source: orxonox.OLD/branches/network/src/lib/network/network_game_manager.cc @ 6917

/*
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

### File Specific:
   main-programmer: Benjamin Wuest
   co-programmer: ...
*/


/* this is for debug output. It just says, that all calls to PRINT() belong to the DEBUG_MODULE_NETWORK module
   For more information refere to https://www.orxonox.net/cgi-bin/trac.cgi/wiki/DebugOutput
*/
#define DEBUG_MODULE_NETWORK

#include "factory.h"
#include "network_stream.h"
#include "converter.h"

#include "p_node.h"
#include "state.h"
#include "game_world.h"
#include "world_entity.h"
#include "playable.h"
#include "player.h"
#include "shared_network_data.h"

#include "class_list.h"

/* include your own header */
#include "network_game_manager.h"


/* using namespace std is default, this needs to be here */
using namespace std;

NetworkGameManager* NetworkGameManager::singletonRef = NULL;

/*!
 * Standard constructor
 */
NetworkGameManager::NetworkGameManager()
  : Synchronizeable()
{
  PRINTF(0)("START\n");

  /* set the class id for the base object */
  this->setClassID(CL_NETWORK_GAME_MANAGER, "NetworkGameManager");

  hasRequestedWorld = false;
  this->setSynchronized(true);
}

/*!
 * Standard destructor
 */
NetworkGameManager::~NetworkGameManager()
{
  for ( int i = 0; i<outBuffer.size(); i++)
  {
    if ( outBuffer[i].buffer )
      delete outBuffer[i].buffer;
  }

}


int NetworkGameManager::writeBytes(const byte* data, int length, int sender)
{
  int i = 0;
  byte b;

  while ( i<length )
  {
    b = data[i++];

    /**************** Commands only processed by servers ****************/
    if ( isServer() )
    {
      if ( b == NET_REQUEST_CREATE )
      {
        if ( !handleRequestCreate( i, data, length, sender ) )
          return i;
        continue;
      }
      else if ( b == NET_REQUEST_REMOVE )
      {
        if ( !handleRequestRemove( i, data, length, sender ) )
          return i;
        continue;
      }
      else if ( b == NET_REQUEST_PNODE_PATH )
      {
        if ( !handleRequestPNodePath( i, data, length, sender ) )
          return i;
        continue;
      }
    }
    else
    {
      /**************** Commands only processed by clients ****************/
      if ( b == NET_CREATE_ENTITY )
      {
        PRINTF(0)("CREATE_ENTITY\n");
        if ( !handleCreateEntity( i, data, length, sender ) )
          return i;
        continue;
      }
      else if ( b == NET_REMOVE_ENTITY )
      {
        if ( !handleRemoveEntity( i, data, length, sender ) )
          return i;
        continue;
      }
      else if ( b == NET_CREATE_ENTITY_LIST )
      {
        if ( !handleCreateEntityList( i, data, length, sender ) )
          return i;
        continue;
      }
      else if ( b == NET_REMOVE_ENTITY_LIST )
      {
        if ( !handleRemoveEntityList( i, data, length, sender ) )
          return i;
        continue;
      }
      else if ( b == NET_YOU_ARE_ENTITY )
      {
        if ( !handleYouAreEntity( i, data, length, sender ) )
          return i;
        continue;
      }
    }

    /**************** Commands processed by servers and clients ****************/
    if ( b == NET_REQUEST_ENTITY_LIST )
    {
      sendEntityList( sender );
      continue;
    }
    else if ( b == NET_REQUEST_SYNC )
    {
      if ( !handleRequestSync( i, data, length, sender ) )
        return i;
      continue;
    }


    PRINTF(1)("Network is asynchronous: couldn't decode the command sent by %i\n", sender);
    PRINTF(1)("Probably this is because the network protocol has different \n");
    PRINTF(1)("versions or there occured an error in the sending algorithm\n");
    PRINTF(1)("Data is not in the right format! i=%d\n", i);
    return i;
  }

  return i;
}

int NetworkGameManager::readBytes(byte* data, int maxLength, int * reciever)
{
  if ( !isServer() && !hasRequestedWorld )
  {
    assert( maxLength >= 1 );
    data[0] = NET_REQUEST_ENTITY_LIST;
    hasRequestedWorld = true;
    return 1;
  }

  for ( int i = 0; i<outBuffer.size(); i++ )
  {
    *reciever = i;
    if ( outBuffer[i].length>0 )
    {
      int nbytes = outBuffer[i].length;
      outBuffer[i].length = 0;

      if ( nbytes > maxLength )
      {
        PRINTF(1)("OutBuffer.length (%d) > (%d) networkStreamBuffer.maxLength\n", nbytes, maxLength);
        return 0;
      }

      memcpy(data, outBuffer[i].buffer, nbytes);
      return nbytes;
    }
  }

  return 0;
}

void NetworkGameManager::writeDebug() const
{
}

void NetworkGameManager::readDebug() const
{
}


/*!
 * Checks whether this is connected to a server or a client
 * and afterwards creates the needed entity
 * @param classID: The ID of the class of which an entity should be created
 */
int NetworkGameManager::createEntity( ClassID classID, int owner )
{
  if ( this->isServer())
  {
    if ( SharedNetworkData::getInstance()->getNewUniqueID() < 0 )
    {
      PRINTF(1)("Cannot create entity! There are no more uniqueIDs left!\n");
      return -1;
    }
    return this->executeCreateEntity( classID, SharedNetworkData::getInstance()->getNewUniqueID(), owner );
  }
  else
  {
    this->requestCreateEntity( classID );
    return -1;
  }
}


/*!
 * Checks whether this is connected to a server or a client
 * and afterwards creates the needed entity
 * @param classID: The ID of the class of which an entity should be created
 */
BaseObject* NetworkGameManager::createEntity(const TiXmlElement* element)
{
  if ( this->isServer() )
  {
    if ( SharedNetworkData::getInstance()->getNewUniqueID() < 0 )
    {
      PRINTF(1)("Cannot create entity! There are no more uniqueIDs left!\n");
      return NULL;
    }

    BaseObject * b = Factory::fabricate( element );

    if ( !b )
    {
      PRINTF(1)("Could not fabricate Object with className %s\n", element->Value() );
      return NULL;
    }


    if ( b->isA(CL_SYNCHRONIZEABLE) )
    {
      Synchronizeable * s = dynamic_cast<Synchronizeable*>(b);
      s->setUniqueID( SharedNetworkData::getInstance()->getNewUniqueID() );
      s->setOwner( 0 );
      // all entities created via this function are added automaticaly to the synchronizeable list
      s->setSynchronized(true);
      return b;
    }
    else
    {
      PRINTF(1)("Class %s is not a synchronizeable!\n", b->getClassName() );
      delete b;
    }

  }
  else

  {
    PRINTF(1)("This node is not a server and cannot create id %x\n", element->Value());
  }
  return NULL;
}


/*!
 * Checks whether this is connected to a server or a client
 * and afterwards removes the specified entity
 * @param uniqueID: The ID of the entity object which should be removed
 */
void NetworkGameManager::removeEntity(int uniqueID)
{
  if ( this->isServer() )
  {
    this->executeRemoveEntity( uniqueID );
  }
  else
  {
    this->requestRemoveEntity( uniqueID );
  }
}



/*!
 * Creates the needed entity on the server if possible
 * @param classID: The ID of the class of which an entity should be created
 */
void NetworkGameManager::requestCreateEntity(ClassID classID)
{
  for ( int i = 0; i<outBuffer.size(); i++)
  {
    if ( !this->networkStream->isUserIdActive( i ) )
      continue;

    if ( !writeToClientBuffer( outBuffer[i], (byte)NET_REQUEST_CREATE ) )
      return;
    if ( !writeToClientBuffer( outBuffer[i], (int)classID ) )
      return;
  }
}

/*!
 * Removes the specified entity on the server
 * @param uniqueID: The ID of the entity object which should be removed
 */
void NetworkGameManager::requestRemoveEntity(int uniqueID)
{
  for ( int i = 0; i<outBuffer.size(); i++)
  {
    if ( !this->networkStream->isUserIdActive( i ) )
      continue;

    if ( !writeToClientBuffer( outBuffer[i], (byte)NET_REQUEST_REMOVE ) )
      return;
    if ( !writeToClientBuffer( outBuffer[i], uniqueID ) )
      return;
  }
}

/*!
 * Creates the needed entity if possible
 * This function is called if this is a server
 * @param classID: The ID of the class of which an entity should be created
 */
int NetworkGameManager::executeCreateEntity(ClassID classID, int uniqueID, int owner)
{
  for ( int i = 0; i<outBuffer.size(); i++)
  {
    if ( !this->networkStream->isUserIdActive( i ) )
      continue;

    if ( !writeToClientBuffer( outBuffer[i], (byte)NET_CREATE_ENTITY ) )
      return -1;
    if ( !writeToClientBuffer( outBuffer[i], (int)classID ) )
      return -1;
    if ( !writeToClientBuffer( outBuffer[i], uniqueID ) )
      return -1;
    if ( !writeToClientBuffer( outBuffer[i], owner ) )
      return -1;
  }

  PRINTF(0)("ExecuteCreateEntity: server side: classID: %x, uniqueID: %i, owner: %i\n", classID, uniqueID, owner);
  doCreateEntity( classID, uniqueID, owner );

  return uniqueID;
}

/*!
 * Removes the specified entity
 * This function is called if this is a server
 * @param uniqueID: The ID of the entity object which should be removed
 */
void NetworkGameManager::executeRemoveEntity(int uniqueID)
{
  for ( int i = 0; i<outBuffer.size(); i++)
  {
    if ( !this->networkStream->isUserIdActive( i ) )
      continue;

    if ( !writeToClientBuffer( outBuffer[i], (byte)NET_REMOVE_ENTITY ) )
      return;
    if ( !writeToClientBuffer( outBuffer[i], uniqueID ) )
      return;
  }

  doRemoveEntity(uniqueID);
}

/*!
 * Checks whether it is possible to create an entity of a given class
 * @return: true if the entity can be created, false otherwise
 */
bool NetworkGameManager::canCreateEntity(ClassID classID)
{
  return true;
}

/*!
 * Sends the Entities to the new connected client
 * @param userID: The ID of the user
 */
void NetworkGameManager::sendEntityList( int userID )
{
  if ( !isServer() )
    return;

  if ( userID >= outBuffer.size() )
    resizeBufferVector( userID );

  SynchronizeableList::const_iterator it, e;

  it = this->networkStream->getSyncBegin();
  e = this->networkStream->getSyncEnd();

  // send the packet header
  if ( !writeToClientBuffer( outBuffer[userID], (byte)NET_CREATE_ENTITY_LIST ) )
    return;

  // send the number of entities: -2 because you must not send network_game_manager and handshake
  if ( !writeToClientBuffer( outBuffer[userID], networkStream->getSyncCount() ) )
    return;

  //PRINTF(0)("SendEntityList: n = %d\n", networkStream->getSyncCount()-2 );

  // first send the NullParent
  if ( !writeToClientBuffer( outBuffer[userID], (int)PNode::getNullParent()->getLeafClassID()) )
    return;
  if ( !writeToClientBuffer( outBuffer[userID], (int)PNode::getNullParent()->getUniqueID()) )
    return;
  if ( !writeToClientBuffer( outBuffer[userID], (int)PNode::getNullParent()->getOwner()) )
    return;

  // now send the rest of the entities
  while ( it != e )
  {
    if( (*it)->beSynchronized() && (*it) != PNode::getNullParent())
    {
      PRINTF(0)("SENDING ENTITY %s classid: %x, uniqueid %d\n", (*it)->getClassName(), (*it)->getLeafClassID(), (*it)->getUniqueID() );
      if ( !writeToClientBuffer( outBuffer[userID], (int)((*it)->getLeafClassID()) ) )
        return;

      if ( !writeToClientBuffer( outBuffer[userID], (int)((*it)->getUniqueID()) ) )
        return;

      if ( !writeToClientBuffer( outBuffer[userID], (int)((*it)->getOwner()) ) )
        return;
    }
    it++;
  }

  signalNewPlayer( userID );
}



bool NetworkGameManager::signalNewPlayer(int userId)
{
  if ( userId >= outBuffer.size() )
    resizeBufferVector( userId );

  /* create new playable for Player*/
  PRINTF(0)("Request for creation: %i\n", userId);
  int uniqueId = this->createEntity(CL_SPACE_SHIP, userId);
  PRINTF(0)("Request for creation: userid: %i, uniqueid: %i\n", userId, uniqueId);
  this->sendYouAre(uniqueId, userId);

}



bool NetworkGameManager::signalLeftPlayer(int userID)
{
  const std::list<BaseObject*>* playableList = ClassList::getList(CL_PLAYABLE);
  std::list<BaseObject*>::const_iterator it = playableList->begin();

  for(; it != playableList->end(); it++)
  {
    if( dynamic_cast<Synchronizeable*>(*it)->getOwner() == userID )
    {
      PRINTF(0)("remove playable from %i\n", userID);
      this->removeEntity(dynamic_cast<Synchronizeable*>(*it)->getUniqueID());
      return true;
    }
  }
  return false;
}


/**
 * Creates a buffer for user n
 * @param n The ID of the user
 */
void NetworkGameManager::resizeBufferVector( int n )
{
  for ( int i = outBuffer.size(); i<=n; i++)
  {
    clientBuffer outBuf;

    outBuf.length = 0;

    outBuf.maxLength = 5*1024;

    outBuf.buffer = new byte[5*1014];

    outBuffer.push_back(outBuf);
  }
}

/**
 * Creates the entity on this host
 * @param classID: ClassID of the entity to create
 * @param uniqueID: Unique ID to assign to the synchronizeable
 * @param owner: owner of this synchronizealbe
 */
BaseObject* NetworkGameManager::doCreateEntity( ClassID classID, int uniqueID, int owner )
{
  PRINTF(0)("Creating Entity via Factory: classid: %x, uniqueID: %i, owner: %i\n", classID, uniqueID, owner);

  BaseObject * b;
  /* These are some small exeptions in creation: Not all objects can/should be created via Factory */
  /* Exception 1: NullParent */
  if( classID == CL_NULL_PARENT)
  {
    b = (BaseObject*)PNode::getNullParent();
  }
  else
    b = Factory::fabricate( classID );

  if ( !b )
  {
    PRINTF(1)("Could not fabricate Object with classID %x\n", classID);
    return NULL;
  }

  if ( b->isA(CL_SYNCHRONIZEABLE) )
  {
    Synchronizeable * s = dynamic_cast<Synchronizeable*>(b);
    s->setUniqueID( uniqueID );
    s->setOwner( owner );
    s->setSynchronized(true);
    //this->networkStream->connectSynchronizeable( *s );
    if ( !isServer() )
      s->setIsOutOfSync( true );
    PRINTF(0)("Fabricated %s with id %d\n", s->getClassName(), s->getUniqueID());

    //HACK: hack to prevent collision
    if ( b->isA(CL_WORLD_ENTITY) && !b->isA(CL_PLAYABLE) )
    {
      if ( SharedNetworkData::getInstance()->getHostID()!=0 )
      {
        static Vector pos = Vector(1000.0, 1000.0, 1000.0);
        PNode *p = dynamic_cast<PNode*>(b);
        p->setAbsCoor(pos);
        p->updateNode(0);
        pos += Vector(1000.0, 1000.0, 1000.0);
      }
    }

    return b;
  }
  else
  {
    PRINTF(1)("Class with ID %x is not a synchronizeable!", (int)classID);
    delete b;
  }
  return NULL;
}

/**
 * Removes a entity on this host
 * @param uniqueID: unique ID assigned with the entity to remove
 */
void NetworkGameManager::doRemoveEntity( int uniqueID )
{
  SynchronizeableList::const_iterator it,e;
  it = this->networkStream->getSyncBegin();
  e = this->networkStream->getSyncEnd();

  while ( it != e )
  {
    if ( (*it)->getUniqueID() == uniqueID )
    {
      assert((*it)->isA(CL_WORLD_ENTITY));
      dynamic_cast<WorldEntity*>(*it)->toList(OM_DEAD);
      break;
    }
    it++;
  }
}

/**
 * Tell the synchronizeable that a user's synchronizeable is out of sync
 * @param uniqueID: unique ID assigned with the entity which is out of sync
 * @param userID: user ID who's synchronizeable is out of sync
 */
void NetworkGameManager::doRequestSync( int uniqueID, int userID )
{
  SynchronizeableList::const_iterator it,e;
  it = this->networkStream->getSyncBegin();
  e = this->networkStream->getSyncEnd();

  while ( it != e )
  {
    if ( (*it)->getUniqueID() == uniqueID )
    {
      (*it)->requestSync( userID );
      break;
    }
    it++;
  }
}

/**
 * Copies length bytes to the clientBuffer with error checking
 * @param clientBuffer: the clientBuffer to write to
 * @param data: buffer to the data
 * @param length: length of data
 * @return false on error true else
 */
bool NetworkGameManager::writeToClientBuffer( clientBuffer &cb, byte * data, int length )
{
  if ( length > cb.maxLength-cb.length )
  {
    PRINTF(1)("No space left in clientBuffer\n");
    return false;
  }

  memcpy( cb.buffer+cb.length, data, length );
  return true;
}

/**
 * Reads data from clientBuffer with error checking
 * @param clientBuffer: the clientBuffer to read from
 * @param data: pointer to the buffer
 * @param length:
 * @return
 */
bool NetworkGameManager::readFromClientBuffer( clientBuffer &cb, byte * data, int length )
{
  if ( cb.length < length )
  {
    PRINTF(0)("There is not enough data in clientBuffer\n");
    return 0;
  }

  memcpy( data, cb.buffer+cb.length-length, length );
  return true;
}

/**
 * Tells this client that he has to control this entity
 * @param uniqueID: the entity's uniqeID
 */
void NetworkGameManager::doYouAre( int uniqueID )
{

  SynchronizeableList::const_iterator it = this->networkStream->getSyncBegin();

  Playable *p = NULL;
  Synchronizeable *s = NULL;

  for ( ; it !=networkStream->getSyncEnd(); it++ )
  {
    if ( (*it)->getUniqueID()==uniqueID )
    {
      if ( (*it)->isA( CL_SYNCHRONIZEABLE ) )
      {
        s = dynamic_cast<Synchronizeable*>(*it);
      }
      if ( (*it)->isA( CL_PLAYABLE ) )
      {
        p = dynamic_cast<Playable*>(*it);
        break;
      } else
      {
        PRINTF(1)("UniqueID is not a Playable\n");
      }
    }
  }

  Player* player = State::getPlayer();
  assert(p != NULL);
  assert(s != NULL);
  assert(player != NULL);

  s->setIsOutOfSync( true );

  PRINTF(0)("uniqueID = %d\n", s->getUniqueID());

  player->setControllable(p);


}

/**
 * Tells a remote client that he has to control this entity
 * @param uniqueID: the entity's uniqeID
 * @param userID: the users ID
 */
void NetworkGameManager::sendYouAre( int uniqueID, int userID )
{
  if ( !isServer() )
    return;

  if ( userID != 0 )
  {
    if ( !writeToClientBuffer( outBuffer[userID], (byte)NET_YOU_ARE_ENTITY ) )
      return;

    if ( !writeToClientBuffer( outBuffer[userID], uniqueID ) )
      return;
  }
  else
  {
    doYouAre(uniqueID);
  }
}

bool NetworkGameManager::handleRequestCreate( int & i, const byte * data, int length, int sender )
{
  if ( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read classID from buffer! Not enough data left!\n");
    return false;
  }
  int classID;
  i += Converter::byteArrayToInt( &data[i], &classID );

  createEntity( (ClassID)classID );

  return true;
}

bool NetworkGameManager::handleRequestRemove( int & i, const byte * data, int length, int sender )
{
  if ( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read uniqueID from buffer! Not enough data left!\n");
    return false;
  }
  int uniqueID;
  i += Converter::byteArrayToInt( &data[i], &uniqueID );

  removeEntity( uniqueID );

  return true;
}

bool NetworkGameManager::handleCreateEntity( int & i, const byte * data, int length, int sender )
{
  if ( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read classID from buffer! Not enough data left!\n");
    return false;
  }
  int classID;
  i += Converter::byteArrayToInt( &data[i], &classID );

  if ( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read uniqueID from buffer! Not enough data left!\n");
    return false;
  }
  int uniqueID;
  i += Converter::byteArrayToInt( &data[i], &uniqueID );

  if ( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read owner from buffer! Not enough data left!\n");
    return false;
  }
  int owner;
  i += Converter::byteArrayToInt( &data[i], &owner );

  PRINTF(0)("handleCreateEntity: client side: classID: %x, uniqueID: %i, owner: %i\n", classID, uniqueID, owner);
  doCreateEntity( (ClassID)classID, uniqueID, owner );

  return true;
}

bool NetworkGameManager::handleRemoveEntity( int & i, const byte * data, int length, int sender )
{
  if ( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read uniqueID from buffer! Not enough data left!\n");
    return false;
  }
  int uniqueID;
  i += Converter::byteArrayToInt( &data[i], &uniqueID );

  doRemoveEntity( uniqueID );

  return true;
}

bool NetworkGameManager::handleCreateEntityList( int & i, const byte * data, int length, int sender )
{
  if ( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read n from buffer! Not enough data left!\n");
    return false;
  }

  PRINTF(0)("HandleCreateEntityList:  data[i..i+3] = %d %d %d %d\n", data[i], data[i+1], data[i+2], data[i+3]);

  int n;
  i += Converter::byteArrayToInt( &data[i], &n );


  PRINTF(0)("HandleCreateEntityList: n = %d\n", n);

  int classID, uniqueID, owner;

  for ( int j = 0; j<n; j++ )
  {

    if ( INTSIZE > length-i )
    {
      PRINTF(1)("Cannot read classID from buffer! Not enough data left!\n");
      return false;
    }
    i += Converter::byteArrayToInt( &data[i], &classID );

    if ( INTSIZE > length-i )
    {
      PRINTF(1)("Cannot read uniqueID from buffer! Not enough data left!\n");
      return false;
    }
    i += Converter::byteArrayToInt( &data[i], &uniqueID );

    if ( INTSIZE > length-i )
    {
      PRINTF(1)("Cannot read owner from buffer! Not enough data left!\n");
      return false;
    }
    i += Converter::byteArrayToInt( &data[i], &owner );

    if ( classID != CL_NETWORK_GAME_MANAGER && classID != CL_HANDSHAKE )
    {
      BaseObject* b = doCreateEntity( (ClassID)classID, uniqueID, owner );
    }

  }

  return true;
}

bool NetworkGameManager::handleRemoveEntityList( int & i, const byte * data, int length, int sender )
{
  if ( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read n from buffer! Not enough data left!\n");
    return false;
  }
  int n;
  i += Converter::byteArrayToInt( &data[i], &n );

  int uniqueID;

  for ( int j = 0; j<n; j++ )
  {

    if ( INTSIZE > length-i )
    {
      PRINTF(1)("Cannot read uniqueID from buffer! Not enough data left!\n");
      return false;
    }
    i += Converter::byteArrayToInt( &data[i], &uniqueID );

    doRemoveEntity( uniqueID );
  }

  return true;
}

bool NetworkGameManager::handleYouAreEntity( int & i, const byte * data, int length, int sender )
{
  if ( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read uniqueID from buffer! Not enough data left!\n");
    return false;
  }

  int uniqueID;
  i += Converter::byteArrayToInt( &data[i], &uniqueID );

  doYouAre( uniqueID );

  return true;
}

bool NetworkGameManager::handleRequestSync( int & i, const byte * data, int length, int sender )
{
  if ( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read uniqueID from buffer! Not enough data left!\n");
    return false;
  }
  int uniqueID;
  i += Converter::byteArrayToInt( &data[i], &uniqueID );

  PRINTF(0)("handleRequestSync %d %d\n", uniqueID, sender);
  doRequestSync( uniqueID, sender );

  return true;
}


/**
 *  handles the network signal NET_REQUEST_PNODE_PATH
 * @param i byte offset in the buffer
 * @param data data array
 * @param length length of the data arary
 * @param sender the sender id
 * @return true if process terminated sucessfully
 */
bool NetworkGameManager::handleRequestPNodePath(int& i, const byte* data, int length, int sender)
{
  if( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read n from buffer! Not enough data left!\n");
    return false;
  }
  PRINTF(0)("HandleRequestPNodePath:  data[i..i+3] = %d %d %d %d\n", data[i], data[i+1], data[i+2], data[i+3]);

  int uniqueID1, uniqueID2;
  if( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read uniqueID from buffer! Not enough data left!\n");
    return false;
  }
  i += Converter::byteArrayToInt( &data[i], &uniqueID1 );

  if( INTSIZE > length-i )
  {
    PRINTF(1)("Cannot read uniqueID from buffer! Not enough data left!\n");
    return false;
  }
  i += Converter::byteArrayToInt( &data[i], &uniqueID2 );


  PRINTF(0)("HandleRequestPNodePath: got a request for path from uid %i to uid %i\n", uniqueID1, uniqueID2);

  return true;
}


bool NetworkGameManager::writeToClientBuffer( clientBuffer & cb, byte b )
{
  if ( cb.maxLength-cb.length < 1 )
  {
    PRINTF(1)("Cannot write to clientBuffer! Not enough space for 1 byte\n");
    return false;
  }

  cb.buffer[cb.length++] = b;

  return true;
}

bool NetworkGameManager::writeToClientBuffer( clientBuffer & cb, int i )
{
  int n = Converter::intToByteArray( i, cb.buffer+cb.length, cb.maxLength-cb.length );
  cb.length += n;

  if ( n <= 0 )
  {
    PRINTF(1)("Cannot write to clientBuffer! Not enough space for 1 int\n");
    return false;
  }

  return true;
}

void NetworkGameManager::sync( int uniqueID, int owner )
{
  /*if ( owner==this->getHostID() )
  return;*/

  if ( !isServer() )
    executeRequestSync( uniqueID, 0 );
  else
    executeRequestSync( uniqueID, owner );
}

void NetworkGameManager::executeRequestSync( int uniqueID, int user )
{
  PRINTF(0)("executeRequestSync %d %d\n", uniqueID, user);
  if ( user >= outBuffer.size() )
    resizeBufferVector( user );

  if ( !writeToClientBuffer( outBuffer[user], (byte)NET_REQUEST_SYNC ) )
    return;
  if ( !writeToClientBuffer( outBuffer[user], uniqueID ) )
    return;
}