using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Xml;
using System.Security.Cryptography.X509Certificates;
using System.Security;

namespace Intel.Management.Wsman
{
    class ClientRequest : IDisposable
    {
        private readonly HttpTransport _transport; //message transport
             
        public ClientRequest(Uri address, AddressFamily addressType)
        {
            _transport = string.Compare(address.Scheme, "https", true) == 0
                ? new TlsTransport(addressType, address)
                : new PlainTextTransport(addressType, address);
        }

        public Uri Address => _transport.Address;

        /// <summary>
        /// Sends the XML to Amt and returns the response XML
        /// </summary>
        /// <param name="reqDoc">The XML to send</param>
        /// <param name="soapCmd">Optional Soap Action to send</param>
        /// <returns></returns>
        public ServerResponse Send(XmlDocument reqDoc, string soapCmd)
        {
            ServerResponse result = null;
            string proxyToken = null;
            string authToken = null;
   
             // make sure there is authorization
            GetAuthorization();
            int retry = _transport.Authorization.MaxAttempts;

           // _transport.Proxy = new HttpProxy("http://localhost:8080","randy","P@ssw0rd");
 
            while (retry >0)
            {
                if (authToken == null)
                {
                    switch (_transport.Authorization.State)
                    {
                        case HandshakeState.CredentialsAquired:
                            // get the initial token (this message will be sent with it)
                            authToken = _transport.Authorization.GetInitialToken();
                            break;
                        case HandshakeState.ResponseNeeded:
                            // get the next token (this message will be sent with it)
                            authToken = _transport.Authorization.GetNextToken();
                            break;
                        case HandshakeState.Failed:
                            break; // result may null
                    }
                }
                
                int contentLength = -1;
                if (reqDoc != null)
                {
                    byte[] data = Encoding.UTF8.GetBytes(reqDoc.OuterXml);
                    contentLength = data.Length;
                }

                using (StringWriter writer = new StringWriter())
                {
                    writer.Write("POST ");
                    writer.Write(_transport.GetRequestUri());
                    writer.Write(" HTTP/1.1");
                    writer.WriteLine();
                    writer.Write("Host: ");
                    writer.Write(_transport.Address.Authority);
                    writer.WriteLine();
                    writer.Write("User-Agent: AmtClient/1.0");
                    writer.WriteLine();
                    writer.Write("Content-Type: text/xml; charset=utf-8");
                    writer.WriteLine();
                    writer.Write("Content-Length: ");
                    writer.Write(contentLength.ToString());
                    writer.WriteLine();
                    writer.Write("Connection: keep-alive");
                    writer.WriteLine();

                    if (authToken != null && !authToken.Equals(string.Empty))
                    {
                        writer.Write("Authorization: ");
                        writer.Write(authToken);
                        writer.WriteLine();
                    }

                    if (proxyToken != null)
                    {
                        writer.Write("Proxy-Authorization: ");
                        writer.Write(proxyToken);
                        writer.WriteLine();
                    }

                    // add optional SoapAction
                    if (soapCmd != null)
                    {
                        writer.Write("SOAPAction: ");
                        if (!soapCmd.StartsWith("\""))
                            writer.Write("\"");
                        writer.Write(soapCmd);
                        if (!soapCmd.StartsWith("\""))
                            writer.Write("\"");
                        writer.WriteLine();
                    }

                    writer.WriteLine();
                    
                    _transport.InitializeRequest();

                    //send headers first
                    _transport.SendMessageHeaders(writer.ToString());
                }

                //next send body (if any)
                if (reqDoc != null)
                    _transport.SendMessageBody(reqDoc.OuterXml);
                result=_transport.GetResponse("POST");
                proxyToken = null;

                if (result.StatusCode == 401 || result.StatusCode==407 )
                {

                    if (result.StatusCode == 401)
                    {
                        if (_transport.Authorization.State != HandshakeState.ResponseNeeded)
                            retry = 0;
                        retry--;
                        if (retry > 0)
                            _transport.Authorization.SetReturnToken(result.Challange);
                    }

                    // if we have a proxy challange then get the proxy authorization
                    if (!string.IsNullOrEmpty(result.ProxyChallange))
                    {
                        proxyToken = _transport.GetProxyAuthorization("POST", _transport.Address.LocalPath, result);
                        retry = 3;
                    }
                    else  
                    {
                        authToken = null; // only keep the authToken if we have a proxy challenge
                    }
                }
                else 
                {
                    retry = 0;
                    authToken = null;
                 
                }
            }

            return result;
        }

        /// <summary>
        /// Sends the XML to Amt and returns the response XML
        /// </summary>
        /// <param name="reqDoc">The XML to send</param>
        /// <returns></returns>
        public ServerResponse Send(XmlDocument reqDoc)
        {
            return Send(reqDoc, null);
        }

        public ISecurityHandshake GetAuthorization()
        {
            if (_transport.Authorization == null)
                _transport.Authorization = new AnonymousAuthorization();
            return _transport.Authorization;
        }

        public void SetProxy(HttpProxy proxy)
        {
            _transport.Proxy = proxy;
        }

        public void SetWindowsAuthorization(string user, string domain, SecureString password, string spn)
        {
            if (string.IsNullOrEmpty(spn))
                spn = "HTTP/" + Address?.Authority.ToUpper();
            _transport.Authorization = new WindowsAuthorization(user, domain, password, spn);
        }

        public void SetDigestAuthorization(string user, SecureString password)
        {
            _transport.Authorization = new DigestAuthorization(user, password, _transport.Address.LocalPath, "POST");
        }

        public void SetAnonymousAuthorization()
        {
            _transport.Authorization = new AnonymousAuthorization();
        }

        public void SetCertificate(X509Certificate2 cert)
        {
            _transport.SetCredentials(cert);
        }

        public void SetCertificateOptions(bool verifyCa,bool verifyCN, bool sendRoot)
        {
            _transport.SetCertificateValidationOptions(verifyCa, verifyCN, sendRoot);
        }
        
        #region IDisposable Members

        private bool _disposed = false;

        protected virtual void Dispose(bool disposing)
        {
            if (_disposed)
                return;
            if (disposing)
            {
                _transport?.Dispose();
            }
            _disposed = true;
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        #endregion
    }
}//end namespace