/////////////////////////////////////////////////////////////////////
//  socks.cpp   -   socket client and multi-threaded server        //
//                  prototype for project #2                       //
//  ver 1.2                                                        //
//  Language:       Visual C++, ver 6.0, SP 5                      //
//  Platform:       Dell Dimension 8100, Win 2000 Pro, SP 2        //
//  Application:    CSE691/791 - SWM&A Demonstration               //
//  Author:         Jim Fawcett, CST 2-187, Syracuse Univ          //
//                  (315) 443-3948, jfawcett@twcny.rr.com          //
/////////////////////////////////////////////////////////////////////

#include <iostream>
#include <process.h>
#include "socks.h"      // must put here due to dependencies in Win32 defs
#include "lockingPtr.h"
#include "sysUtils.h"
using namespace std;

/////////////////////////////////////////////////////////////////////
//  initialize static member
//
//CRITICAL_SECTION sockSvr::_cs;

//----< handle WinSock errors >--------------------------------------
//
//     enum reportMethod { console, window, exception };

void reportError(reportMethod rm, const char *msg) {

  safeOut sout(cout);
  sysError sysErr;
  int errType = 0;

  if(msg)
    sout << "\n  " << msg;
  switch(rm) {
    case console:
      errType = WSAGetLastError();
      sout << "\n  initialization error type: " << errType;
      sout << "\n  " << sysErr.getLastMsg() << "\n\n";
      break;
    case window :
      sout << "\n  window reporting not implemented yet\n\n";
      break;
    case exception:
      throw sysErr.getLastMsg();
    default :
      sout << "\n  invalid report method\n\n";
  }
}

//

//----< constructor >------------------------------------------------

sockClt::sockClt() {

  // load version 1.1 of winsock dll

  WORD wVersionRequested = MAKEWORD(1,1);   // requesting version 1.1
  WSAData wData;                            // startup data filled
                                            // by WSAStartup

  int err = WSAStartup(wVersionRequested, &wData);

  if(err == SOCKET_ERROR)
    reportError(console,"starting WinSock on client");

  // create TCP/IP socket object

  _client = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  
}

//----< attempt to connect to a server >-----------------------------

bool sockClt::connectTo(address &addr, int port) {

  // connect to server on specified address and port
  //   - note the IP address 127.0.0.1 refers to host machine

  _port = port;        // server port

  struct hostent *serverHostent;
  serverHostent = gethostbyname("Lusitania");
  
  SOCKADDR_IN tcpAddr;
  tcpAddr.sin_family = AF_INET;                       // TCP/IP
  tcpAddr.sin_addr.s_addr = inet_addr(addr.c_str());  // host machine
  tcpAddr.sin_port = htons(port);                     // server port

  int err = ::connect(_client, (sockaddr*)&tcpAddr, sizeof(tcpAddr));

  if(err == SOCKET_ERROR) {
    reportError(console,"client can't connect");
    return false;
  }
  return true;
}

//

//----< attempt to connect to a server >-----------------------------

bool sockClt::connectTo(const char *s, int port) {

  return connectTo(string(s), port);
}

//----< destructor >-------------------------------------------------

sockClt::~sockClt() {

  closesocket(_client);
  WSACleanup();
}

//----< insertion operator >-----------------------------------------

sockClt& sockClt::operator<<(std::string &s) {

  static char *msg = 
    "can't send all bytes in sockClt::operator<<(std::string &s)";
  int bytesSent = send(s.c_str());
  if(bytesSent != s.size())
    reportError(console,msg);
  return *this;
}
    
//----< insertion operator >-----------------------------------------

sockClt& sockClt::operator<<(const char *s) {

  return operator<<(string(s));
}
    
//----< extraction operator >----------------------------------------

sockClt& sockClt::operator>>(std::string &s) {

  const int bufferSize = MAX_MSG_SIZE;
  char buffer[bufferSize];
  int bytes = recv(_client,buffer,bufferSize,0);
  buffer[bytes] = '\0';
  s = buffer;
  return *this;
}

//

//----< send a block of bytes through socket connection >------------
//
//  attempts to guarantee that all bytes are sent
//
int sockClt::send(const char *block) {

  const char *msg = "send failed after 100 retries";
  const int sendRetries = 100;

  int blockLen = strlen(block);
  int bytesSent;
  int bytesLeft = blockLen;
  int blockIndx = 0;
  int count = 0;
  while(bytesLeft > 0) {
    bytesSent = ::send(_client,&block[blockIndx],bytesLeft,0);
    if(bytesSent == SOCKET_ERROR) {
      Sleep(50);
      ++count;
    }
    if(count==sendRetries) {
      reportError(console,msg);
      return bytesSent;
    }
    bytesLeft -= bytesSent;
    blockIndx += bytesSent;
  }
  return blockLen;
}

//----< client will stop receiving >---------------------------------

void sockClt::shutDownRecv() { shutdown(_client,SD_RECEIVE); }

//----< client will stop sending >-----------------------------------

void sockClt::shutDownSend() { shutdown(_client,SD_SEND); }

//----< client will stop sending and receiving >---------------------

void sockClt::shutDown() { 
  
  shutdown(_client,SD_BOTH); 
  closesocket(_client); 
}

//----< close socket connection >------------------------------------

void sockClt::close() { closesocket(_client); }

//

//----< constructor >------------------------------------------------

sockSvr::sockSvr(int port) : _listeningPort(port) {

  // load version 1.1 of winsock dll

  WORD wVersionRequested = MAKEWORD(1,1);   // requesting version 1.1
  WSAData wData;                            // startup data filled
                                            // by WSAStartup

  int err = WSAStartup(wVersionRequested, &wData);
  if(err == SOCKET_ERROR)
    reportError(console,"starting WinSock on server");

//  InitializeCriticalSection(&_cs);
}

//----< destructor >-------------------------------------------------

sockSvr::~sockSvr() {

//  DeleteCriticalSection(&_cs);
  closesocket(_listener);
  WSACleanup();
}

//

//----< send a block of bytes through socket connection >------------
//
//  attempts to guarantee that all bytes are sent
//
int sockSvr::send(SOCKET sock, const char *block) {

  static char *msg = "send failed after 100 retries";
  const int sendRetries = 100;

  int blockLen = strlen(block);
  int bytesSent;
  int bytesLeft = blockLen;
  int blockIndx = 0;
  int count = 0;
  while(bytesLeft > 0) {
    bytesSent = ::send(sock,&block[blockIndx],bytesLeft,0);

    if(bytesSent == SOCKET_ERROR) {
      Sleep(50);
      ++count;
    }
    if(count==sendRetries) {
      reportError(console,msg);
      return bytesSent;
    }
    bytesLeft -= bytesSent;
    blockIndx += bytesSent;
  }
  return blockLen;
}

//

//----< start up server >--------------------------------------------

void sockSvr::start() {

  // create TCP/IP socket object to listen for connection requests

  _listener = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

  // bind listner socket to specific port and network interface

  SOCKADDR_IN tcpAddr;
  tcpAddr.sin_family = AF_INET;             // use TCP/IP protocol
  tcpAddr.sin_port = htons(_listeningPort); // listening port
  tcpAddr.sin_addr.s_addr = INADDR_ANY;     // listen over all NICs
  int err = bind(_listener, (SOCKADDR*)&tcpAddr, sizeof(tcpAddr));

  safeOut sout(cout);

  if(err == SOCKET_ERROR) {
    reportError(console,"failed to bind");
    return;
  }

  // listen for incoming connection requests

  int backLog = 10;
  err = ::listen(_listener, backLog);

  if(err == SOCKET_ERROR) {
    reportError(console,"failed to start listening");
    return;
  }

//

  sout << "\n  waiting for incoming request";

  int size = sizeof(tcpAddr);

  while(1) {

    // block until a connection is established

    SOCKET toClient = accept(_listener, (SOCKADDR*)&tcpAddr, &size);      
    if(toClient == INVALID_SOCKET) {
      reportError(console,"could not create socket for new client");
      break;
    }
    sout << "\n  established connection with: "
         << inet_ntoa(tcpAddr.sin_addr) << " : " 
         << ntohs(tcpAddr.sin_port) << "\n";

    // got connection so spawn thread to read transferred data

    unsigned int threadID;

    HANDLE hThread = 
      (HANDLE)_beginthreadex(
        NULL, 0, threadProc, (void*)&toClient, 0, &threadID
      );
    CloseHandle(hThread);   // listener doesn't need to communicate
  }                         // with thread so close thread handle

}

//

//----< client connection thread processing >------------------------
//
//  With this ver 1.2 design, you must edit this function for any
//  given server application to get the processing you want.
//  Note carefully that this demonstration processing makes the
//  assumption:
//
//    Every client message results in a return server message
//    so the client must listen after every sent message,
//    otherwise the client/server pair will deadlock.
//
//  This design will be changed to be more generally useful in the
//  next release - presumably after you have turned in your second
//  project.
//
unsigned int __stdcall sockSvr::threadProc(void *pArgs) {

  SOCKET sock = *(SOCKET*)pArgs;
  char *msg = "server got your message";

  safeOut sout(cout);
  string save;
  const int bufSize = MAX_MSG_SIZE;
  char buffer[bufSize];
  int bytes;
  do {

    // recv reads all available bytes up to bufSize-1
    // if no data is available it blocks until data
    // becomes available or the connection closes

    bytes = recv(sock,buffer,bufSize-1,0);
    if(bytes == SOCKET_ERROR) {
      reportError(console,"\n  server error reading client socket");
      break;
    }
    buffer[bytes] = '\0';
    save = buffer;
    if(bytes > 0) {
      sout << "\n  message from client:  " << save.c_str();
      if(!send(sock,msg)) {
        sysError err;
        sout << err.getLastMsg();
      }
      else
        sout << "\n  reply sent to client: " << msg;
    }
  } while(bytes != 0);

  sout << "\n  server closing client thread";
  closesocket(sock);
  return 0;
}

//

//----< test stub >--------------------------------------------------

#ifdef TEST_SOCKS_CLIENT
#include "threads.h"
#include "sysUtils.h"

void main(int argc, char *argv[]) {

  safeOut sout(cout);
  sout << "\n  running client\n";

  sockClt client;
  if(!client.connectTo("127.0.0.1", 1024))
    return;
  else
    sout << "\n  connected to server";

  string sndMsg = "this is the first message from client";
  sout << "\n  sending to server:   " << sndMsg;
  client << sndMsg;

  string rcvMsg;
  client >> rcvMsg;
  sout << "\n  message from server: " << rcvMsg;

  sndMsg = "this is the last message from client";
  sout << "\n  sending to server:   " << sndMsg;
  client << sndMsg;

  client >> rcvMsg;
  sout << "\n  message from server: " << rcvMsg;

  sout << "\n  client shutting down";
  client.shutDown();

  sout << "\n\n";
}

#endif

//

#ifdef TEST_SOCKS_SERVER
void main() {

  cout << "\n  running server\n";
  try {
    sockSvr server(1024);
    server.start();
  }
  catch(...) {
    cout << "\n  can't create server - is there one already running?\n\n";
  }
}

#endif