using System;
using System.Collections.Generic;
using System.Text;
using System.Net.Sockets;
using System.Diagnostics;
using System.Threading;
using System.Net;
using MessageLib;
using NetworkLayer.Hashing;
using Ionic.Zlib;
using NetworkLayer;
 
namespace NetworkLayer.Client
{
    public delegate void StringDelegate(object sender, string data);
    public delegate void MessageDelegate(object sender, Msg message);
 
    public class ClientModule
    {
 
        #region Events
 
        public event MessageDelegate OnAckTimedOut;
        public event MessageDelegate OnDataReceived;
        public event StringDelegate OnErrorOccured;
        public event StringDelegate OnConnect;
        public event StringDelegate OnDisconnect;
        public event StringDelegate OnReconnect;
 
        #endregion
 
        #region Variables
 
        // Back buffer.
        private byte[] backBuffer = new byte[StateObject.BufferSize * 10];
        private int backBufferCount = 0;
        private int bbmsgSize = 0;
 
        public List<string> ackNeed = new List<string>();
        public List<Msg> backLog = new List<Msg>();
 
        public static int AckTimeoutCount = 200;
 
        public int ClientID = -1;
        public string ClientName = String.Empty;
        public string ClientType = String.Empty;
        public string ClientIP = String.Empty;
 
        private int msgID = 0;
 
        private bool _isCancel = false;
        public bool IsCancel
        {
            get { return _isCancel; }
            set { _isCancel = value; }
        }
 
        private bool _isReady = false;
        public bool isReady
        {
            get { return isReady; }
        }
 
        // Thread signal
        ManualResetEvent receiveDone = new ManualResetEvent(false);
        public ManualResetEvent clientDone = new ManualResetEvent(false);
        private Socket Client = new Socket(AddressFamily.InterNetwork,
            SocketType.Stream, ProtocolType.Tcp);
 
        //Logging
        Logging.Logger logger = new Logging.Logger("clientModule.log", 5);
 
        #endregion
 
        #region Constructors
 
        public ClientModule() 
        {
            try
            {
                string strHostName = Dns.GetHostName();
                IPHostEntry iphostentry = Dns.GetHostEntry(strHostName);
                IPAddress ipaddress = iphostentry.AddressList[0];
                this.ClientIP = ipaddress.ToString();
 
                Client.SendBufferSize = 512;
                Client.ReceiveBufferSize = 512;
 
            }
            catch (Exception ex)
            {
                logger.Error("ClientModule(), ");
                logger.Error("Error:\r\n" + ex.Message + "\r\nInnerException:\r\n" + ex.InnerException.Message);
            }
        }
 
        #endregion
 
        #region Connect Code
 
        public void Connect(EndPoint remoteEP)
        {
            try
            {
                clientDone.Reset();
 
                Client.BeginConnect(remoteEP,
                    new AsyncCallback(ConnectCallback), Client);
 
                clientDone.WaitOne();
 
            }
            catch (Exception ex)
            {
                logger.Error("Connect(EndPoint), " + remoteEP.ToString());
                logger.Error("Error:\r\n" + ex.Message + "\r\nInnerException:\r\n" + ex.InnerException.Message);
            }
        }
 
        private void ConnectCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket client = (Socket)ar.AsyncState;
 
                // Complete the connection.
                client.EndConnect(ar);
 
                if (OnConnect != null)
                    OnConnect(this, String.Format("Socket connected to {0}", client.RemoteEndPoint.ToString());
 
                StateObject state = new StateObject();
                state.workSocket = client;
 
                client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReceiveCallback), state);
 
                clientDone.WaitOne();
 
            }
            catch (Exception ex)
            {
                logger.Error("ConnectCallback, ");
                logger.Error("Error:\r\n" + ex.Message + "\r\nInnerException:\r\n" + ex.InnerException.Message);
            }
        }
 
        #endregion
 
        #region Receive Code
 
        private void ReceiveCallback(IAsyncResult ar)
        {
            try
            {
                String content = String.Empty;
 
                // Retrieve the state object and the handler socket
                // from the asynchronous state object.
                StateObject state = (StateObject)ar.AsyncState;
                Socket handler = state.workSocket;
 
                // Read data from the client socket.
                int bytesRead = handler.EndReceive(ar);
                //bool gettingMore = false;
                if (bytesRead > 0)
                {
 
                    #region compressed Byte stream Management
 
                    string xmlMessage = String.Empty;
 
                    try
                    {
                        bbmsgSize = Int32.Parse(Encoding.ASCII.GetString(state.buffer, 0, 6));
                    }
                    catch
                    {
                        if (backBufferCount > 6)
                            bbmsgSize = Int32.Parse(Encoding.ASCII.GetString(backBuffer, 0, 6));
                        else
                        {
                            byte[] dummy = new byte[bytesRead + backBufferCount];
                            Buffer.BlockCopy(backBuffer, 0, dummy, 0, backBufferCount);
                            Buffer.BlockCopy(state.buffer, 0, dummy, backBufferCount, bytesRead);
                            bbmsgSize = Int32.Parse(Encoding.ASCII.GetString(dummy, 0, 6));
                            dummy = null;
                        }
                    }
 
                    if (bbmsgSize > (bytesRead + backBufferCount))
                    {
                        // Append data to the backBuffer
                        Buffer.BlockCopy(state.buffer, 0, backBuffer, backBufferCount, bytesRead);
                        backBufferCount += bytesRead;
                    }
                    else if (bbmsgSize == (bytesRead + backBufferCount))
                    {
                        // Append data to the backBuffer
                        Buffer.BlockCopy(state.buffer, 0, backBuffer, backBufferCount, bytesRead);
                        backBufferCount += bytesRead;
                        // deflate the buffer data
                        xmlMessage = deflateBytes(backBuffer);
                        // Clean the backBuffer
                        backBuffer = new byte[StateObject.BufferSize * 10];
                        backBufferCount = 0;
                        bbmsgSize = 0;
                    }
                    else if (bbmsgSize < (bytesRead + backBufferCount))
                    {
                        // Append data to the backBuffer
                        Buffer.BlockCopy(state.buffer, 0, backBuffer, backBufferCount, bytesRead);
                        backBufferCount += bytesRead;
                        // do this untill all messages in backBuffer handled
                        while (true)
                        {
                            int sMsgSize = 0;
                            // make sure sure backBuffer is bigger than 6 bytes
                            if (backBufferCount > 6)
                                sMsgSize = Int32.Parse(Encoding.ASCII.GetString(backBuffer, 0, 6));
                            else
                                break;
                            // make sure backBuffer is bigger than the msg that it wants to retrieve
                            if (backBufferCount < sMsgSize)
                            {
                                bbmsgSize = sMsgSize;
                                break;
                            }
                            // Copy out the msg from the backBuffer
                            byte[] wBuffer = new byte[sMsgSize];
                            Buffer.BlockCopy(backBuffer, 0, wBuffer, 0, sMsgSize);
                            // deflate the buffer data
                            string xml = deflateBytes(wBuffer);
                            //sb.Append(xml);
                            //sb.Append("<delem>");
                            xmlMessage += xml.Trim() + "<delem>";
                            xml = null;
                            // remove the message from the backBuffer
                            // make sure its not the end of the buffer
                            backBufferCount = backBufferCount - sMsgSize;
                            if (backBufferCount == 0)
                            {
                                bbmsgSize = 0;
                                backBuffer = new byte[StateObject.BufferSize * 10];
                                break;
                            }
                            // Copy the remaining backBuffer to the rBuffer (remaindingBuffer)
                            // Then clear the backBuffer and put the remainding buffer back into
                            // the backBuffer for future use.
                            byte[] rBuffer = new byte[backBufferCount];
                            Buffer.BlockCopy(backBuffer, sMsgSize, rBuffer, 0, rBuffer.Length);
                            backBuffer = new byte[StateObject.BufferSize * 10];
                            Buffer.BlockCopy(rBuffer, 0, backBuffer, 0, backBufferCount);
                        }
                    }
                    // clear the reading buffer so that you can use it again
                    state.buffer = new byte[StateObject.BufferSize];
 
                    #endregion
 
                    if (xmlMessage != String.Empty)
                    {
                        string[] msgParts = xmlMessage.Split(new string[] { "<delem>" }, StringSplitOptions.RemoveEmptyEntries);
                        for (int i = 0; i < msgParts.Length; i++)
                        {
                            Msg reader = new Msg();
                            Msg msg = reader.DeSerialize(msgParts[i]);
                            MessageHandler(msg);
                        }
 
                    }
 
                    content = string.Empty;
                    receiveDone.Set();
                }
                if (handler != null && handler.Connected == true)
                {
                    handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                        new AsyncCallback(ReceiveCallback), state);
                    receiveDone.WaitOne();
                }
            }
            catch (Exception ex)
            {
                logger.Error("ReceiveCallback, ");
                logger.Error("Error:\r\n" + ex.Message + "\r\nInnerException:\r\n" + ex.InnerException.Message);
            }
        }
 
        private string deflateBytes(byte[] wBuffer)
        {
            string xmlMessage = String.Empty;
 
            try
            {
                int msgSize = Int32.Parse(Encoding.ASCII.GetString(wBuffer, 0, 6));
                int crcSize = Int32.Parse(Encoding.ASCII.GetString(wBuffer, 6, 2));
 
                byte[] crcByte = new byte[crcSize];
                Buffer.BlockCopy(wBuffer, 8, crcByte, 0, crcSize);
                byte[] workBuffer = new byte[msgSize - (8 + crcSize)];
                Buffer.BlockCopy(wBuffer, 8 + crcSize, workBuffer, 0, msgSize - (8 + crcSize));
 
                Crc32 crc = new Crc32();
                byte[] checkSum = crc.ComputeHash(workBuffer);
 
                ZlibCodec compressor = new ZlibCodec(CompressionMode.Decompress);
                //int rc = compressor.InitializeDeflate(CompressionLevel.Level9);
 
                byte[] deflatedBuffer = new byte[51200];
 
                compressor.InputBuffer = workBuffer;
                compressor.NextIn = 0;
 
                compressor.OutputBuffer = deflatedBuffer;
                compressor.NextOut = 0;
 
                compressor.AvailableBytesOut = deflatedBuffer.Length;
                compressor.AvailableBytesIn = workBuffer.Length;
                int rc1 = compressor.Inflate(FlushType.None);
                int rc2 = compressor.Inflate(FlushType.Finish);
                int rc3 = compressor.EndInflate();
 
                xmlMessage = Encoding.ASCII.GetString(deflatedBuffer);
 
                xmlMessage = (xmlMessage.Split(new string[] { "</Msg>" }, StringSplitOptions.RemoveEmptyEntries)[0] + "</Msg>");
 
            }
            catch (Exception ex)
            {
                logger.Error("deflateBytes, wBuffer:" + Encoding.ASCII.GetString(wBuffer));
                logger.Error("Error:\r\n" + ex.Message + "\r\nInnerException:\r\n" + ex.InnerException.Message);
            }
            return xmlMessage;
        }
 
        public void MessageHandler(Msg msg)
        {
            try
            {
                if (msg.Header != null)
                {
                    switch (msg.Header.msgType)
                    {
                        case "handShake":
                            handShake handshake = (handShake)msg.Body.Messages[0];
                            handshake.ClientName = this.ClientName;
                            handshake.ClientType = this.ClientType;
                            handshake.ClientIP = this.ClientIP;
                            this.ClientID = handshake.ClientID;
 
                            Header head = new Header();
                            head.fromSystem = this.ClientIP;
                            head.msgType = "handShake";
                            head.toSystem = msg.Header.fromSystem;
                            head.msgID = (msgID++).ToString();
 
                            Body body = new Body();
                            body.Add(handshake);
 
                            Msg sendMessage = new Msg(head, body);
 
                            _isReady = true;
                            Send(sendMessage);
 
                            break;
                        default:
                            OnDataReceived(this, msg);
 
                            break;
                    }
                    // Signal that the connection has been made.
                    clientDone.Set();
                }
                else if (msg.ACK != null)
                {
                    switch (msg.ACK.msgType)
                    {
                        case "handShake":
                            OnDataReceived(this, msg);
 
                            break;
                        default:
                            OnDataReceived(this, msg);
 
                            break;
                    }
                    int index = 0;
                    foreach (string id in ackNeed)
                    {
                        if (id == msg.ACK.msgID)
                        {
                            backLog.RemoveAt(index);
                            ackNeed.Remove(id);
                            break;
                        }
                        index++;
                    }
                    clientDone.Set();
                }
 
            }
            catch (Exception ex)
            {
                logger.Error("MessageHandler, ");
                logger.Error("Error:\r\n" + ex.Message + "\r\nInnerException:\r\n" + ex.InnerException.Message);
            }
        }
 
        #endregion
 
        #region Send Code
 
        public void Send(Msg message)
        {
            try
            {
                if (_isReady)
                {
                    clientDone.Reset();
                    //Thread.Sleep(100);
                    if (message.Header.msgID == null)
                        message.Header.msgID = (this.msgID++).ToString();
 
 
                    lock (ackNeed)
                    {
                        ackNeed.Add(message.Header.msgID);
                        backLog.Add(message);
                    }
 
                    string xmlMessage = message.Serialize();// + Convert.ToChar(3);
 
                    #region Converting to byte[] compressing, hashing data and setting up Header
 
                    // Convert the string data to byte data using ASCII encoding.
                    // And compress the Bytes
 
                    byte[] byteData = Encoding.ASCII.GetBytes(xmlMessage);
                    byte[] decompByteData = new byte[xmlMessage.Length];
                    byte[] compressedByteData = new byte[xmlMessage.Length];
 
                    ZlibCodec compressor = new ZlibCodec();
                    int rc = compressor.InitializeDeflate(CompressionLevel.Level9);
 
                    compressor.InputBuffer = Encoding.ASCII.GetBytes(xmlMessage);
                    compressor.NextIn = 0;
 
                    compressor.OutputBuffer = compressedByteData;
                    compressor.NextOut = 0;
 
                    compressor.AvailableBytesOut = xmlMessage.Length;
                    compressor.AvailableBytesIn = xmlMessage.Length;
                    int rc1 = compressor.Deflate(FlushType.None);
                    int rc2 = compressor.Deflate(FlushType.Finish);
                    int rc3 = compressor.EndDeflate();
 
                    byte[] finalByteData = new byte[((int)compressor.TotalBytesOut)];
                    Buffer.BlockCopy(compressedByteData, 0, finalByteData, 0, (int)compressor.TotalBytesOut);
 
                    Crc32 crc = new Crc32();
                    byte[] computedHash = crc.ComputeHash(finalByteData);
                    byte[] header = new byte[8 + computedHash.Length];
 
                    int headLen = header.Length;
                    int bodyLen = (int)compressor.TotalBytesOut;
                    int totalLen = headLen + bodyLen;
 
                    byte[] lencomputedHash = new byte[2];
                    lencomputedHash = Encoding.ASCII.GetBytes(computedHash.Length.ToString());
 
                    byte[] lenBytes = new byte[6];
                    lenBytes = Encoding.ASCII.GetBytes(totalLen.ToString());
 
                    Buffer.BlockCopy(lenBytes, 0, header, 0, lenBytes.Length);
                    Buffer.BlockCopy(lencomputedHash, 0, header, 6, lencomputedHash.Length);
                    Buffer.BlockCopy(computedHash, 0, header, 8, computedHash.Length);
 
                    byte[] hashedFinal = new byte[((int)compressor.TotalBytesOut) + header.Length];
                    Buffer.BlockCopy(header, 0, hashedFinal, 0, header.Length);
                    Buffer.BlockCopy(finalByteData, 0, hashedFinal, header.Length, finalByteData.Length);
 
                    // Testing multi messages
 
                    //byte[] dummy3 = new byte[hashedFinal.Length * 3];
                    //for (int i = 0; i < 3; i++)
                    //{
                    //    Buffer.BlockCopy(hashedFinal, 0, dummy3, i * hashedFinal.Length, hashedFinal.Length);
                    //}
 
                    #endregion
 
                    // Begin sending the data to the remote device.
                    Client.BeginSend(hashedFinal, 0, hashedFinal.Length, 0,
                            new AsyncCallback(SendCallback), Client);
 
                    clientDone.WaitOne();
 
                    AckTimeOutObject ackTO = new AckTimeOutObject();
                    ackTO.timeout = AckTimeoutCount;
                    ackTO.msgID = message.Header.msgID;
 
                    Thread ackThread = new Thread(AckTimeout);
                    ackThread.IsBackground = true;
                    ackThread.Start(ackTO);
                }
 
            }
            catch (Exception ex)
            {
                logger.Error("Send, Message:\r\n" + message.Serialize());
                logger.Error("Error:\r\n" + ex.Message + "\r\nInnerException:\r\n" + ex.InnerException.Message);
 
            }
        }
 
        public void SendACK(string msgType, string msgAction, string msgID, string toSystem, string msgProcessedBy)
        {
            try
            {
                ACK ack = new ACK();
                ack.fromSystem = this.ClientIP;
                ack.toSystem = toSystem;
                ack.msgType = msgType;
                ack.msgID = msgID;
                ack.msgAction = msgAction;
                ack.msgProcessedBy = msgProcessedBy;
                Msg message = new Msg(ack);
                Send(message);
 
            }
            catch (Exception ex)
            {
                logger.Error("SendACK, ");
                logger.Error("Error:\r\n" + ex.Message + "\r\nInnerException:\r\n" + ex.InnerException.Message);
            }
        }
 
        public void AckTimeout(object acktimeout)
        {
            AckTimeOutObject ackTO = (AckTimeOutObject)acktimeout;
            Thread.Sleep(ackTO.timeout);
            bool found = false;
            int index = 0;
 
            try
            {
                lock (ackNeed)
                {
                    foreach (string id in ackNeed)
                    {
                        if (id == ackTO.msgID)
                        {
                            found = true;
                            ackNeed.Remove(id);
                            break;
                        }
                        index++;
                    }
                    if (found)
                    {
                        if (OnAckTimedOut != null)
                        {
                            OnAckTimedOut(this, backLog[index]);
                            backLog.RemoveAt(index);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                string exMsg = ex.Message;
                if (exMsg.Contains("Collection was modified;"))
                {
                    ackTO.timeout = 10;
                    Thread ackThread = new Thread(AckTimeout);
                    ackThread.IsBackground = true;
                    ackThread.Start(ackTO);
                }
            }
        }
 
        public void SendCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket handler = (Socket)ar.AsyncState;
 
                // Complete sending the data to the remote device.
                int bytesSent = handler.EndSend(ar);
                //Console.WriteLine("Sent {0} bytes to server.", bytesSent);
 
                clientDone.Set();
 
            }
            catch (Exception ex)
            {
                logger.Error("SendCallback, ");
                logger.Error("Error:\r\n" + ex.Message + "\r\nInnerException:\r\n" + ex.InnerException.Message);
            }
        }
 
        #endregion
 
        #region Keep Alive
 
        private void startKeepAlive()
        {
            Client.Poll(100, SelectMode.SelectError);
        }
 
        #endregion
 
        public void Shutdown()
        {
            try
            {
                Client.Shutdown(SocketShutdown.Both);
                Client.Close();
 
            }
            catch (Exception ex)
            {
                logger.Error("Shutdown(), ");
                logger.Error("Error:\r\n" + ex.Message + "\r\nInnerException:\r\n" + ex.InnerException.Message);
            }
        }
 
    }
}