/*
   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: Silvan Nellen
   co-programmer: Benjamin Wuest
*/

#define DEBUG_MODULE_NETWORK

#include "shared_network_data.h"
#include "network_stream.h"
#include "netdefs.h"

#include "state.h"

#include <cassert>

#include "synchronizeable.h"



/**
 *  default constructor
 */
Synchronizeable::Synchronizeable()
{
  this->setClassID(CL_SYNCHRONIZEABLE, "Synchronizeable");
  this->owner = -1;
  this->hostID = SharedNetworkData::getInstance()->getHostID();
  this->setIsServer(this->hostID == 0);
  this->uniqueID = NET_UID_UNASSIGNED;
  this->networkStream = NULL;
  this->bSynchronize = false;

  if( State::isOnline())
  {
    NetworkStream* nd = SharedNetworkData::getInstance()->getDefaultSyncStream();
    assert(nd != NULL);
    nd->connectSynchronizeable(*this);
    this->setUniqueID(SharedNetworkData::getInstance()->getNewUniqueID());
  }

  this->registerVar( new SynchronizeableString( &this->objectName, &this->objectName, "objectName" ) );
}



/**
 *  default destructor deletes all unneded stuff
 */
Synchronizeable::~Synchronizeable()
{
  if ( this->networkStream )
    this->networkStream->disconnectSynchronizeable(*this);
}

/**
 * Sets the server flag to a given value
 * @param isServer: the boolean value which the server flag is to set to
 */
void Synchronizeable::setIsServer(bool isServer)
{
  if( isServer )
    this->state = this->state | STATE_SERVER;
  else
    this->state = this->state & (~STATE_SERVER);
}


/**
 * Determines if the server flag is set
 * @return true, if the server flag is true, false else
 */
bool Synchronizeable::isServer()
{
  return (this->state & STATE_SERVER) >0;
}


/**
 * get the diff to last acked state of userId
 *
 * each synchrinizeable defines its own stack of states received and sent over the network. The stack contains
 * a per user entry for the last sent/received state This function returns a delta compressed state of the
 * synchronizeable. This state will be transmitted over the network to the other participants
 *
 * @param userId user to create diff for
 * @param data buffer to copy diff in
 * @param maxLength max bytes to copy into data
 * @param stateId id of current state
 * @param fromStateId the reference state for the delta state
 * @param priorityTH tells getStateDiff to not send element with priority \< priorityTH
 * @return n bytes copied into data
 */
int Synchronizeable::getStateDiff( int userId, byte* data, int maxLength, int stateId, int fromStateId, int priorityTH )
{
  //make sure this user has his history
  if ( sentStates.size() <= userId )
    sentStates.resize( userId+1 );

  //calculate needed memory
  int neededSize = 0;

  for ( SyncVarList::iterator it = syncVarList.begin(); it != syncVarList.end(); it++ )
    neededSize += (*it)->getSize();

  assert( neededSize <= maxLength );

  //remove older states from history than fromStateId
  StateHistory::iterator it = sentStates[userId].begin();

  while ( it != sentStates[userId].end() && (*it)->stateId < fromStateId )
    it++;
  ///FIXED: altered begin() -> end()
  if ( it != sentStates[userId].end() )
  {
    for ( StateHistory::iterator it2 = sentStates[userId].begin(); it2 != it; it2++ )
    {
      if ( (*it2)->data != NULL )
      {
        delete (*it2)->data;
        (*it2)->data = NULL;
      }
    }
    sentStates[userId].erase( sentStates[userId].begin(), it );
  }

  //find state to create diff from
  StateHistoryEntry * stateFrom = NULL;

  it = sentStates[userId].begin();
  while ( it != sentStates[userId].end() && (*it)->stateId != fromStateId )
    it++;

  if ( it == sentStates[userId].end() )
  {
    StateHistoryEntry * initialEntry = new StateHistoryEntry();

    initialEntry->stateId = fromStateId;
    initialEntry->dataLength = 0;
    initialEntry->data = NULL;

    stateFrom = initialEntry;
  }
  else
    stateFrom = (*it);

  StateHistoryEntry * stateTo = new StateHistoryEntry();

  stateTo->stateId = stateId;
  stateTo->dataLength = neededSize;
  stateTo->data = (byte*)malloc( neededSize );

  std::list<int>::iterator sizeIter = stateFrom->sizeList.begin();

  int i = 0;
  int n;

  // now do the actual synchronization: kick all variables to write into a common buffer
  for ( SyncVarList::iterator it = syncVarList.begin(); it != syncVarList.end(); it++ )
  {
    if ( (*it)->getPriority() >= priorityTH || sizeIter == stateFrom->sizeList.end() )
    {
      n = (*it)->writeToBuf( stateTo->data+i, stateTo->dataLength - i );
      stateTo->sizeList.push_back( n );
      i += n;
    }
    else
    {
      for ( int j = 0; j<(*sizeIter); j++ )
      {
        assert( i < stateFrom->dataLength );
        stateTo->data[i] = stateFrom->data[i];
        i++;
      }
      stateTo->sizeList.push_back( (*sizeIter) );
    }

    if ( sizeIter != stateFrom->sizeList.end() )
      sizeIter++;
  }

  sentStates[userId].push_back( stateTo );

  //write diff to data
  for ( i = 0; i<neededSize; i++ )
  {
    if ( i < stateFrom->dataLength )
      data[i] = stateTo->data[i] - stateFrom->data[i];
    else
      data[i] = stateTo->data[i];
  }

  return neededSize;
}

/**
 * sets a new state out of a diff created on another host
 * @param userId hostId of user who send me that diff
 * @param data pointer to diff
 * @param length length of diff
 * @param stateId id of current state
 * @param fromStateId id of the base state id
 * @return true on success
 */
bool Synchronizeable::setStateDiff( int userId, byte* data, int length, int stateId, int fromStateId )
{
  //make sure this user has his history
  if ( recvStates.size() <= userId )
    recvStates.resize( userId+1 );

  //create new state
  StateHistoryEntry * stateTo = new StateHistoryEntry();
  stateTo->stateId = stateId;
  stateTo->dataLength = length;
  stateTo->data = (byte*)malloc( length );

  //remove old states
  StateHistory::iterator it = recvStates[userId].begin();

  while ( it != recvStates[userId].end() && (*it)->stateId < fromStateId )
    it++;

  if ( it != recvStates[userId].begin() )
  {
    for ( StateHistory::iterator it2 = recvStates[userId].begin(); it2 != it; it2++ )
    {
      if ( (*it2)->data != NULL )
      {
        delete (*it2)->data;
        (*it2)->data = NULL;
      }
    }
    recvStates[userId].erase( recvStates[userId].begin(), it );
  }

  //find state to apply diff to
  StateHistoryEntry * stateFrom = NULL;

  it = recvStates[userId].begin();
  while ( it != recvStates[userId].end() && (*it)->stateId != fromStateId )
    it++;

  if ( it == recvStates[userId].end() )
  {
    StateHistoryEntry * initialEntry = new StateHistoryEntry();

    initialEntry->stateId = fromStateId;
    initialEntry->dataLength = 0;
    initialEntry->data = NULL;

    stateFrom = initialEntry;
  }
  else
    stateFrom = (*it);

  //apply diff
  for ( int i = 0; i<length; i++ )
  {
    if ( i < stateFrom->dataLength )
      stateTo->data[i] = stateFrom->data[i] + data[i];
    else
      stateTo->data[i] = data[i];
  }

  //add state to state history
  recvStates[userId].push_back( stateTo );

  int i = 0;

  for ( SyncVarList::iterator it = syncVarList.begin(); it != syncVarList.end(); it++ )
  {
    i += (*it)->readFromBuf( stateTo->data + i, stateTo->dataLength - i );
  }

  assert( i == length -1 );

  return length;
}

 /**
 * override this function to be notified on change
 * of your registred variables.
 * @param id id's which have changed
 */
void Synchronizeable::varChangeHandler( std::list<int> & id )
{
}

/**
 * registers a varable to be synchronized over network
 * @param var see src/lib/network/synchronizeable_var/ for available classes
 */
void Synchronizeable::registerVar( SynchronizeableVar * var )
{
  syncVarList.push_back( var );
}

/**
 * registers a varable to be synchronized over network
 * return value is passed to varChangeHandler on change
 * @param var see src/lib/network/synchronizeable_var/ for available classes
 * @return handle passed to varChangeHandler on changes
 */
int Synchronizeable::registerVarId( SynchronizeableVar * var )
{
  syncVarList.push_back( var );
  return syncVarList.size()-1;
}