/*
   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: ...
   co-programmer: ...
*/

#define DEBUG_SPECIAL_MODULE DEBUG_MODULE_PARTICLE

#include "particle_engine.h"

#include "particle_system.h"
#include "particle_emitter.h"

#include "list.h"
#include "debug.h"
#include "stdlibincl.h"
#include "load_param.h"

using namespace std;

/**
 *  standard constructor
*/
ParticleEngine::ParticleEngine ()
{
   this->setClassID(CL_PARTICLE_ENGINE, "ParticleEngine");
   this->setName("ParticleEngine");

   this->systemList = new tList<ParticleSystem>;
   this->emitterList = new tList<ParticleEmitter>;
   this->connectionList = new tList<ParticleConnection>;
}

/**
 *  the singleton reference to this class
*/
ParticleEngine* ParticleEngine::singletonRef = NULL;

/**
 *  deletes all the system, emitters, connections and Lists
*/
ParticleEngine::~ParticleEngine ()
{
  // delete all remaining systems
  tIterator<ParticleSystem>* sysIt = this->systemList->getIterator();
  ParticleSystem* tmpSys = sysIt->nextElement();
  while(tmpSys)
    {
      delete tmpSys;
      tmpSys = sysIt->nextElement();
    }
  delete sysIt;
  delete this->systemList;

  // delete all remaining emitters
  tIterator<ParticleEmitter>* emitIt = this->emitterList->getIterator();
  ParticleEmitter* tmpEmit = emitIt->nextElement();
  while(tmpEmit)
    {
      delete tmpEmit;
      tmpEmit = emitIt->nextElement();
    }
  delete emitIt;
  delete this->emitterList;

  // there should be no more Connections
  if (this->connectionList->getSize() == 0)
    delete this->connectionList;
  else
    PRINTF(2)("The Connection List is not empty. This should not happen.\n");

  ParticleEngine::singletonRef = NULL;
}

/**
  \brief loads the ParticleEngines settings and connections between particles and emitters
* @param root the XML-element to load this from.
 */
void ParticleEngine::loadParams(const TiXmlElement* root)
{
  const TiXmlElement* element = root->FirstChildElement();
  while( element != NULL)
  {
    LoadParam<ParticleEngine>(element, "connect", this, &ParticleEngine::addConnection, true)
        .describe("connects an Emitter to a System (emitterName, systemName)");
    element = element->NextSiblingElement();
  }
}

/**
 *  Adds a System to the System list.

   this is done automatically when creating a ParticleSystem
*/
void ParticleEngine::addSystem(ParticleSystem* system)
{
  this->systemList->add(system);
}

/**
 *  Adds an emitter to the emitterList

   this is done automatically when creating a ParticleEmitter
*/
void ParticleEngine::addEmitter(ParticleEmitter* emitter)
{
  this->emitterList->add(emitter);
}

/**
  \brief Connects a ParticleSystem to a ParticleSystem thus emitting Particles.
* @param emitter the Emitter to connect to the System
* @param system the System to connect to the Emitter
*/
void ParticleEngine::addConnection(const char* emitter, const char* system)
{
  ParticleEmitter* tmpEmit = this->getEmitterByName(emitter);
  ParticleSystem* tmpSys = this->getSystemByName(system);

  if (tmpEmit != NULL && tmpSys != NULL)
    this->addConnection(tmpEmit, tmpSys);
  else
  {
    if (tmpEmit == NULL)
      PRINTF(2)("Emitter %s not found in the List of emitters, not connecting to %s\n", emitter, system);
    if (tmpEmit == NULL)
      PRINTF(2)("System %s not found in the List of emitters, not connecting to %s\n", system, emitter);
  }
}

/**
 *  Connects a ParticleSystem to a ParticleSystem thus emitting Particles.
 * @param emitter the Emitter to connect to the System
 * @param system the System to connect to the Emitter
*/
void ParticleEngine::addConnection(ParticleEmitter* emitter, ParticleSystem* system)
{
  // look, if we have already added this connection
  tIterator<ParticleConnection>* tmpConIt = connectionList->getIterator();
  ParticleConnection* tmpConnection = tmpConIt->nextElement();
  while(tmpConnection)
    {
      if (tmpConnection->emitter == emitter && tmpConnection->system == system)
        {
          PRINTF(2)("Connection between Emitter and System already added\n");
          delete tmpConIt;
          return;
        }

      tmpConnection = tmpConIt->nextElement();
    }
  delete tmpConIt;



  ParticleConnection* tmpCon = new ParticleConnection;
  tmpCon->emitter = emitter;
  tmpCon->system = system;

  this->connectionList->add(tmpCon);
}

/**
 *  Removes a system from the systemList and also removes all Connections to the System
 * @param system The ParticleSystem to delete
*/
bool ParticleEngine::removeSystem(ParticleSystem* system)
{
  // remove any connections, that have this system within
  tIterator<ParticleConnection>* tmpConIt = connectionList->getIterator();
  ParticleConnection* tmpConnection = tmpConIt->nextElement();
  while(tmpConnection)
    {
      if (tmpConnection->system == system)
        this->breakConnection(tmpConnection);
      tmpConnection = tmpConIt->nextElement();
    }
  delete tmpConIt;

  // remove the System from the systemList.
  this->systemList->remove(system);
}

/**
 *  removes an emitter from the emitterList and also from all Connections it is attached to.
 * @param emitter the ParticleEmitter to remove.
*/
bool ParticleEngine::removeEmitter(ParticleEmitter* emitter)
{
  // remove any connections, that have this emitter within
  tIterator<ParticleConnection>* tmpConIt = connectionList->getIterator();
  ParticleConnection* tmpConnection = tmpConIt->nextElement();
  while(tmpConnection)
    {
      if (tmpConnection->emitter == emitter)
        this->breakConnection(tmpConnection);
      tmpConnection = tmpConIt->nextElement();
    }
  delete tmpConIt;

  // remove the emitter from the emitterList
  this->emitterList->remove(emitter);
}

/**
 *  removes a Connection between an Emitter and a System
 * @param emitter The emitter of the connection to remove
 * @param system The system of the connection to remove
 * @returns true, if the connection was broken, false if the conntection was not found

   only if both system and emitter are in the connection the Connection will be broken
*/
bool ParticleEngine::breakConnection(ParticleEmitter* emitter, ParticleSystem* system)
{
  // look, if we have already added this connection
  tIterator<ParticleConnection>* tmpConIt = connectionList->getIterator();
  ParticleConnection* tmpConnection = tmpConIt->nextElement();
  while(tmpConnection)
    {
    if (tmpConnection->emitter == emitter && tmpConnection->system == system)
      {
        this->breakConnection(tmpConnection);
        delete tmpConIt;
        return true;
      }
    tmpConnection = tmpConIt->nextElement();
    }
  delete tmpConIt;
  return false;
}

/**
 *  removes a Connection between an Emitter and a System
 * @param connection the connection to remove

   \see bool ParticleEngine::breakConnection(ParticleEmitter* emitter, ParticleSystem* system)
*/
bool ParticleEngine::breakConnection(ParticleConnection* connection)
{
  this->connectionList->remove(connection);
  return true;
}


/**
 *  this function ticks all the ParticleSystems, so an animation will flow
 * @param dt passed since last tick
*/
void ParticleEngine::tick(float dt)
{
  // ticks all the ParticleSystems
  tIterator<ParticleSystem>* tmpIt = systemList->getIterator();
  ParticleSystem* tmpSys = tmpIt->nextElement();
  while(tmpSys)
    {
      tmpSys->tick(dt);
      tmpSys = tmpIt->nextElement();
    }
  delete tmpIt;

  // add new Particles to each System connected to an Emitter.
  tIterator<ParticleConnection>* tmpConIt = connectionList->getIterator();
  ParticleConnection* tmpConnection = tmpConIt->nextElement();
  while(tmpConnection)
    {
      tmpConnection->emitter->tick(dt, tmpConnection->system);
      tmpConnection = tmpConIt->nextElement();
    }
  delete tmpConIt;
}

/**
 *  draws all the systems and their Particles.
*/
void ParticleEngine::draw() const
{
  tIterator<ParticleSystem>* tmpIt = systemList->getIterator();
  ParticleSystem* tmpSys = tmpIt->nextElement();
  while(tmpSys)
    {
      tmpSys->draw();
      tmpSys = tmpIt->nextElement();
    }
  delete tmpIt;

}

/**
 * @param systemName the name of the system to search for
 * @returns the system called by systemName or NULL if not found
*/
ParticleSystem* ParticleEngine::getSystemByName(const char* systemName) const
{
  tIterator<ParticleSystem>* tmpIt = systemList->getIterator();
  ParticleSystem* tmpSys = tmpIt->nextElement();
  while(tmpSys)
    {
      if (!strcmp(systemName, tmpSys->getName()))
        {
          delete tmpIt;
          return tmpSys;
        }
      tmpSys = tmpIt->nextElement();
    }
  delete tmpIt;
  return NULL;
}

/**
 * @param number the n-th system to return
 * @returns the system called by number or NULL if not found
*/
ParticleSystem* ParticleEngine::getSystemByNumber(unsigned int number) const
{
  int count = 0;
  tIterator<ParticleSystem>* tmpIt = systemList->getIterator();
  ParticleSystem* tmpSys = tmpIt->nextElement();
  while(tmpSys)
    {
      count++;
      if ( count == number)
        {
          delete tmpIt;
          return tmpSys;
        }
      tmpSys = tmpIt->nextElement();
    }
  delete tmpIt;
  return NULL;
}

/**
 * @param emitterName the name of the emitter to search for
 * @returns the emitter called by emitterName or NULL if not found
*/
ParticleEmitter* ParticleEngine::getEmitterByName(const char* emitterName) const
{
  tIterator<ParticleEmitter>* tmpIt = emitterList->getIterator();
  ParticleEmitter* tmpEmit = tmpIt->nextElement();
  while(tmpEmit)
    {
      if (!strcmp(emitterName, tmpEmit->getName()))
        {
          delete tmpIt;
          return tmpEmit;
        }
      tmpEmit = tmpIt->nextElement();
    }
  delete tmpIt;
  return NULL;
}


/**
 * @param number the n-th emitter to return
 * @returns the emitter called by number or NULL if not found
*/
ParticleEmitter* ParticleEngine::getEmitterByNumber(unsigned int number) const
{
  int count = 0;
  tIterator<ParticleEmitter>* tmpIt = emitterList->getIterator();
  ParticleEmitter* tmpEmit = tmpIt->nextElement();
  while(tmpEmit)
    {
      count++;
      if ( count == number)
        {
          delete tmpIt;
          return tmpEmit;
        }
      tmpEmit = tmpIt->nextElement();
    }
  delete tmpIt;
  return NULL;
}

/**
 *  outputs some nice debug information
*/
void ParticleEngine::debug()
{
  PRINT(0)("+-----------------------------------+\n");
  PRINT(0)("+ PARTICLE-ENGINE DEBUG INFORMATION +\n");
  PRINT(0)("+-----------------------------------+\n");
  PRINT(0)(" Reference: %p\n", ParticleEngine::singletonRef);
  PRINT(0)(" Count: Emitters: %d; Systems: %d, Connections: %d\n",
  this->emitterList->getSize(), this->systemList->getSize(), this->connectionList->getSize());

  if (this->connectionList->getSize() > 0)
  {
    PRINT(0)(" Connections:\n");
    PRINT(0)(" -----------------------------------\n");

    tIterator<ParticleConnection>* tmpConIt = connectionList->getIterator();
    ParticleConnection* tmpConnection = tmpConIt->nextElement();
    while(tmpConnection)
    {
      PRINT(0)(" Emitter '%s' emitts into System '%s'\n", tmpConnection->emitter->getName(), tmpConnection->system->getName());
      tmpConnection = tmpConIt->nextElement();
    }
    delete tmpConIt;
  }

  if (this->systemList->getSize() > 0)
  {
    tIterator<ParticleSystem>* tmpIt = systemList->getIterator();
    ParticleSystem* tmpSys = tmpIt->nextElement();
    while(tmpSys)
    {
      tmpSys->debug();
      tmpSys = tmpIt->nextElement();
    }
    delete tmpIt;
  }
  else
  {
    PRINT(0)("NO SYSTEMS\n");
  }
  if (this->emitterList->getSize() > 0)
  {
    tIterator<ParticleEmitter>* tmpIt = emitterList->getIterator();
    ParticleEmitter* tmpEmit = tmpIt->nextElement();
    while(tmpEmit)
    {
      tmpEmit->debug();
      tmpEmit = tmpIt->nextElement();
    }
    delete tmpIt;
  }
  else
  {
    PRINTF(0)("NO EMITTERS\n");
  }

  PRINT(0)("+--------------------------------PE-+\n");

}