C# Zevera hoster API functionality

        public static String doLinkZevera1(String strlink, String strUserPass)
        {
            String link = strlink;

            String[] strSplittedUserPass = strUserPass.Split(new char[] { ':' });
            String strUser = strSplittedUserPass[0]; String strPass = strSplittedUserPass[1];

            String strHTTPPesponseLine = String.Concat<String>(new List<String>() { "login=", HttpUtility.UrlEncode(strUser), "&pass=", HttpUtility.UrlEncode(strPass) });

            // Lambda function expression
            Func<String, String, String, String, System.IO.Stream> func_GetIOStream = delegate (String strURL, String str_HTTPPesponseLine, String RequestMethod, String strDelimiter)
            {
                var Resp = PostHTTPRequestToServer(strURL, str_HTTPPesponseLine, RequestMethod, strDelimiter);
                return (Resp != null) ? Resp.GetResponseStream() : System.IO.Stream.Null;
            };

            System.IO.StreamReader streamReader = new System.IO.StreamReader(func_GetIOStream.Invoke(StrZeveraLinkerLoginRequestHeader, strHTTPPesponseLine, System.Net.WebRequestMethods.Http.Post, "&"));

            String strReadedFromStream = streamReader.ReadToEnd();
            if (ValidateJSON(strReadedFromStream)) return String.Empty;

            if ("No trafic".Equals(strReadedFromStream) || String.IsNullOrEmpty(strReadedFromStream) || strReadedFromStream.Trim().Length == 0) return String.Empty;
            strReadedFromStream = strReadedFromStream.Trim();
            if ("Login Error".ToLower().Equals(strReadedFromStream.ToLower())) return String.Empty;

            String strEndSubscriptionDate = new Regex("EndSubscriptionDate:(.*?),", RegexOptions.Compiled | RegexOptions.IgnoreCase).Matches(strReadedFromStream)[0].Value.Replace("EndSubscriptionDate:", String.Empty).Replace(",", String.Empty);
            DateTime dtEndSubscriptionDate = DateTime.ParseExact(strEndSubscriptionDate, "yyyy/M/d HH:mm:ss", CultureInfo.InvariantCulture);

            String strAvailableTodayTraffic = new Regex("AvailableTodayTraffic:(.*?),", RegexOptions.Compiled | RegexOptions.IgnoreCase).Matches(strReadedFromStream)[0].Value.Replace("AvailableTodayTraffic:", "").Replace(",", "");
            int iAvailableTodayTraffic = (int)(Convert.ToInt64(strAvailableTodayTraffic)); // Gigabytes

            if (iAvailableTodayTraffic == 0 || DateTime.Compare(dtEndSubscriptionDate, DateTime.Now) < 0) { return strlink; }


            strHTTPPesponseLine = String.Concat<String>(new List<String>() { "login=", HttpUtility.UrlEncode(strUser), "&pass=", HttpUtility.UrlEncode(strPass), "&olink=" + HttpUtility.UrlEncode(link) });
            streamReader = new System.IO.StreamReader(func_GetIOStream.Invoke(StrZeveraLinkerGenerateDownloadRequestHeader, strHTTPPesponseLine, System.Net.WebRequestMethods.Http.Post, "&"));

            strReadedFromStream = streamReader.ReadToEnd();
            if (ValidateJSON(strReadedFromStream)) return String.Empty;

            if (!strReadedFromStream.Contains("File Added Successfully!") || String.IsNullOrEmpty(strReadedFromStream) || strReadedFromStream.Trim().Length == 0) return String.Empty;

            String strFileID = new Regex("FileID:(.*?),", RegexOptions.Compiled | RegexOptions.IgnoreCase).Matches(strReadedFromStream)[0].Value.Replace("FileID:",String.Empty).Replace(",", String.Empty);

            strHTTPPesponseLine = String.Concat<String>(new List<String>() { "login=", HttpUtility.UrlEncode(strUser), "&pass=", HttpUtility.UrlEncode(strPass), "&FileID=" + HttpUtility.UrlEncode(strFileID) });
            streamReader = new System.IO.StreamReader(func_GetIOStream.Invoke(StrZeveraLinkerDownloadRequestHeader, strHTTPPesponseLine, System.Net.WebRequestMethods.Http.Post, "&"));

            strReadedFromStream = streamReader.ReadToEnd();
            if (ValidateJSON(strReadedFromStream)) return String.Empty;

            return strlink;
        }