#include <stdio.h>
#include <stdlib.h>
extern "C" {
  #include <lua.h>
  #include <lauxlib.h>
  #include <lualib.h>
}
#include <irrlicht.h>

#include <btBulletDynamicsCommon.h>
#include <cstdlib>

#include "initdevice.hpp"
#include "menuhandeler.hpp"
#include "lua_api/load_gui.hpp"
#include "lua_api/load_game.hpp"
#include "lua_api/load_core.hpp"
#include "lua_api/load_phys.hpp"
#include "callbackhandeler.hpp"

using namespace irr;
using namespace core;
using namespace scene;
using namespace video;
using namespace io;
using namespace gui;

btDiscreteDynamicsWorld* World;
core::list<btRigidBody*> Objects;

void loadLLibs(lua_State* L){
  luaopen_base(L);
  luaopen_table(L);
  luaopen_io(L);
  luaopen_string(L);
  luaopen_math(L);
}

lua_State* L;
IrrlichtDevice* device;

void loadIrrLibs(lua_State* L, IrrlichtDevice* device){
  printf("Loading guifuncs...\n");
  load_guifuncs(L);
  load_gamefuncs(L);
  load_corefuncs(L);
  load_physfuncs(L);
}

static int GetRandInt(int TMax) { return rand() % TMax; }

// Removes all objects from the world
void ClearObjects() {

	for(list<btRigidBody *>::Iterator Iterator = Objects.begin(); Iterator != Objects.end(); ++Iterator) {
		btRigidBody *Object = *Iterator;

		// Delete irrlicht node
		ISceneNode *Node = static_cast<ISceneNode *>(Object->getUserPointer());
		Node->remove();

		// Remove the object from the world
		World->removeRigidBody(Object);

		delete Object;
	}

	Objects.clear();
}

// Create a box rigid body
void CreateBox(ISceneManager* irrScene, const btVector3 &TPosition, const core::vector3df &TScale, btScalar TMass) {

	// Create an Irrlicht cube
	scene::ISceneNode *Node = irrScene->addCubeSceneNode(1.0f);
	Node->setScale(TScale);
	
    Node->setMaterialFlag(video::EMF_LIGHTING, 1);
	Node->setMaterialFlag(video::EMF_NORMALIZE_NORMALS, true);
	//Node->setMaterialTexture(0, irrDriver->getTexture("rust0.jpg"));

	// Set the initial position of the object
	btTransform Transform;
	Transform.setIdentity();
	Transform.setOrigin(TPosition);

	// Give it a default MotionState
	btDefaultMotionState *MotionState = new btDefaultMotionState(Transform);

	// Create the shape
	btVector3 HalfExtents(TScale.X * 0.5f, TScale.Y * 0.5f, TScale.Z * 0.5f);
	btCollisionShape *Shape = new btBoxShape(HalfExtents);

	// Add mass
	btVector3 LocalInertia;
	Shape->calculateLocalInertia(TMass, LocalInertia);

	// Create the rigid body object
	btRigidBody *RigidBody = new btRigidBody(TMass, MotionState, Shape, LocalInertia);

	// Store a pointer to the irrlicht node so we can update it later
	RigidBody->setUserPointer((void *)(Node));

	// Add it to the world
	World->addRigidBody(RigidBody);
	Objects.push_back(RigidBody);
}

// Create a sphere rigid body
void CreateSphere(ISceneManager* irrScene, const btVector3 &TPosition, btScalar TRadius, btScalar TMass) {

	// Create an Irrlicht sphere
	scene::ISceneNode *Node = irrScene->addSphereSceneNode(TRadius, 32);
	Node->setMaterialFlag(video::EMF_LIGHTING, 1);
	Node->setMaterialFlag(video::EMF_NORMALIZE_NORMALS, true);
	//Node->setMaterialTexture(0, irrDriver->getTexture("ice0.jpg"));

	// Set the initial position of the object
	btTransform Transform;
	Transform.setIdentity();
	Transform.setOrigin(TPosition);

	// Give it a default MotionState
	btDefaultMotionState *MotionState = new btDefaultMotionState(Transform);

	// Create the shape
	btCollisionShape *Shape = new btSphereShape(TRadius);

	// Add mass
	btVector3 LocalInertia;
	Shape->calculateLocalInertia(TMass, LocalInertia);

	// Create the rigid body object
	btRigidBody *RigidBody = new btRigidBody(TMass, MotionState, Shape, LocalInertia);

	// Store a pointer to the irrlicht node so we can update it later
	RigidBody->setUserPointer((void *)(Node));

	// Add it to the world
	World->addRigidBody(RigidBody);
	Objects.push_back(RigidBody);
}

// Converts a quaternion to an euler angle
void QuaternionToEuler(const btQuaternion &TQuat, btVector3 &TEuler) {
	btScalar W = TQuat.getW();
	btScalar X = TQuat.getX();
	btScalar Y = TQuat.getY();
	btScalar Z = TQuat.getZ();
	float WSquared = W * W;
	float XSquared = X * X;
	float YSquared = Y * Y;
	float ZSquared = Z * Z;

	TEuler.setX(atan2f(2.0f * (Y * Z + X * W), -XSquared - YSquared + ZSquared + WSquared));
	TEuler.setY(asinf(-2.0f * (X * Z - Y * W)));
	TEuler.setZ(atan2f(2.0f * (X * Y + Z * W), XSquared - YSquared - ZSquared + WSquared));
	TEuler *= core::RADTODEG;
}

// Runs the physics simulation.
// - TDeltaTime tells the simulation how much time has passed since the last frame so the simulation can run independently of the frame rate.
void UpdatePhysics(u32 TDeltaTime) {

	World->stepSimulation(TDeltaTime * 0.001f, 60);

	btRigidBody *TObject;
	// Relay the object's orientation to irrlicht
	for(core::list<btRigidBody *>::Iterator it = Objects.begin(); it != Objects.end(); ++it) {

		//UpdateRender(*Iterator);
		scene::ISceneNode *Node = static_cast<scene::ISceneNode *>((*it)->getUserPointer());
		TObject = *it;

		// Set position
		btVector3 Point = TObject->getCenterOfMassPosition();
		Node->setPosition(core::vector3df((f32)Point[0], (f32)Point[1], (f32)Point[2]));

		// Set rotation
		btVector3 EulerRotation;
		QuaternionToEuler(TObject->getOrientation(), EulerRotation);
		Node->setRotation(core::vector3df(EulerRotation[0], EulerRotation[1], EulerRotation[2]));

	}
}

// Creates a base box
void CreateStartScene(ISceneManager* smgr) {

	ClearObjects();
	CreateBox(smgr,btVector3(0.0f, 0.0f, 0.0f), core::vector3df(10.0f, 0.5f, 10.0f), 0.0f);
}

int main(int argc, char *argv[]){
    // Initialize bullet
    btBroadphaseInterface *BroadPhase = new btAxisSweep3(btVector3(-1000, -1000, -1000), btVector3(1000, 1000, 1000));
    btDefaultCollisionConfiguration *CollisionConfiguration = new btDefaultCollisionConfiguration();
    btCollisionDispatcher *Dispatcher = new btCollisionDispatcher(CollisionConfiguration);
    btSequentialImpulseConstraintSolver *Solver = new btSequentialImpulseConstraintSolver();
    World = new btDiscreteDynamicsWorld(Dispatcher, BroadPhase, Solver, CollisionConfiguration);
    
  //Create a new lua state, this gets shared everywhere
  lua_State *state = luaL_newstate();
  L = state;
  //Load the lua libraries
  loadLLibs(state);
  //Defined in initdevice.cpp, creates the irrlicht device
  device = spawnIrrDevice(state);
  if (!device)
    return 1;
  //Loads libraries for interfaceing with irrlicht
  loadIrrLibs(state,device);
  printf("Loadded irr libs...\n");
  //Sets the global event handeler
  GlobalEventReceiver ger = GlobalEventReceiver(device);
  device->setEventReceiver(&ger);
  int iErr = luaL_dofile(state,"../data/guitest.lua");
  if(iErr != 0){
    lua_error(state);
    printf("Failed to open lua file:../data/guitest.lua\n");
  }

  //Load some bullet physics stuff

  //Load some menu
  loadMenu("Some menu",device);

  IVideoDriver* driver = device->getVideoDriver();
  ISceneManager* smgr = device->getSceneManager();
  IGUIEnvironment* guienv = device->getGUIEnvironment();
  ITimer* irrTimer = device->getTimer();
  
  device->setWindowCaption(L"Bork[en]gine Demo");
  
  /*
  CreateBox(smgr,
      btVector3(
        GetRandInt(10) - 5.0f, 7.0f,
        GetRandInt(10) - 5.0f),
      core::vector3df(
        GetRandInt(3) + 0.5f,
        GetRandInt(3) + 0.5f,
        GetRandInt(3) + 0.5f),
      1.0f);
  CreateBox(smgr,
      btVector3(0,0,0),
      core::vector3df(10,10,10),
      0.0f);
  CreateSphere(smgr,
      btVector3(
        GetRandInt(10) - 5.0f, 7.0f,
        GetRandInt(10) - 5.0f),
      GetRandInt(5) / 5.0f + 0.2f, 1.0f);
    */

  guienv->addStaticText(L"Hello World! This is the Irrlicht Software renderer!",
		rect<s32>(10,10,260,22), true);

	smgr->addCameraSceneNode(0, vector3df(0,30,-40), vector3df(0,5,0));

  printf("Everything registered, about to start running device!\n");

  u32 TimeStamp = irrTimer->getTime(), DeltaTime = 0;
  while(device->run()){
    if(device->isWindowActive()){
        DeltaTime = irrTimer->getTime() - TimeStamp;
        TimeStamp = irrTimer->getTime();

        UpdatePhysics(DeltaTime);
        
        driver->beginScene(true, true, SColor(255,100,101,140));
    
        smgr->drawAll();
        guienv->drawAll();
    
        driver->endScene();
    }else{
        device->yield();
    }
    lua_getglobal(state,"GAME");
    lua_getfield(state,-1,"tick");
    if(!lua_isnil(state,-1))
      lua_call(state,0,0);
  }
  printf("Claoseing lua state...\n");
  //lua_close(state);
  printf("clearing objects...\n");
  ClearObjects();
  printf("cleared objects\n");
  delete BroadPhase;
  printf("deleted broadphase\n");
  delete CollisionConfiguration;
  printf("deleted collision config\n");
  delete Dispatcher;
  printf("Deleted dispatcher\n");
  delete Solver;
  printf("deleted solver\n");
  
  delete World; //Muah ha ha
  printf("deleted world\n");
  
  device->drop();
  printf("droped device\n");
  
  return 0;
}