/*
 *   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 "ClientInformation.h"
#include "Synchronisable.h"

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

  GameStateManager::~GameStateManager() {
  }

  void GameStateManager::update(){
    cleanup();
    reference = getSnapshot(id);
    gameStateMap.insert(std::pair<int, GameState*>(id, reference));
    gameStateUsed[id]=0;
    ++id;
    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( (*it).second <= 0 ){
        free(gameStateMap[(*it).first]->data);
        delete gameStateMap[(*it).first];
        gameStateMap.erase((*it).first);
        gameStateUsed.erase(it++);
      }else  //as soon as we got a used gamestate break here because we could use newer gamestates in future
        break;
    }
  }

  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 << " (not diffed yet)" << std::endl;
    
    //chose wheather the next gamestate is the first or not
    if(gID != GAMESTATEID_INITIAL){
      GameState *client = gameStateMap[gID];
      GameState *server = reference;
      //head_->findClient(clientID)->setGamestateID(id);
      return encode(client, server);
    } else {
      GameState *server = reference;
      //head_->findClient(clientID)->setGamestateID(id);
      return encode(server);
      // return an undiffed gamestate and set appropriate flags
    }
  }

  /**
  * 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(int id)
  {
    //std::cout << "begin getSnapshot" << std::endl;
    //the size of the gamestate
    int totalsize=0;
    int memsize=1000;
    //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;
    // reserve a little memory and increase it later on
    COUT(5) << "G.ST.Man: mallocing: " << memsize << std::endl;
    retval->data = (unsigned char*)malloc(memsize);
    COUT(5) << "G.ST.Man: malloced: " << memsize << std::endl;

    // offset of memory functions
    int offset=0;
    // go through all Synchronisables
    for(it = orxonox::ObjectList<Synchronisable>::start(); it; ++it){
      //std::cout << "begin inner loop" << std::endl;
      //std::cout << "gamestatemanager: in for loop" << std::endl;
      //get size of the synchronisable
      tempsize=it->getSize();
      //COUT(5) << "size of temp gamestate: " << tempsize << std::endl;
      //COUT(2) << "size of synchronisable: " << tempsize << std::endl;
      // add place for data and 3 ints (length,classid,objectid)
      totalsize+=tempsize+3*sizeof(int);
      //std::cout << "totalsize: " << totalsize << std::endl;
      //COUT(5) << "G.St.Man: current totalsize=" << totalsize << std::endl;
      //COUT(5) << "G.St.Man: current it->classID=" << it->classID << " it->objectID=" << it->objectID << std::endl;
      // allocate additional space
      if((totalsize+tempsize) > memsize){
        COUT(5) << "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));
      //*(retval->data+offset)=sync.length;
      memcpy(retval->data+offset+sizeof(int), (void *)&sync.objectID, sizeof(int));
      //*(retval->data+offset+sizeof(int))=sync.objectID;
      memcpy(retval->data+offset+2*sizeof(int), (void *)&sync.classID, sizeof(int));
      //*(retval->data+offset+2*sizeof(int))=sync.classID;
      // increase data pointer
      offset+=tempsize+3*sizeof(int);
      //std::cout << "end inner loop" << std::endl;
    }
    retval->size=totalsize;
    //#### bugfix
    retval->diffed = false;
    //std::cout << "end snapShot" << std::endl;
    COUT(5) << "G.ST.Man: Gamestate size: " << totalsize << std::endl;
    return retval;
  }

  //##### 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(5) << "G.St.Man: this will be a DIFFED gamestate" << std::endl;
    //GameState r = diff(a,b);
    //r.diffed = true;
    GameState *r = b;
    r->diffed = false;
    //return compress_(r);
    GameStateCompressed *g = new GameStateCompressed;
    g->base_id = b->base_id;
    g->id = b->id;
    g->diffed = b->diffed;
    g->data = b->data;
    g->normsize = b->size;
    g->compsize = b->size;
    return g;
  }

  GameStateCompressed *GameStateManager::encode(GameState *a) {
    COUT(5) << "G.St.Man: this will be a not diffed gamestate" << std::endl;
    a->diffed=false;
    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));
    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;
    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 );
    //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->base_id = a->base_id;
    //COUT(5) << "G.St.Man: saved compressed data in GameStateCompressed:" << std::endl;
    return compressedGamestate;
  }

  void GameStateManager::ackGameState(int clientID, int gamestateID) {
    ClientInformation *temp = head_->findClient(clientID);
    int curid = temp->getID();
    // decrease usage of gamestate and save it
    deleteUnusedGameState(curid);
    //increase gamestateused
    ++gameStateUsed.find(gamestateID)->second;
    temp->setGamestateID(gamestateID);
    /*
    GameState *old = clientGameState[clientID];
    deleteUnusedGameState(old);
    clientGameState[clientID]=idGameState[gamestateID];*/
  }

  bool GameStateManager::deleteUnusedGameState(int gamestateID) {
    int used = --(gameStateUsed.find(gamestateID)->second);
    if(id-gamestateID>KEEP_GAMESTATES && used==0){
      // delete gamestate
      delete gameStateMap.find(gamestateID)->second;
      gameStateMap.erase(gamestateID);
      return true;
    }
    return false;
  }

}