//*******************************************************************************
//* Copyright (c) 2008-2014 Synchrotron SOLEIL
//* All rights reserved. This program and the accompanying materials
//* are made available under the terms of the GNU Lesser Public License v3
//* which accompanies this distribution, and is available at
//* http://www.gnu.org/licenses/lgpl.html
//******************************************************************************
//******************************************************************************************
//
//
//    september 13, 2004 :  Source file for the communication in socket mode
//
//                with a Lecroy scope (avaiable for all models)
//
//    author : X.Elattaoui
//
//    SocketLecroy.cpp: implementation of the SocketLecroy class.
//
//******************************************************************************************

static int  hSocket;
static int  sTimeout = 15;
static char sCurrentAddress[256];
static int  sConnectedFlag = false;
const int CMD_BUF_LEN = 8192;
static char sCommandBuffer[CMD_BUF_LEN];

//- INCLUDE
#include "SocketLecroy.h"

//- init of the static instance
SocketLecroy* SocketLecroy::SL_instance = 0;  //- ptr on the SocketLecroy instance

SocketLecroy* SocketLecroy::get_instance()
{
  if( !SL_instance )
    SL_instance = new SocketLecroy();

  return SL_instance;
}

void SocketLecroy::delete_instance(SocketLecroy* SL_instance)
{
  if(SL_instance)
  {
    delete SL_instance ;
    SL_instance = 0;
  }
}

//- CTOR
SocketLecroy::SocketLecroy()
{
  sConnectedFlag = false;
}

//- DTOR
SocketLecroy::~SocketLecroy()
{
  TCP_Disconnect();
}

//- Build the connection
void SocketLecroy::TCP_Connect(char *ip_address) throw (lecroy::SocketException)
{
  SOCKADDR_IN serverAddr;
  int sockAddrSize = sizeof (SOCKADDR), result;
  const int resp = 1;
  fd_set wr_set = {1, {0}};
  TIMEVAL tval;
  unsigned long argp;
  char tmpStr[256];

  //- connection test
  if (sConnectedFlag)
    return;

  ::strcpy(sCurrentAddress, ip_address);

  tval.tv_sec = sTimeout;
  tval.tv_usec = 0;

  //- build server socket address
  serverAddr.sin_family = AF_INET;
  serverAddr.sin_port = htons (SERVER_PORT);

  if ( (serverAddr.sin_addr.s_addr = inet_addr(ip_address)) == -1 )
  {
    throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                  "Bad server address.",
                                  "SocketLecroy::TCP_Connect( ).");
  }

  //- create client's socket
  if ( (hSocket = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET )
  {
    throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                  "Unable to create client's socket.",
                                  "SocketLecroy::TCP_Connect( ).");
  }

  if ( setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (char*)&resp, sizeof(resp)) != 0 )
  {
    throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                  "Unable to set socket option to TCP_NODELAY.",
                                  "SocketLecroy::TCP_Connect( ).");
  }

  wr_set.fd_array[0] = hSocket;

  argp = 1;//-non blocking mode
  ioctlsocket(hSocket, FIONBIO, &argp);

  int status = connect(hSocket, (SOCKADDR FAR *) &serverAddr, sockAddrSize);
  int error_code = WSAGetLastError();

  //- already connected !
  if ( status && error_code == WSAEISCONN )
    return;
  if( status != 0 )  // We are not connected : so retry
  {
    if ( error_code == WSAEINPROGRESS || error_code == WSAEWOULDBLOCK ) // But the connection is in progress
    {
      int nb = 0;
      while ( nb++ < 5 ) // We will attempt to connect every 150 ms for 5 times max.
      {
        status = ::connect(hSocket, ( sockaddr *)&serverAddr, sizeof(serverAddr));
        error_code = WSAGetLastError();
        if ( status != 0 ) // Still not connected
        {
          if ( errno == WSAEISCONN ) // This is the right error !
          {
            Sleep(150);  // Sleep for 150 ms
          }
        }// Connection is OK.
        else
          break;
      } //- end while // Too much attempts, so failure !
      if ( nb >= 5 )
      {
        throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                      "Too much attempt to (re)build socket connection.",
                                      "SocketLecroy::TCP_Connect( ).");
      }
    }// TODO : throw ; // Not the right error, so failure !
  }// Connected at first attempt !

  result = select(hSocket, NULL, &wr_set, NULL, &tval);

  argp = 0;//-blocking mode
  ioctlsocket(hSocket, FIONBIO, &argp);

  //- connect to server (scope)
  if (result == SOCKET_ERROR)
  {
    sprintf(tmpStr, "Unable to make connection to IP:%s", ip_address);
    throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                  tmpStr,
                                  "SocketLecroy::TCP_Connect( ).");
  }

  sConnectedFlag = true;
}

//- DisconnectFromScope: disconnect from a network device
void SocketLecroy::TCP_Disconnect(void)
{
  if (sConnectedFlag)
  {
    closesocket(hSocket);
    sConnectedFlag = FALSE;
  }
}

//- Clear a connection
void SocketLecroy::TCP_ClearDevice(void) throw (lecroy::SocketException)
{
  if ( !sConnectedFlag )
    throw lecroy::SocketException("COMMUNICATION_BROKEN",
                                  "Disconnection already done.",
                                  "SocketLecroy::TCP_ClearDevice( ).");

  TCP_Disconnect();
  TCP_Connect(sCurrentAddress);
}

//- Send commands to the remote device
void SocketLecroy::TCP_WriteDevice(char *buf, int len, bool eoi_flag) throw (lecroy::SocketException)
{
  TCP_HEADER header;
  int result, bytes_more, bytes_xferd;
  char *idxPtr;

  //- test connection
  if ( !sConnectedFlag )
    throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                  "Device not connected.",
                                  "SocketLecroy::TCP_WriteDevice( ).");

  if (len < CMD_BUF_LEN)
    strcpy(sCommandBuffer, buf);

  //- set the header info
  header.bEOI_Flag = DATA_FLAG;
  header.bEOI_Flag |= (eoi_flag)? EOI_FLAG:0;
  header.reserved[0] = 1;
  header.reserved[1] = 0;
  header.reserved[2] = 0;
  header.iLength = htonl(len);

  //- write the header first
  if (send(hSocket, (char *) &header, sizeof(TCP_HEADER), 0) != sizeof(TCP_HEADER))
  {
    throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                  "Unable to send header info to the server.",
                                  "SocketLecroy::TCP_WriteDevice( ).");
  }

  bytes_more = len;
  idxPtr = buf;
  bytes_xferd = 0;
  while (1)
  {
    //- then write the rest of the block
    idxPtr = buf + bytes_xferd;

    if ((result = send(hSocket, (char *) idxPtr, bytes_more, 0)) < 0)
    {
      throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                    "Unable to send data to the server.",
                                    "SocketLecroy::TCP_WriteDevice( ).");
    }

    bytes_xferd += result;
    bytes_more -= result;
    if (bytes_more <= 0)
      break;
  }
}

//- Read the device answer
void SocketLecroy::TCP_ReadDevice(char *buf, int len, int *recv_count) throw (lecroy::SocketException)
{
  TCP_HEADER header;
  int result, accum, space_left, bytes_more, buf_count;
  char tmpStr[256];
  char *idxPtr;
  fd_set rd_set = {1, {0}};
  TIMEVAL tval;

  //- test connection
  if ( !sConnectedFlag )
    throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                  "Device not connected.",
                                  "SocketLecroy::TCP_ReadDevice( ).");

  *recv_count = 0;

  if (!buf)
    throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                  "Buffer memory not allocated.",
                                  "SocketLecroy::TCP_ReadDevice( ).");

  rd_set.fd_array[0] = hSocket;
  tval.tv_sec = sTimeout;
  tval.tv_usec = 0;

  ::memset(buf, 0, len);
  buf_count = 0;
  space_left = len;

  while (1)
  {
    result = select(hSocket, &rd_set, NULL, NULL, &tval);
    if ( !result || result == SOCKET_ERROR)
    {
      TCP_ClearDevice();
      throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                    "Read Timeout.",
                                    "SocketLecroy::TCP_ReadDevice( ).");
    }
    //- get the header info first
    accum = 0;
    while (1)
    {
      ::memset(&header, 0, sizeof(TCP_HEADER));
      if ( (result = recv(hSocket, (char *) &header + accum, sizeof(header) - accum, 0)) < 0 )
      {
        TCP_ClearDevice();
        throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                      "Unable to receive header info from the server.",
                                      "SocketLecroy::TCP_ReadDevice( ).");
      }

      accum += result;
      if (accum>=sizeof(header))
        break;
    }

    header.iLength = ntohl(header.iLength);

    //- only read to len amount
    if ( header.iLength > space_left )
    {
      header.iLength = space_left;
      throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                    "Read buffer size is too small.",
                                    "SocketLecroy::TCP_ReadDevice( ).");
    }

    //- read the rest of the block
    accum = 0;
    while (1)
    {
      idxPtr = buf + (buf_count + accum);
      bytes_more = header.iLength - accum;
      if ((space_left-accum) < TCP_MINIMUM_PACKET_SIZE)
      {
        TCP_ClearDevice();
        sprintf(tmpStr, "Read buffer needs to be adjusted, must be minimum of %d bytes", TCP_MINIMUM_PACKET_SIZE);
        throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                      tmpStr,
                                      "SocketLecroy::TCP_ReadDevice( ).");
      }

      if ( (result = recv(hSocket, (char *) idxPtr, (bytes_more>2048)?2048:bytes_more, 0)) < 0 )
      {
        TCP_ClearDevice();
        //-MessageBox(0, "Unable to receive data from the server.", "ERROR", MB_OK);
        throw lecroy::SocketException("COMMUNICATION_BROKEN ",
                                      "Unable to receive data from the server",
                                      "SocketLecroy::TCP_ReadDevice( ).");
      }

      accum += result;
      if (accum >= header.iLength)
        break;
      if ((accum + buf_count) >= len)
        break;
    }
    buf_count += accum;
    space_left -= accum;

    if (header.bEOI_Flag & EOI_FLAG)
      break;
    if (space_left <= 0)
      break;
  }

  *recv_count = buf_count;
}