/*
*   ORXONOX - the hottest 3D action shooter ever to exist
*
*
*   License notice:
*
*   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
*   of the License, or (at your option) any later version.
*
*   This program is distributed in the hope that it will be useful,
*   but WITHOUT ANY WARRANTY; without even the implied warranty of
*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*   GNU General Public License for more details.
*
*   You should have received a copy of the GNU General Public License
*   along with this program; if not, write to the Free Software
*   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*
*   Author:
*      ...
*   Co-authors:
*      ...
*
*/
#include <zlib.h>

#include "core/CoreIncludes.h"
#include "Synchronisable.h"
#include "GameStateClient.h"

namespace network
{
  GameStateClient::GameStateClient() {
  }

  GameStateClient::~GameStateClient() {
  }

  bool GameStateClient::pushGameState(GameStateCompressed *compstate) {
    if(compstate->diffed)
      return loadSnapshot(decode(reference, *compstate));
    else
      return loadSnapshot(decode(*compstate));
  }

  /**
  * This function removes a Synchronisable out of the universe
  * @param it iterator of the list pointing to the object
  * @return iterator pointing to the next object in the list
  */
  void GameStateClient::removeObject(orxonox::Iterator<Synchronisable> &it) {
    orxonox::Iterator<Synchronisable> temp=it;
    ++it;
    delete  *temp;
  }

  /**
  * This function loads a Snapshort of the gamestate into the universe
  * @param state a GameState struct containing the size of the gamestate and a pointer linking to a flat list (returned by getSnapshot)
  */
  bool GameStateClient::loadSnapshot(GameState *state) {
    unsigned char *data=state->data;
    COUT(4) << "loadSnapshot: loading gs: " << state->id << std::endl;
    // get the start of the Synchronisable list
    orxonox::Iterator<Synchronisable> it=orxonox::ObjectList<Synchronisable>::start();
    syncData sync;
    // loop as long as we have some data ;)
    while(data < state->data+state->size){
      // prepare the syncData struct
      sync.length = (int)*data;
      data+=sizeof(int);
      sync.objectID = (int)*data;
      data+=sizeof(int);
      sync.classID = (int)*data;
      data+=sizeof(int);
      sync.data = data;
      data+=sync.length;

      if(it->objectID!=sync.objectID){
        // bad luck ;)
        // delete the synchronisable (obviously seems to be deleted on the server)
        while(it && it->objectID!=sync.objectID){
          removeObject(it);
        }
        if(!it){
          COUT(4) << "classid: " << sync.classID << ", name: " << ID(sync.classID)->getName() << std::endl;
          Synchronisable *no = (Synchronisable*)(ID(sync.classID)->fabricate());
          no->objectID=sync.objectID;
          no->classID=sync.classID;
          it=orxonox::ObjectList<Synchronisable>::end();
          // update data and create object/entity...
          if( !no->updateData(sync) && !no->create() )
            COUT(2) << "We couldn't create/update the object: " << sync.objectID << std::endl;
          ++it;
        }
      } else {
        // we have our object
        if(! it->updateData(sync))
          COUT(2) << "We couldn't update objectID: " \
          << sync.objectID << "; classID: " << sync.classID << std::endl;
      }
      ++it;
    }

    return true;
  }

  GameState *GameStateClient::diff(GameState a, GameState b) {
    unsigned char *ap = a.data, *bp = b.data;
    int of=0; // pointers offset
    int dest_length=0;
    if(a.size>=b.size)
      dest_length=a.size;
    else
      dest_length=b.size;
    unsigned char *dp = (unsigned char *)malloc(dest_length*sizeof(unsigned char));
    while(of<a.size && of<b.size){
      *(dp+of)=*(ap+of)^*(bp+of); // do the xor
      ++of;
    }
    if(a.size!=b.size){ // do we have to fill up ?
      unsigned char n=0;
      if(a.size<b.size){
        while(of<dest_length){
          *(dp+of)=n^*(bp+of);
          of++;
        }
      } else{
        while(of<dest_length){
          *(dp+of)=*(ap+of)^n;
          of++;
        }
      }
    }
    // should be finished now
    // FIXME: is it true or false now? (struct has changed, producing warnings)
    GameState *r = new GameState;
    r->id = b.id;
    r->size = dest_length;
    r->diffed = true;
    r->data = dp;
    return r;
  }

  GameState *GameStateClient::decompress(GameStateCompressed a) {
    int normsize = a.normsize;
    int compsize = a.compsize;
    int bufsize;
    if(normsize < compsize)
      bufsize = compsize;
    else
      bufsize = normsize;
    unsigned char* dest = (unsigned char*)malloc( bufsize );
    int retval;
    uLongf length=normsize;
    //std::cout << "gamestateclient" << std::endl;
    //std::cout << "normsize " << a.normsize << " compsize " << a.compsize << " " << bufsize << std::endl;
    retval = uncompress( dest, &length, a.data, (uLong)compsize );
    //std::cout << "length " << length << std::endl;
    switch ( retval ) {
      case Z_OK:
        COUT(3) << "successfully decompressed" << std::endl; break;
      case Z_MEM_ERROR: 
        COUT(1) << "not enough memory available" << std::endl;
        return NULL;
      case Z_BUF_ERROR: 
        COUT(2) << "not enough memory available in the buffer" << std::endl;
        return NULL;
      case Z_DATA_ERROR: 
        COUT(2) << "data corrupted" << std::endl;
        return NULL;
    }

    GameState *gamestate = new GameState;
    gamestate->id = a.id;
    gamestate->size = normsize;
    gamestate->data = dest;
    gamestate->diffed = a.diffed;

    free(a.data);
    
    return gamestate;
  }

  GameState *GameStateClient::decode(GameState a, GameStateCompressed x) {
    GameState *t = decompress(x);
    if(t==NULL)
      return NULL;
    else
      return diff(a, *t);
  }

  GameState *GameStateClient::decode(GameStateCompressed x) {
    GameState *t = decompress(x);
    if(t==NULL)
      return NULL;
    else
      return t;
  }

}