/*
 *   ORXONOX - the hottest 3D action shooter ever to exist
 *                    > www.orxonox.net <
 *
 *
 *   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:
 *      Oliver Scheuss, (C) 2007
 *   Co-authors:
 *      ...
 *
 */

//
// C++ Implementation: GameStateManager
//
// Description:
//
//
// Author:  Oliver Scheuss, (C) 2007
//
// Copyright: See COPYING file that comes with this distribution
//
//

#include "GameStateManager.h"

#include <utility>
#include <iostream>
#include <zlib.h>

#include "core/CoreIncludes.h"
#include "core/BaseObject.h"
#include "ClientInformation.h"
#include "Synchronisable.h"

namespace network
{
  GameStateManager::GameStateManager(ClientInformation *head) {
    id_=0;
    head_=head;
  }

  GameStateManager::~GameStateManager() {
  }

  void GameStateManager::update(){
    cleanup();
    reference = getSnapshot();
    COUT(4) << "inserting gamestate: " << reference << std::endl;
    gameStateMap.insert(std::pair<int, GameState*>(id_, reference));
    gameStateUsed[id_]=0;
    printGameStates();
    return;
  }
  
  
  /**
   * this function is used to keep the memory usage low
   * it tries to delete all the unused gamestates
   * 
   * 
   */
  void GameStateManager::cleanup(){
    std::map<int,int>::iterator it = gameStateUsed.begin();
    while(it!=gameStateUsed.end()){
      if((id_-(*it).first)<KEEP_GAMESTATES)
        break;
      if( (*it).second <= 0 ){
        COUT(4) << "GameStateManager: deleting gamestate with id: " << (*it).first << ", uses: " << (*it).second << std::endl;
        std::map<int, GameState *>::iterator tempit = gameStateMap.find((*it).first);
        if( tempit != gameStateMap.end() ){
          GameState *temp = tempit->second;
          if(temp){
            delete[] gameStateMap[(*it).first]->data;
            delete gameStateMap[(*it).first];
            gameStateMap.erase((*it).first);
          }
        }
        gameStateUsed.erase(it++);
        continue;
      }/*else if(id_-it->first<=KEEP_GAMESTATES){  //as soon as we got a used gamestate break here because we could use newer gamestates in future but only if we do not exceed KEEP_GAMESTATES # of gamestates in cache
        COUT(4) << "breaking " << std::endl;
        break;
      }*/
      it++;
    }
  }

  GameStateCompressed *GameStateManager::popGameState(int clientID) {
    //why are we searching the same client's gamestate id as we searched in
    //Server::sendGameState?
    int gID = head_->findClient(clientID)->getGamestateID();
    COUT(4) << "G.St.Man: popgamestate: sending gstate_id: " << id_ << " diffed from: " << gID << std::endl;
//     COUT(3) << "gamestatemap: " << &gameStateMap << std::endl;
    //chose wheather the next gamestate is the first or not
    if(gID != GAMESTATEID_INITIAL){
      // TODO something with the gamestatemap is wrong
      GameState *client=NULL;
      std::map<int, GameState*>::iterator it = gameStateMap.find(gID);
      if(it!=gameStateMap.end())
        client = it->second;
      GameState *server = reference;
      COUT(3) << "client: " << client << " server: " << server << " gamestatemap: " << &gameStateMap << std::endl;
      if(client)
        return encode(client, server);
      else
        return encode(server);
    } else {
      COUT(4) << "we got a GAMESTATEID_INITIAL for clientID: " << clientID << std::endl;
      GameState *server = reference;
//       ackGameState(clientID, reference->id);
      return encode(server);
      // return an undiffed gamestate and set appropriate flags
    }
  }
  
  bool GameStateManager::pushGameState( GameStateCompressed *gs, int clientID ){
    GameState *ugs = decompress(gs);
    delete[] gs->data;
    delete gs;
    bool result = loadPartialSnapshot(ugs, clientID);
    delete[] ugs->data;
    delete ugs;
    return result;
  }

  /**
  * This function goes through the whole list of synchronisables and
  * saves all the synchronisables to a flat "list".
  * @return struct of type gamestate containing the size of the whole gamestate and a pointer linking to the flat list
  */
  GameState *GameStateManager::getSnapshot()
  {
    //std::cout << "begin getSnapshot" << std::endl;
    //the size of the gamestate
    int totalsize=0;
    int memsize=0;
    //the size of one specific synchronisable
    int tempsize=0;
    // get the start of the Synchronisable list
    orxonox::Iterator<Synchronisable> it;
    // struct for return value of Synchronisable::getData()
    syncData sync;

    GameState *retval=new GameState; //return value
    retval->id=++id_;
    COUT(4) << "G.ST.Man: producing gamestate with id: " << retval->id << std::endl;
    // offset of memory functions
    int offset=0, size=0;
    // get total size of gamestate
    for(it = orxonox::ObjectList<Synchronisable>::start(); it; ++it){
      size+=it->getSize(); // size of the actual data of the synchronisable
      size+=3*sizeof(int); // size of datasize, classID and objectID
    }
    //retval->data = (unsigned char*)malloc(size);
    retval->data = new unsigned char[size];
    if(!retval->data){
      COUT(2) << "GameStateManager: could not allocate memory" << std::endl;
      return NULL;
    }
    memsize=size;
    // go through all Synchronisables
    for(it = orxonox::ObjectList<Synchronisable>::start(); it; ++it){
      //get size of the synchronisable
      tempsize=it->getSize();
      // add place for data and 3 ints (length,classid,objectid)
      totalsize+=tempsize+3*sizeof(int);
      // allocate+tempsize additional space
      if(totalsize > size){
        COUT(3) << "G.St.Man: need additional memory" << std::endl;
//         if(tempsize < 1000){
//           retval->data = (unsigned char *)realloc((void *)retval->data, totalsize+1000);
//           memsize+=1000;
//         } else {
//           retval->data = (unsigned char *)realloc((void *)retval->data, totalsize+1000);
//           memsize+=tempsize+1000;
//         }
//         COUT(5) << "G.St.Man: additional space allocation finished" << std::endl;
      }

      // run Synchronisable::getData with offset and additional place for 3 ints in between (for ids and length)
      sync=it->getData((retval->data)+offset+3*sizeof(int));
      memcpy(retval->data+offset, (void *)&(sync.length), sizeof(int));
      memcpy(retval->data+offset+sizeof(int), (void *)&(sync.objectID), sizeof(int));
      memcpy(retval->data+offset+2*sizeof(int), (void *)&(sync.classID), sizeof(int));
      // increase data pointer
      offset+=tempsize+3*sizeof(int);
    }
    retval->size=totalsize;
    //#### bugfix
    retval->diffed = false;
    retval->complete = true;
    //std::cout << "end snapShot" << std::endl;
    COUT(5) << "G.ST.Man: Gamestate size: " << totalsize << std::endl;
    COUT(5) << "G.ST.Man: 'estimated' Gamestate size: " << size << std::endl;
    return retval;
  }

  bool GameStateManager::loadPartialSnapshot(GameState *state, int clientID){
    if(!state)
      return false;
    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;
    /*ClientInformation *client = head_->findClient(clientID);
    if(client)
      if(client->getPartialGamestateID()>state->id){
        COUT(3) << "we received an obsolete partial gamestate" << std::endl;
        return false;
      }
    else;*/
        //what should we do now ??
    // 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;
      COUT(4) << "objectID: " << sync.objectID << " classID: " << sync.classID << std::endl;
      while(it && it->objectID!=sync.objectID)
        ++it;


      if(!it){
        // the object does not exist yet
        COUT(4) << "loadsnapshot: creating new object " << std::endl;
        //COUT(4) << "loadSnapshot:\tclassid: " << sync.classID << ", name: " << ID((unsigned int) sync.classID)->getName() << std::endl;
        orxonox::Identifier* id = ID((unsigned int)sync.classID);
        if(!id){
          COUT(4) << "We could not identify a new object; classid: " << sync.classID << std::endl;
          continue;
        }
        Synchronisable *no = dynamic_cast<Synchronisable *>(id->fabricate());
        COUT(4) << "loadpartialsnapshot (generating new object): classid: " << sync.classID << " objectID: " << sync.objectID << " length: " << sync.length << std::endl;
        no->objectID=sync.objectID;
        no->classID=sync.classID;
        it=orxonox::ObjectList<Synchronisable>::end();
        // update data and create object/entity...
        if( !no->updateData(sync) )
          COUT(1) << "We couldn't update the object: " << sync.objectID << std::endl;
        if( !no->create() )
          COUT(1) << "We couldn't manifest (create() ) the object: " << sync.objectID << std::endl;
      }else{
        // we have our object
        COUT(4) << "loadpartialsnapshot: we found the appropriate object" << std::endl;
        if(checkAccess(clientID, sync.objectID)){
          if(! it->updateData(sync))
            COUT(1) << "We couldn't update objectID: " \
              << sync.objectID << "; classID: " << sync.classID << std::endl;
        }else
          COUT(4) << "loadPartialSnapshot: no access to change objectID: " << sync.objectID << std::endl;
      }
      ++it;
    }
    //client->setPartialGamestateID(state->id);
    return true;
  }
  
  
  //##### ADDED FOR TESTING PURPOSE #####
  GameStateCompressed* GameStateManager::testCompress( GameState* g ) {
    return compress_( g );
  }

  GameState* GameStateManager::testDiff( GameState* a, GameState* b ) {
    return diff( a, b );
  }
  //##### END TESTING PURPOSE #####

  GameStateCompressed *GameStateManager::encode(GameState *a, GameState *b) {
    COUT(4) << "G.St.Man: this will be a DIFFED gamestate" << std::endl;
    GameState *r = diff(a,b);
    GameStateCompressed *c = compress_(r);
    delete[] r->data;
    delete r;
    return c;
  }

  GameStateCompressed *GameStateManager::encode(GameState *a) {
    COUT(5) << "G.St.Man: encoding gamestate (compress)" << std::endl;
    a->base_id=GAMESTATEID_INITIAL;
    return compress_(a);
    /*GameStateCompressed *g = new GameStateCompressed;
    g->base_id = a->base_id;
    g->id = a->id;
    g->diffed = a->diffed;
    g->data = a->data;
    g->normsize = a->size;
    g->compsize = a->size;
    return g;*/
  }

  GameState *GameStateManager::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));
    unsigned char *dp = new unsigned char[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++;
        }
      }
    }

    GameState *r = new GameState;
    r->id = b->id;
    r->size = dest_length;
    r->diffed = true;
    r->base_id = a->id;
    r->data = dp;
    r->complete = true;
    return r;
  }

  GameStateCompressed *GameStateManager::compress_(GameState *a) {
    //COUT(4) << "G.St.Man: compressing gamestate" << std::endl;

    //COUT(4) << "G.St.Man: a: id: " << a->id << " base_id: " << a->base_id << " size: " << a->size << " diffed: " << a->diffed << std::endl;
    int size = a->size;

    uLongf buffer = (uLongf)((a->size + 12)*1.01)+1;
    //COUT(4) << "size: " << size << ", buffer: " << buffer << std::endl;
    //unsigned char* dest = (unsigned char*)malloc( buffer );
    unsigned char *dest = new unsigned char[buffer];
    //COUT(4) << "dest: " << dest << std::endl;
    int retval;
    //std::cout << "before ziped " << buffer << std::endl;
    retval = compress( dest, &buffer, a->data, (uLong)size );
    //COUT(4) << "bloablabla aft3er compress" << std::endl;
    //std::cout << "after ziped " << buffer << std::endl;

    switch ( retval ) {
      case Z_OK: COUT(5) << "G.St.Man: compress: successfully compressed" << std::endl; break;
      case Z_MEM_ERROR: COUT(1) << "G.St.Man: compress: not enough memory available in gamestate.compress" << std::endl; 
      return NULL;
      case Z_BUF_ERROR: COUT(2) << "G.St.Man: compress: not enough memory available in the buffer in gamestate.compress" << std::endl;
      return NULL;
      case Z_DATA_ERROR: COUT(2) << "G.St.Man: compress: data corrupted in gamestate.compress" << std::endl;
      return NULL;
    }

    GameStateCompressed *compressedGamestate = new GameStateCompressed;
    compressedGamestate->compsize = buffer;
//     std::cout << "compressedGamestate.compsize = buffer; " << buffer << std::endl;
    compressedGamestate->normsize = size;
//     std::cout << "compressedGamestate.normsize = size; " << size << std::endl;
    compressedGamestate->id = a->id;
    compressedGamestate->data = dest;
    compressedGamestate->diffed = a->diffed;
    compressedGamestate->complete = a->complete;
    compressedGamestate->base_id = a->base_id;
    //COUT(5) << "G.St.Man: saved compressed data in GameStateCompressed:" << std::endl;
    return compressedGamestate;
  }
  
  GameState *GameStateManager::decompress(GameStateCompressed *a) {
    //COUT(4) << "GameStateClient: uncompressing gamestate. id: " << a->id << ", baseid: " << a->base_id << ", normsize: " << a->normsize << ", compsize: " << a->compsize << std::endl;
    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 );
    unsigned char *dest = new unsigned char[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(5) << "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 (zlib)" << std::endl; return NULL;
    }

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


    return gamestate;
  }
  

  void GameStateManager::ackGameState(int clientID, int gamestateID) {
    ClientInformation *temp = head_->findClient(clientID);
    if(temp==0)
      return;
    int curid = temp->getGamestateID();
    if(curid > gamestateID)
      // the network packets got messed up 
      return;
    COUT(4) << "acking gamestate " << gamestateID << " for clientid: " << clientID << " curid: " << curid << std::endl;
    // decrease usage of gamestate and save it
//     deleteUnusedGameState(curid);
    //increase gamestateused
    if(curid!=GAMESTATEID_INITIAL)
      --(gameStateUsed.find(curid)->second);
    ++(gameStateUsed.find(gamestateID)->second);
    temp->setGamestateID(gamestateID);
    /*
    GameState *old = clientGameState[clientID];
    deleteUnusedGameState(old);
    clientGameState[clientID]=idGameState[gamestateID];*/
  }

  bool GameStateManager::printGameStates() {
    std::map<int, GameState*>::iterator it;
    COUT(4) << "gamestates: ";
    for(it = gameStateMap.begin(); it!=gameStateMap.end(); it++){
      COUT(4) << (*it).first << ":" << (*it).second << " | ";
    }
    COUT(4) << std::endl;
    return true;
  }
  
  bool GameStateManager::checkAccess(int clientID, int objectID){
    // currently we only check, wheter the object is the clients spaceship
//     return head_->findClient(objectID)->getShipID()==objectID;
    return true; // TODO: change this
  }
  
  void GameStateManager::removeClient(ClientInformation* client){
    if(!client)
      return;
    if(client->getGamestateID()>=0)
      gameStateUsed[client->getGamestateID()]--;
    head_->removeClient(client->getID());
  }

}