#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <memory>
#include <map>
#include <functional>
#include <list>
extern "C" {
	#include <lua.h>
	#include <lauxlib.h>
	#include <lualib.h>
}
#include <btBulletDynamicsCommon.h>
#include "bphysmodel.hpp"
#include <shared/lua_api/common.hpp>
#include <shared/util/tinyobj.hpp>

extern btDiscreteDynamicsWorld* World;
extern std::list<btRigidBody*> Objects;

//newbphysmodel("graphicfile","physicfile",mass,[,{position}][,{lookat}])
static int newbphysmodel(lua_State* L){
	printf("Creating bphysmodel\n");
	int nargs = lua_gettop(L);
	double lx,ly,lz;
	double x,y,z;
	if(nargs > 4){
		//"graphicsfile","physicsfile",{position},{lookat}
		popvector3d(L,&lx,&ly,&lz);
	}
	if(nargs > 3){
		//"graphicsfile","physicsfile",{position}
		popvector3d(L,&x,&y,&z);
	}
	//"graphicsfile","physicsfile"

	double mass = lua_tonumber(L,-1);
	const char *ppath = lua_tostring(L,-2);
	//const char *gpath = lua_tostring(L,-3);
	lua_pop(L,3);

	//ISceneManager *smgr = device->getSceneManager();
	
	//printf("bphysnode, creating the scene node\n");

	////Create the scene node
	//IMesh *gmesh = smgr->getMesh(gpath);
	//ISceneNode *node = smgr->addMeshSceneNode(gmesh,0,-1,vector3df(x,y,z));

	printf("bphysnode, createing the physics body\n");
	//Create the physics body
	//IMesh *pmesh = smgr->getMesh(ppath);
	//printf("We have %d mesh buffers\n",pmesh->getMeshBufferCount());
	tinyobj_attrib_t attrib;
	tinyobj_shape_t *shapes = NULL;
	size_t meshcount;
	tinyobj_material_t *materials = NULL;
	size_t num_materials;

	size_t data_len = 0;
	FILE *objfile = fopen(ppath,"rb");
	fseek(objfile,0,SEEK_END);
	data_len = ftell(objfile);
	fseek(objfile,0,SEEK_SET);
	char *objdata = (char*)malloc(sizeof(char)*data_len);
	fread(objdata, sizeof(char), data_len, objfile);
	fclose(objfile);
	int err = tinyobj_parse_obj(&attrib, &shapes, &meshcount, &materials, &num_materials, objdata, data_len, 0);
	if(err != TINYOBJ_SUCCESS){
		printf("Tinyobj failed to load model:%s\n",ppath);
	}
	//u32 meshcount = pmesh->getMeshBufferCount();
	btTriangleMesh* trimesh = new btTriangleMesh();
	size_t numverts = attrib.num_face_num_verts;
	//size_t stride = 9; //9 = 3 position floats + 3 normal floats + 3 color floats
	size_t face_offset = 0;
	for(size_t i = 0; i < numverts; i++){
		for(size_t j = 0; j < (size_t)attrib.face_num_verts[i] / 3; j++){
			float v[3][3]; //this tri
			tinyobj_vertex_index_t idx0, idx1, idx2;
			idx0 = attrib.faces[face_offset + 3 * j + 0];
			idx1 = attrib.faces[face_offset + 3 * j + 1];
			idx2 = attrib.faces[face_offset + 3 * j + 2];
			for(short k = 0; k < 3; k++){
				int f0, f1, f2;
				f0 = idx0.v_idx;
				f1 = idx1.v_idx;
				f2 = idx2.v_idx;
				v[0][k] = attrib.vertices[3 * (size_t)f0 + k];
				v[1][k] = attrib.vertices[3 * (size_t)f1 + k];
				v[2][k] = attrib.vertices[3 * (size_t)f2 + k];
			}
			btVector3 b1,b2,b3;
			b1 = btVector3(v[0][0],v[0][1],v[0][2]);
			b2 = btVector3(v[1][0],v[1][1],v[1][2]);
			b3 = btVector3(v[2][0],v[2][1],v[2][2]);
			trimesh->addTriangle(b1,b2,b3);
		}
		face_offset += (size_t)attrib.face_num_verts[i];
	}
	printf("Done building trimesh\n");
	btCollisionShape *shape = new btBvhTriangleMeshShape(trimesh,true);
	btTransform tr;
	tr.setIdentity();
	tr.setOrigin(btVector3(x,y,z));
	printf("Created default motion shape\n");
	btDefaultMotionState *ms = new btDefaultMotionState(btTransform(tr));
	btVector3 li;
	shape->calculateLocalInertia(mass, li);
	btRigidBody *rb = new btRigidBody(mass,ms,shape,li);
	//rb->setUserPointer((void*) node);
	World->addRigidBody(rb);
	Objects.push_back(rb);
	printf("Rigid body finished\n");

	//Create the lua representation
	lua_newtable(L);
	lua_pushlightuserdata(L,rb);
	lua_setfield(L,-2,"rigidbody");
	//lua_pushlightuserdata(L,node);
	//lua_setfield(L,-2,"node");
	luaL_getmetatable(L,"phys.physmodel");
	lua_setmetatable(L,-2);
	printf("finished creating the lua representation\n");

	return 1;
}

static const luaL_reg bphysmodel_f[] = {
	{"newphysmodel",           newbphysmodel},
	{0,0},
};

static const luaL_reg bphysmodel_m[] = {
	{0, 0},
};

int bphysmodel_register(lua_State* L){

	//device = d;

	//printf("bphysmodel registered\n");

	luaL_newmetatable(L, "phys.physmodel");//{}
	luaL_register(L,NULL,bphysmodel_m);
	//luaL_register(L,NULL,igeneric_m); //Inherit all the things to do with scene nodes
	
	lua_getglobal(L,"phys");
	luaL_register(L,NULL,bphysmodel_f);

	return 1;
}