/* 
   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: Patrick Boenzli
   co-programmer: Christian Meyer
*/

#include "world.h"
#include "world_entity.h"
#include "collision.h"
#include "track.h"
#include "player.h"
#include "command_node.h"
#include "camera.h"

using namespace std;


/** 
    \brief create a new World
    
    This creates a new empty world!
*/
World::World (char* name)
{
  this->worldName = name;
  this->debugWorldNr = -1;
  this->entities = new List<WorldEntity>();
}

World::World (int worldID)
{
  this->debugWorldNr = worldID;
  this->worldName = NULL;
  this->entities = new List<WorldEntity>();
}

/** 
    \brief remove the World from memory
*/
World::~World ()
{
  Orxonox *orx = Orxonox::getInstance();
  orx->get_localinput()->unbind (this->localPlayer);
  delete this->entities;
  delete this->localCamera;
}


/** 
    \brief initialize the world before use.
*/
Error World::init()
{
  this->bPause = false;
}

Error World::start()
{
  this->mainLoop();
}

Error World::stop()
{
  this->bQuitCurrentGame = true;
  this->localCamera->setWorld(NULL);
  this->~World();
}

Error World::pause()
{
  this->isPaused = true;
}

Error World::resume()
{
  this->isPaused = false;
}

void World::load()
{
  if(this->debugWorldNr != -1)
    {
      switch(this->debugWorldNr)
	{
	case DEBUG_WORLD_0:
	  {
	    // create some path nodes
	    this->pathnodes = new Vector[6];
	    this->pathnodes[0] = Vector(0, 0, 0);
	    this->pathnodes[1] = Vector(-100, 40, 0);
	    this->pathnodes[2] = Vector(-100, 140, 0);
	    this->pathnodes[3] = Vector(0, 180, 0);
	    this->pathnodes[4] = Vector(100, 140, 0);
	    this->pathnodes[5] = Vector(100, 40, 0);
	    
	    // create the tracks
	    this->tracklen = 6;
	    this->track = new Track[6];
	    for( int i = 0; i < this->tracklen; i++)
	      {
		this->track[i] = Track( i, (i+1)%this->tracklen, &this->pathnodes[i], &this->pathnodes[(i+1)%this->tracklen]);
	      }
	    
	    // create a player
	    //WorldEntity* myPlayer = (WorldEntity*) this->spawn<Player>();
	    WorldEntity* myPlayer = new Player();
	    this->spawn(myPlayer);
	    this->localPlayer = myPlayer;	    

	    // bind input
	    Orxonox *orx = Orxonox::getInstance();
	    orx->get_localinput()->bind (myPlayer);
	    
	    // bind camera
	    this->localCamera = new Camera(this);
	    this->getCamera()->bind (myPlayer);	
	    break;
	  }
	case DEBUG_WORLD_1:
	  {
	    // create some path nodes
	    this->pathnodes = new Vector[6];
	    this->pathnodes[0] = Vector(0, 0, 0);
	    this->pathnodes[1] = Vector(20, 10, 10);
	    this->pathnodes[2] = Vector(40, 0, 10);
	    this->pathnodes[3] = Vector(60, 10, 0);
	    this->pathnodes[4] = Vector(80, 20, 10);
	    this->pathnodes[5] = Vector(30, 50, 0);
	    
	    // create the tracks
	    this->tracklen = 6;
	    this->track = new Track[6];
	    for( int i = 0; i < this->tracklen; i++)
	      {
		this->track[i] = Track( i, (i+1)%this->tracklen, &this->pathnodes[i], &this->pathnodes[(i+1)%this->tracklen]);
	      }
	    
	    // create a player
	    //WorldEntity* myPlayer = (WorldEntity*) this->spawn<Player>();
	    WorldEntity* myPlayer = new Player();
	    this->spawn(myPlayer);
	    this->localPlayer = myPlayer;
	    
	    // bind input
	    Orxonox *orx = Orxonox::getInstance();
	    orx->get_localinput()->bind (myPlayer);
	    
	    // bind camera
	    this->localCamera = new Camera(this);
	    this->getCamera()->bind (myPlayer);	
	    break;
	  }
	default:
	  printf("World::load() - no world with ID %i found", this->debugWorldNr );
	}
    }
  else if(this->worldName != NULL)
    {

    }
}


/** 
    \brief checks for collisions
    
    This method runs through all WorldEntities known to the world and checks for collisions 
    between them. In case of collisions the collide() method of the corresponding entities 
    is called.
*/
void World::collide ()
{
  List<WorldEntity> *a, *b;
  WorldEntity *aobj, *bobj;
  
  a = entities->get_next();
  
  while( a != NULL)
    {
      aobj = a->get_object();
      if( aobj->bCollide && aobj->collisioncluster != NULL)
	{
	  b = a->get_next();
	  while( b != NULL )
	    {
	      bobj = b->get_object();
	      if( bobj->bCollide && bobj->collisioncluster != NULL )
		{
		  unsigned long ahitflg, bhitflg;
		  if( check_collision ( &aobj->place, aobj->collisioncluster, 
					&ahitflg, &bobj->place, bobj->collisioncluster, 
					&bhitflg) );
		  {
		    aobj->collide (bobj, ahitflg, bhitflg);
		    bobj->collide (aobj, bhitflg, ahitflg);
		  }
		}
	      b = b->get_next();
	    }
	}
      a = a->get_next();
    }
}

/** 
    \brief runs through all entities calling their draw() methods
*/
void World::draw ()
{
  // draw geometry
  
  // draw entities
  List<WorldEntity> *l;
  WorldEntity* entity;
  
  l = entities->get_next();  
  while( l != NULL ) 
    { 
      entity = l->get_object();
      if( entity->bDraw ) entity->draw();
      l = l->get_next();
    }
  
  
  // draw debug coord system
  glLoadIdentity();
  

  glBegin(GL_LINES);
  
  for( float x = -128.0; x < 128.0; x += 25.0)
    {
      for( float y = -128.0; y < 128.0; y += 25.0)
	{
	  glColor3f(1,0,0);
	  glVertex3f(x,y,-128.0);
	  glVertex3f(x,y,0.0);
	  glColor3f(0.5,0,0);
	  glVertex3f(x,y,0.0);
	  glVertex3f(x,y,128.0);
	}
    }
  for( float y = -128.0; y < 128.0; y += 25.0)
    {
      for( float z = -128.0; z < 128.0; z += 25.0)
	{
	  glColor3f(0,1,0);
	  glVertex3f(-128.0,y,z);
	  glVertex3f(0.0,y,z);
	  glColor3f(0,0.5,0);
	  glVertex3f(0.0,y,z);
	  glVertex3f(128.0,y,z);
	}
    }
  for( float x = -128.0; x < 128.0; x += 25.0)
    {
      for( float z = -128.0; z < 128.0; z += 25.0)
	{
	  glColor3f(0,0,1);
	  glVertex3f(x,-128.0,z);
	  glVertex3f(x,0.0,z);
	  glColor3f(0,0,0.5);
	  glVertex3f(x,0.0,z);
	  glVertex3f(x,128.0,z);
	}
      
    }
  
  //draw track
  glColor3f(0,1,1);
  for( int i = 0; i < tracklen; i++)
    {
      glVertex3f(pathnodes[i].x,pathnodes[i].y,pathnodes[i].z);
      glVertex3f(pathnodes[(i+1)%tracklen].x,pathnodes[(i+1)%tracklen].y,pathnodes[(i+1)%tracklen].z);
    }
  glEnd();
}

/** 
    \brief updates Placements and notifies entities when they left the 
    world
    
    This runs trough all WorldEntities and maps Locations to Placements 
    if they are bound, checks whether they left the level boundaries 
    and calls appropriate functions.
*/
void World::update ()
{
  List<WorldEntity> *l;
  WorldEntity* entity;
  Location* loc;
  Placement* plc;
  Uint32 t;
  
  l = entities->get_next();  
  while( l != NULL ) 
    { 
      entity = l->get_object();
      
      if( !entity->isFree() )
	{
	  loc = entity->get_location();
	  plc = entity->get_placement();
	  t = loc->part;
	  
	  /* check if entity has still a legal track-id */
	  if( t >= tracklen )
	    {
	      printf("An entity is out of the game area\n");
	      entity->left_world ();
	    }
	  else
	    {
	      while( track[t].map_coords( loc, plc) )
		{
		  track[t].post_leave (entity);
		  if( loc->part >= tracklen )
		    {
		      printf("An entity has left the game area\n");
		      entity->left_world ();
		      break;
		    }
		  track[loc->part].post_enter (entity);
		}
	    }
	}
      else
	{
	  /* TO DO: implement check whether this particular free entity 
	     is out of the game area
	     TO DO: call function to notify the entity that it left 
	     the game area
	  */
	}
      
      l = l->get_next();
    }
  
}

/** 
    \brief relays the passed time since the last frame to entities and Track parts
    \param deltaT: the time passed since the last frame in milliseconds
*/
void World::time_slice (Uint32 deltaT)
{
  List<WorldEntity> *l;
  WorldEntity* entity;
  float seconds = deltaT;
  
  seconds /= 1000;
  
  l = entities->get_next();  
  while( l != NULL) 
    { 
      entity = l->get_object();
      entity->tick (seconds);
      l = l->get_next();
    }
  
  for( int i = 0; i < tracklen; i++) track[i].tick (seconds);
}

/**
   \brief removes level data from memory
*/
void World::unload()
{
  if( pathnodes) delete []pathnodes;
  if( track) delete []pathnodes;
}



/**
   \brief calls the correct mapping function to convert a given "look at"-Location to a 
   Camera Placement
*/
void World::calc_camera_pos (Location* loc, Placement* plc)
{
  track[loc->part].map_camera (loc, plc);
}


void World::setTrackLen(Uint32 len)
{
  this->tracklen = len;
}

int World::getTrackLen()
{
  return this->tracklen;
}

void World::debug()
{
  List<WorldEntity> *l;
  WorldEntity* entity;
  
  printf("counting all entities\n");
  l = entities->get_next();  
  while( l != NULL ) 
    { 
      entity = l->get_object();
      if( entity->bDraw ) printf("got an entity\n");
      l = l->get_next();
    }
}


void World::mainLoop()
{
  this->lastFrame = SDL_GetTicks();
  this->bQuitOrxonox = false;
  this->bQuitCurrentGame = false;
  printf("World|Entering main loop\n");
  while(!this->bQuitOrxonox && !this->bQuitCurrentGame) /* pause pause pause ?!?!?*/
    {
      //debug routine
      //debug();
      // Network
      synchronize();
      // Process input
      handle_input();
      // Process time
      time_slice();
      // Process collision
      collision();
      // Draw
      display();
    }
  printf("World|Exiting the main loop\n");
}

/**
   \brief synchronize local data with remote data
*/
void World::synchronize ()
{
  // Get remote input
  // Update synchronizables
}

/**
   \brief run all input processing
*/
void World::handle_input ()
{
  // localinput
  Orxonox::getInstance()->get_localinput()->process();
  // remoteinput
}

/**
   \brief advance the timeline
*/
void World::time_slice ()
{
  Uint32 currentFrame = SDL_GetTicks();
  if(!this->bPause)
    {
      Uint32 dt = currentFrame - this->lastFrame;
      /*
      if(dt > 0)
	{
	  float fps = 1000/dt;
	  printf("fps = %f\n", fps);
	}
      else
	{
	  printf("fps = 1000\n");
	}
      */
      this->time_slice (dt);
      this->update ();
      this->localCamera->time_slice (dt);
    }
  this->lastFrame = currentFrame;
}

/**
   \brief compute collision detection
*/
void World::collision ()
{
  this->collide ();
}

/**
   \brief handle keyboard commands that are not meant for WorldEntities
   \param cmd: the command to handle
   \return true if the command was handled by the system or false if it may be passed to the WorldEntities
*/
bool World::system_command (Command* cmd)
{
  if( !strcmp( cmd->cmd, "quit"))
    {
      if( !cmd->bUp) this->bQuitOrxonox = true;
      return true;
    }
  return false;
}

/**
	\brief render the current frame
*/
void World::display ()
{
  // clear buffer
  glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
  // set camera
  this->localCamera->apply ();
  // draw world
  this->draw();
  // draw HUD
  // flip buffers
  SDL_GL_SwapBuffers();
}

Camera* World::getCamera()
{
  return this->localCamera;
}


void World::spawn(WorldEntity* entity)
{
  Location zeroloc;
  Location* loc = NULL;
  WorldEntity* owner;
  //T* entity = new T();
  entities->add (entity, LIST_ADD_NEXT);
  //if( loc == NULL)
  //{
      zeroloc.dist = 0;
      zeroloc.part = 0;
      zeroloc.pos = Vector();
      zeroloc.rot = Quaternion();
      loc = &zeroloc;
      //}
  entity->init (loc, owner);
  if (entity->bFree)
    {
      this->track[loc->part].map_coords( loc, entity->get_placement());
    }
  entity->post_spawn ();
  //return entity;
}