/*
   core/gameinterface.cc
   This file is part of the Osirion project and is distributed under
   the terms of the GNU General Public License version 2
*/

#include <stdlib.h>
#include <iostream>

#include "core/application.h"
#include "core/cvar.h"
#include "core/func.h"
#include "core/gameinterface.h"
#include "core/player.h"
#include "model/model.h"
#include "sys/sys.h"

namespace core
{

const float MIN_DELTA = 10e-10;

void func_list_model(std::string const &args)
{
	model::Model::list();
}

Player GameInterface::game_localplayer;

EntityControlable *localcontrol()
{ 
	if (game()->localplayer())
		return game()->localplayer()->control();
	else
		return 0;
	
}
Player *localplayer()
{ 
	return game()->localplayer();
}

GameInterface::GameInterface()
{
	clear();
	
	game_localplayer.clear();
	if (Cvar::sv_dedicated->value()) {
		game_localplayer.player_name.assign("Console");
	} else {
		game_localplayer.player_name.assign("Player");
		game_localplayer.update_info();
	}
	
	core::Func::add("list_model", (core::FuncPtr) func_list_model);
}

GameInterface::~GameInterface()
{
	core::Func::remove("list_model");

	game_localplayer.clear();

	clear();
}

// clear all game related objects
void GameInterface::clear()
{
	//con_debug << "Clearing game data\n";

	// remove all entities
	for (std::map<unsigned int, Entity*>::iterator it = Entity::registry.begin(); it != Entity::registry.end(); it++) {
		delete (*it).second;
	}
	Entity::registry.clear();

	// remove all game functions
	for (std::map<std::string, Func*>::iterator it = Func::registry.begin(); it != Func::registry.end(); it++) {
		if ( ((*it).second->flags() & Func::Game) == Func::Game) {
			delete (*it).second;
			Func::registry.erase(it);
		}
	}

	// remove all game cvars
	for (std::map<std::string, Cvar*>::iterator it = Cvar::registry.begin(); it != Cvar::registry.end(); it++) {
		if ( ((*it).second->flags() & Cvar::Game) == Cvar::Game) {
			delete (*it).second;
			Cvar::registry.erase(it);
		}
	}

	// remove all models
	model::Model::clear();

	game_previousframetime = 0;
	game_serverframetime = 0;
	game_clientframetime = 0;
}

void GameInterface::reset_clientstate(float timestamp, float prevtimestamp)
{
	game_previousframetime = prevtimestamp;
	game_serverframetime = timestamp;
	
	std::map<unsigned int, core::Entity *>::iterator it;
	for (it=core::Entity::registry.begin(); it != core::Entity::registry.end(); it++) {
		
		core::Entity *entity = (*it).second;

		if (entity->state() && !(entity->flags() & core::Entity::Static))
			entity->state()->assign(entity);
	}

	if ( game_clientframetime < game_previousframetime)
		game_clientframetime = game_previousframetime;
	else if ( game_clientframetime > game_serverframetime)
		game_clientframetime = game_serverframetime;

}


void GameInterface::update_entity_clientstate(Entity *entity)
{
	if (!entity->state()) {
		entity->entity_clientstate = new core::ClientState(entity);
		entity->entity_clientstate->assign(entity);
	}

	if(Cvar::cl_prediction->value() == 0) {

		entity->state()->assign(entity);
		return;
	}

	if (!(entity->flags() & core::Entity::Static)) {

		// clientstate location
		entity->state()->state_location = entity->state()->previouslocation() + 
		(entity->location() - entity->state()->previouslocation()) * timeoffset();

		if (game_clientframetime <= game_serverframetime) {
		
			entity->state()->state_axis.assign(entity->state()->previousaxis());

			float cosangle;		// cosine of an angle
			float angle;		// angle in radians	
			math::Vector3f n;	// normal of a plane

			n.assign(math::crossproduct( entity->state()->axis().forward(), entity->axis().forward()));
			if (!(n.length() < MIN_DELTA)) {
				n.normalize();
				cosangle = math::dotproduct( entity->state()->axis().forward(),  entity->axis().forward());
				angle = acos(cosangle) * timeoffset(); // * 180.0f / M_PI;
				if (angle > MIN_DELTA)
					entity->state()->state_axis.rotate(n, -angle);
			}

			n.assign(math::crossproduct( entity->state()->axis().left(), entity->axis().left()));
			if (!(n.length() < MIN_DELTA)) {
				n.normalize();
				cosangle = math::dotproduct( entity->state()->axis().left(), entity->axis().left());
				angle = acos(cosangle) * timeoffset(); // * 180.0f / M_PI;
				if (angle > MIN_DELTA)
					entity->state()->state_axis.rotate(n, -angle);
			}

			n.assign(math::crossproduct( entity->state()->axis().up(), entity->axis().up()));
			if (!(n.length() < MIN_DELTA)) {
				n.normalize();
				cosangle = math::dotproduct( entity->state()->axis().up(), entity->axis().up());
				angle = acos(cosangle) * timeoffset(); // * 180.0f / M_PI;
				if (angle > MIN_DELTA)
					entity->state()->state_axis.rotate(n, -angle);
			} 

		} else {
			entity->state()->state_axis.assign(entity->axis());
		}
	
	} else {
		entity->state()->assign(entity);
	}
}

void GameInterface::update_clientstate(float seconds)
{
	game_clientframetime += seconds;

	std::map<unsigned int, core::Entity *>::iterator it;
	for (it=core::Entity::registry.begin(); it != core::Entity::registry.end(); it++) {
		update_entity_clientstate((*it).second);
	}
}

float GameInterface::timeoffset() {

	if (game_clientframetime > game_serverframetime)
		return 1;

	float d = game_serverframetime - game_previousframetime;
	if (d <= 0)
		return 0;

	float t = game_clientframetime - game_previousframetime;
	return t/d;
}

}