// %flair:license{
// This file is part of the Flair framework distributed under the
// CECILL-C License, Version 1.0.
// %flair:license}
#include "UdtSocket.h"
#include "ConnectionLayout.h"
#include <stdio.h>
#include <stdlib.h>
#include <QApplication>
#include <QtEndian>
#include <QDir>
#include <QDate>
#include "communication.h"
#include <zlib.h>
#include <assert.h>
#include <QThread>
#define COMPRESS_CHUNK 1024*100

#ifndef WIN32
#include <arpa/inet.h>
#else
#include <winsock2.h>
#include <ws2tcpip.h>
#endif

#define COMPUTE_UDT_STATS_TIMER 2000
#define HEARTBEAT_TIMER 200

using namespace std;

UdtSocket::UdtSocket(UDTSOCKET socket,QString name): QObject() {
  this->socket = socket;
  this->name=name;
  stop = false;
  destroySocket=true;
  socketType=unknown;
  total_received=0;
  pktSndLossTotal=0;
 
  bool blocking = false;
  if (UDT::setsockopt(socket, 0, UDT_RCVSYN, &blocking, sizeof(bool)) != 0)
    fprintf(stderr,"UDT::setsockopt error (UDT_RCVSYN)\n");
    
  heartbeat_timer = new QTimer(this);
  connect(heartbeat_timer, SIGNAL(timeout()), this, SLOT(heartbeat()));
  heartbeat_timer->start(HEARTBEAT_TIMER);
  
  udtstats_timer = new QTimer(this);
  connect(udtstats_timer, SIGNAL(timeout()), this, SLOT(getUTDStats()));
  udtstats_timer->start(COMPUTE_UDT_STATS_TIMER);
}

UdtSocket::~UdtSocket() {
  heartbeat_timer->stop();
  udtstats_timer->stop();
  if(destroySocket) UDT::close(socket);
}

void UdtSocket::setName(QString name) {
  fprintf(stderr,"  %s is %s\n",this->name.toLocal8Bit().constData(),name.toLocal8Bit().constData());
  this->name=name;
}

// send signal to uav, to check connectivity through a watchdog
// this is necessary because we use udt (udp based), and we cannot check
// disconnection of ground station
void UdtSocket::heartbeat(void) {
  char data = WATCHDOG_HEADER;
  quint64 sent=write(&data, 1,HEARTBEAT_TIMER,false);
  if (sent != 1 && UDT::getlasterror().getErrorCode() == 2001) {
    heartbeat_timer->stop();
  }
  
}

void UdtSocket::getUTDStats(void) {
  float rxRate=((float)total_received/(COMPUTE_UDT_STATS_TIMER/1000))/1000;//in Ko/s
  total_received=0;
  
  UDT::TRACEINFO perf;
  if (UDT::ERROR == UDT::perfmon(socket, &perf))   {
    fprintf(stderr,"perfmon: %s\n",UDT::getlasterror().getErrorMessage());
  }/* else {
    fprintf(stderr,"%s socket stats:\n",name.toLocal8Bit().constData());
    fprintf(stderr,"total number of sent packets, including retransmissions: %i\n",perf.pktSentTotal);
    fprintf(stderr,"total number of received packets: %i\n",perf.pktRecvTotal);
    fprintf(stderr,"total number of lost packets, measured in the sending side: %i\n",perf.pktSndLossTotal);
    fprintf(stderr,"total number of lost packets, measured in the receiving side: %i\n",perf.pktRcvLossTotal);
    fprintf(stderr,"total number of retransmitted packets, measured in the sending side: %i\n",perf.pktRetransTotal);
    fprintf(stderr,"total number of sent ACK packets: %i\n",perf.pktSentACKTotal);
    fprintf(stderr,"total number of received ACK packets: %i\n",perf.pktRecvACKTotal);
    fprintf(stderr,"total number of sent NAK packets: %i\n",perf.pktSentNAKTotal);
    fprintf(stderr,"total number of received NAK packets: %i\n",perf.pktRecvNAKTotal);
    fprintf(stderr,"round trip time: %fms\n",perf.msRTT);
      
  }*/
  bool loosingPackets=false;
  if(perf.pktSndLossTotal>pktSndLossTotal) loosingPackets=true;
  pktSndLossTotal=perf.pktSndLossTotal;
  stats=QString("rx rate %1kB/s, round trip %2ms, lost packets %3").arg(rxRate,0,'f',3).arg(perf.msRTT,0,'f',3).arg(perf.pktSndLossTotal);
  UDTStats(stats,loosingPackets);
}

QString UdtSocket::getUDTStats() {
  return stats;
}

void UdtSocket::kill(void) {
  stop = true;
  deleteLater();
}

void UdtSocket::receiveData(void) {
  int buf_size;
  int opt_size;
  UDT::getsockopt(socket, 0, UDT_RCVBUF, &buf_size, &opt_size);
  char *buf = (char *)malloc(buf_size);
  if (!buf) {
    fprintf(stderr,"error malloc UdtSocket::receiveData buffer\n");
    return;
  }
  char *uncompressbuf=(char *)malloc(COMPRESS_CHUNK);
  if (!uncompressbuf) {
    fprintf(stderr,"error malloc UdtSocket::receiveData uncompress buffer\n");
    free(buf);
    return;
  }
  //fprintf(stderr,stderr,"receiveData %x\n",thread());
  
  while (!stop) {
    QCoreApplication::processEvents();
    
    //we need to use epoll?
    //tests are showing that UDT::recvmsg is waiting for the entire timeout before returning
    //note that in flair::core the behaviour of UDT::recvmsg timeout is as expected
    //is it a difference between client and server??
    //tests also show that we need to recreate the eid every time, otherwise wait returns immediately
    int eid = UDT::epoll_create();
    if (eid < 0) {
      fprintf(stderr,"%s: epoll_create error (%s)\n",name.toLocal8Bit().constData(),UDT::getlasterror().getErrorMessage());
    }

    if (UDT::epoll_add_usock(eid, socket) < 0) {
      if (UDT::getlasterror().getErrorCode() == 5004) {
        fprintf(stderr,"disconnected from %s\n",name.toLocal8Bit().constData());
        heartbeat_timer->stop();
        deleteLater();
        stop=true;;
      } else {
        fprintf(stderr,"%s: epoll_add_usock error (%s)\n",name.toLocal8Bit().constData(),UDT::getlasterror().getErrorMessage());
      }
    }
  
    int num = 1;
    UDTSOCKET readfds;
  
    int rv = UDT::epoll_wait2(eid, &readfds, &num,NULL, NULL,100);
    if (rv == -1) {
      if (UDT::getlasterror().getErrorCode() != 6003)
        fprintf(stderr,"prob %i\n", UDT::getlasterror().getErrorCode());
    } else if(readfds==socket && num==1 && rv==1) {
       
      int size;
      do {
        size=UDT::recvmsg(socket, buf, buf_size);
      
        //fprintf(stderr,"recu %i\n",size);
        if (size > 0) {
          total_received+=size;
          
          switch ((unsigned char)buf[0]) {
            case ZLIB_HEADER: {
              ssize_t out_size;
              uncompressBuffer(buf, size, uncompressbuf, &out_size);
              if((unsigned char)uncompressbuf[0]==XML_HEADER && socketType==unknown) {
                socketType=gui;
                QString remoteName=ConnectionLayout::getDocRootName(uncompressbuf, out_size);
                setName(remoteName);
                emit newConnectionLayout(remoteName);//connection is Qt::BlockingQueuedConnection
              }
              emit dataReady(uncompressbuf, out_size);//connection is Qt::BlockingQueuedConnection, as we have only one buffer
              break;
            }
            case START_SENDING_FILES: {
              if((unsigned char)uncompressbuf[0]==XML_HEADER && socketType==unknown) {
                socketType=log;
              }
              setName("log files");
              heartbeat_timer->stop();
              emit newFileUI(socket);
              deleteLater();
              stop=true;
              destroySocket=false;
              break;
            }
            case XML_HEADER:
              if(socketType==unknown) {
                socketType=gui;
                QString remoteName=ConnectionLayout::getDocRootName(buf, size );
                setName(remoteName);
                emit newConnectionLayout(remoteName);
              }
            case DATAS_BIG_ENDIAN:
            case DATAS_LITTLE_ENDIAN:
              emit dataReady(buf, size );
              break;
            case CLOSING_CONNECTION:
              fprintf(stderr,"%s, connection closed\n",name.toLocal8Bit().constData());
              emit dataReady(buf, size );
              stop = true;
              heartbeat_timer->stop();
              deleteLater();
              break;
            default:
              fprintf(stderr,"trame non supportée %x\n", buf[0]);
          }
        } else {
          //not necessary to check, watchdog (heartbeat_timer) can do it
          //if(UDT::getlasterror().getErrorCode()!=6002 && !stop) 
            //fprintf(stderr,"udt socket: %s\n",UDT::getlasterror().getErrorMessage());
          //UDT::close(socket);//si deconnecté
          //free(buf);
          //break;
        }
      } while(size>0);
    } else {
      //not necessary to check, watchdog (heartbeat_timer) can do it
      //fprintf(stderr,"udt socket: %s\n",UDT::getlasterror().getErrorMessage());
    }
    UDT::epoll_remove_usock(eid, socket);
    UDT::epoll_release(eid);
  }
  
  free(uncompressbuf);
  free(buf);
  thread()->quit();
}

qint64 UdtSocket::write(const char *buf, qint64 size,int ttl,bool inOrder) {
  qint64 sent = UDT::sendmsg(socket, buf, size, ttl, inOrder);
  if (sent != size) {
    fprintf(stderr,"%s, error writting to udt (%s)\n",name.toLocal8Bit().constData(), UDT::getlasterror().getErrorMessage());
    if (UDT::getlasterror().getErrorCode() == 2001) {
      fprintf(stderr,"%s, closing connection\n",name.toLocal8Bit().constData());
      stop = true;
      heartbeat_timer->stop();
      deleteLater();
    }
  }
  return sent;
}

int UdtSocket::uncompressBuffer(char *in, ssize_t in_size, char *out,
                                       ssize_t *out_size) {
  int ret;
  unsigned have;
  z_stream strm;

  // allocate inflate state
  strm.zalloc = Z_NULL;
  strm.zfree = Z_NULL;
  strm.opaque = Z_NULL;
  strm.avail_in = 0;
  strm.next_in = Z_NULL;
  ret = inflateInit(&strm);
  if (ret != Z_OK)
    return ret;

  strm.avail_in = in_size;
  strm.next_in = (unsigned char *)in;
  strm.avail_out = COMPRESS_CHUNK;
  strm.next_out = (unsigned char *)out;

  ret = inflate(&strm, Z_NO_FLUSH);
  assert(ret != Z_STREAM_ERROR); // state not clobbered
  switch (ret) {
  case Z_NEED_DICT:
    ret = Z_DATA_ERROR; // and fall through
  case Z_DATA_ERROR:
  case Z_MEM_ERROR:
    (void)inflateEnd(&strm);
    return ret;
  }
  have = COMPRESS_CHUNK - strm.avail_out;
  *out_size = have;

  // clean up and return
  (void)inflateEnd(&strm);
  return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}