms.Add("exp", timestamp);
                }
                return $"{urlParams[0]}?pms={HttpUtility.UrlEncode(hasEn ? Lskj.Web.Core.Util.safety.AESUtil.Encrypt(JSON.Encode(pms), enVal) : Lskj.Web.Core.Util.safety.AESUtil.MobileEncrypt(JSON.Encode(pms)))}&{qpLS.SJoin("&")}";
            }
            return url;
        }
    }
}