using System;
using System.IO;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Xml;
using Kreta.EESZTInterface.STS;
using Kreta.Resources;

namespace Kreta.EESZTInterface.eFT
{
    public class DoRequest
    {
        public static (XmlDocument soapResponse, byte[] mTOMAttachment) GetSoapSamlResponse(string eftUri, X509Certificate2 sslAuthCert, string soapRequest, SamlAssertion samlAssertion)
        {
            try
            {
                HttpWebRequest request = GetHttpWebRequest(eftUri, sslAuthCert, samlAssertion);
                var (data, hasAttachment) = WriteToHttpStream(request, soapRequest);

                var msResp = new MemoryStream(data);
                StreamReader sr = new StreamReader(msResp);
                var responseString = sr.ReadToEnd();

                if (!hasAttachment)
                {
                    var soapResponse = ThrowIfSoapFault(responseString);
                    return (soapResponse, null);
                }
                else
                {
                    var xmlEleje = responseString.IndexOf("<?xml");
                    var xmlVege = responseString.IndexOf("\r\n--MIME_Boundary");
                    responseString = responseString.Substring(xmlEleje, xmlVege - xmlEleje);
                    var soapResponse = ThrowIfSoapFault(responseString);

                    byte[] boundary1 = Encoding.UTF8.GetBytes("org>" + "\r\n\r\n");
                    byte[] boundary2 = Encoding.UTF8.GetBytes("\r\n--" + "MIME_Boundary" + "--\r\n");
                    var attachment = GetAttachmentData(data, boundary1, boundary2);
                    return (soapResponse, attachment);
                }
            }
            catch (WebException wex)
            {
                string exMessage = wex.Message;

                if (wex.Response != null)
                {
                    using (var responseReader = new StreamReader(wex.Response.GetResponseStream()))
                    {
                        exMessage = responseReader.ReadToEnd();
                        ThrowIfSoapFault(exMessage);
                    }
                }
                throw new Exception(exMessage, wex);
            }
            catch
            {
                throw;
            }
        }

        private static HttpWebRequest GetHttpWebRequest(string stsUri, X509Certificate2 sslAuthCert, SamlAssertion samlAssertion = null)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(stsUri);
            request.Headers.Add("SOAPAction", "");
            request.ContentType = "application/soap+xml;charset=\"utf-8\"";
            request.Accept = "application/soap+xml";
            request.Method = "POST";
            request.ClientCertificates.Add(sslAuthCert);
            return request;
        }

        private static (byte[] data, bool hasAttachment) WriteToHttpStream(HttpWebRequest request, string soapRequest)
        {
            using (Stream stream = request.GetRequestStream())
            {
                MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(soapRequest));
                ms.WriteTo(stream);
            }

            WebResponse response = request.GetResponse();
            MemoryStream msResp = new MemoryStream();

            int read;
            byte[] buffer = new byte[1024];
            while ((read = response.GetResponseStream().Read(buffer, 0, buffer.Length)) > 0)
            {
                msResp.Write(buffer, 0, read);
            }
            return (data: msResp.ToArray(), hasAttachment: response.ContentType.Contains("multipart"));
        }

        private static byte[] GetAttachmentData(byte[] data, byte[] boundary1, byte[] boundary2)
        {
            if (data == null || boundary1 == null || boundary2 == null)
                return null;

            if (boundary1.LongLength > data.LongLength)
                return null;

            long i, j, startIndex;
            bool match;
            int boundary1Pos = 0;

            for (i = 0; i < data.LongLength; i++)
            {
                startIndex = i;
                match = true;
                for (j = 0; j < boundary1.LongLength; j++)
                {
                    if (data[startIndex] != boundary1[j])
                    {
                        match = false;
                        break;
                    }
                    if (startIndex < data.LongLength)
                    {
                        startIndex++;
                    }
                }

                if (match)
                    boundary1Pos = Convert.ToInt32(startIndex - boundary1.LongLength);
            }

            int pos1 = boundary1Pos + boundary1.Length;
            int pos2 = data.Length - boundary2.Length;
            int length = pos2 - pos1;

            try
            {
                byte[] output = new byte[length];
                Array.Copy(data, pos1, output, 0, length);
                return output;
            }
            catch { }
            return null;
        }

        private static XmlDocument ThrowIfSoapFault(string response)
        {
            XmlDocument soapMessage;

            try
            {
                soapMessage = ExtractDocumentFromResponse(response);

                if (soapMessage == null)
                {
                    throw new Exception();
                }
            }
            catch (Exception ex)
            {
                throw new Exception(EESZTInterfaceResource.NemMegfeleloSOAPValaszFormatum, ex);
            }

            XmlElement fault = XmlHelper.GetElement("Fault", Namespaces.soap11Ns, soapMessage.DocumentElement);
            if (fault == null)
            {
                return soapMessage;
            }

            var faultCodeNodes = XmlHelper.GetElement("faultcode", "", fault);
            var faultReasonNodes = XmlHelper.GetElement("faultstring", "", fault);
            var exceptionDetailNodes = XmlHelper.GetElement("detail", "", fault);

            throw new Exception("Hiba! Kód:" + faultCodeNodes.InnerText + " Részletek:" + faultReasonNodes.InnerText,
                  new Exception((exceptionDetailNodes == null) ? "" : exceptionDetailNodes.InnerText));
        }

        private static XmlDocument ExtractDocumentFromResponse(string response)
        {
            var soapResponse = new XmlDocument();
            soapResponse.PreserveWhitespace = true;
            soapResponse.LoadXml(response);
            return soapResponse;
        }

        private bool ValidateServerCertificate(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
        {
            return true;
        }
    }
}