extern "C" {
  #include <lua.h>
  #include <lauxlib.h>
  #include <lualib.h>
}
#include <btBulletDynamicsCommon.h>
#include <shared/lua_api/common.hpp>

/***
@module phys
*/


/*Physics things from lua have the form of:
{
	rigidbody = btRigidBody,
	node = ISceneNode,
}
*/

/***
Sets the direction of gravity on this object.
@function rigidbody:setgravity({x,y,z})
@tparam vector3d direction The direction to make gravity point
*/
//rigidbody:setgravity({x,y,z})
int setgravity(lua_State *L){
	double x,y,z;
	popvector3d(L,&x,&y,&z);

	lua_getfield(L,-1,"rigidbody");
	btRigidBody *r = (btRigidBody*)lua_touserdata(L,-1);
	lua_pop(L,2);

	btVector3 v = btVector3(x,y,z);

	r->setGravity(v);

	return 0;
}

/***
Gets the direction of gravity on this object.
@function rigidbody:getgravity()
@treturn vector3d The direction of gravity on this object.
*/
//rigidbody:getgravity()
int getgravity(lua_State *L){
	lua_getfield(L,-1,"rigidbody");//{rigidbody},ud_rigidbody
	btRigidBody *r = (btRigidBody*)lua_touserdata(L,-1);
	lua_pop(L,2);//

	btVector3 v = r->getGravity();
	pushvector3d(L,v.x(),v.y(),v.z());

	return 0;
}

/***
Apply force at a reletive offset.
@function rigidbody:applyforce(direction, offset = {0,0,0})
@tparam vector3d direction The direction of the force to apply
@tparam vector3d offset The offset from the center of gravity to apply the force
*/
//rigidbody:applyforce({x,y,z}[,{rx,ry,rz}])
int applyforce(lua_State *L){
	double rx,ry,rz;
	rx = 0;
	ry = 0;
	rz = 0;
	if(lua_gettop(L) > 2){
		popvector3d(L,&rx,&ry,&rz);//{phys},{x,y,z}
	}

	double x,y,z;
	popvector3d(L,&x,&y,&z);//{phys}

	lua_getfield(L,-1,"rigidbody");
	btRigidBody *r = (btRigidBody*)lua_touserdata(L,-1);
	lua_pop(L,2);

	btVector3 v = btVector3(x,y,z);
	btVector3 o = btVector3(rx,ry,rz);

	r->applyForce(v,o);
	
	return 0;
}

/***
Gets the damping applied to this rigidbody
@function rigidbody:getldamping()
@treturn number damping The ammount of damping applied to the object's momentum
*/
//rigidbody:getldamping()
int getlineardamping(lua_State *L){
	lua_getfield(L,-1,"rigidbody");
	btRigidBody *r = (btRigidBody*)lua_touserdata(L,-1);
	lua_pop(L,2);

	double damp = r->getLinearDamping();
	lua_pushnumber(L,damp);

	return 1;
}

/***
Sets the angular factor of the rigidbody
TODO:What does this actually do?
@function rigidbody:setangfactor(vec3 dir)
@tparam vector3 dir The direction to set the angular factor
*/
int setangfactor(lua_State *L){
	double x,y,z;
	popvector3d(L,&x,&y,&z);
	lua_getfield(L,-1,"rigidbody");
	btRigidBody *r = (btRigidBody*)lua_touserdata(L,-1);
	lua_pop(L,2);
	r->setAngularFactor(btVector3(x,y,z));
	return 0;
}

/***
Gets the angular damping applied to this rigidbody
@function rigidbody:getadamping()
@treturn number damping The ammount of damping applied to angular momentum
*/
//rigidbody:getadamping()
int getangulardamping(lua_State *L){
	lua_getfield(L,-1,"rigidbody");
	btRigidBody *r = (btRigidBody*)lua_touserdata(L,-1);
	lua_pop(L,2);

	double damp = r->getAngularDamping();
	lua_pushnumber(L,damp);

	return 1;
}

/***
Gets the velocity of this object
@function rigidbody:getvelocity()
@treturn vector3 The velocity in each direction
*/
//rigidbody:getvelocity()
int getvelocity(lua_State *L){
	btVector3 vel;
	lua_getfield(L,-1,"rigidbody");
	btRigidBody *r = (btRigidBody*)lua_touserdata(L,-1);

	vel = r->getLinearVelocity();
	pushvector3d(L,(double)vel.x(),(double)vel.y(),(double)vel.z());

	return 1;
}

/***
Sets the velocity of this object
@function rigidbody:setvelocity()
@tparam vector3d direction The ammount on each axis to set the velocity of this object.
*/
//rigidbody:setvelocity({x,y,z})
int setvelocity(lua_State *L){
	double x,y,z;
	popvector3d(L,&x,&y,&z);
	btVector3 newvel = btVector3(x,y,z);

	lua_getfield(L,-1,"rigidbody");
	btRigidBody *r = (btRigidBody*)lua_touserdata(L,-1);
	lua_pop(L,2);

	r->setLinearVelocity(newvel);

	return 0;
}

/***
Activates this object.
If this object was sleeping, it will move again. If you are using
applyforce or setvelocity, you will need to activate() the rigidbody for it
to move.
@function rigidbody:activate()
*/
//rigidbody:activate()
int activate(lua_State *L){
	lua_getfield(L,-1,"rigidbody");
	btRigidBody *r = (btRigidBody*)lua_touserdata(L,-1);
	lua_pop(L,2);

	r->activate();

	return 0;
}

/***
Sets the damping of this object.
@function rigidbody:setdamping(damping,angular_damping)
@tparam number damping The ammount of damping the object should put on it's movement.
@tparam number angular_damping The ammount of damping the object should put on it's angular momentum
*/
//rigidbody:setdamping(lineardamping, angulardamping)
int setdamping(lua_State *L){
	double adamp,ldamp;
	adamp = lua_tonumber(L,-1);
	ldamp = lua_tonumber(L,-2);
	lua_pop(L,2);

	lua_getfield(L,-1,"rigidbody");
	btRigidBody *r = (btRigidBody*)lua_touserdata(L,-1);
	lua_pop(L,2);

	r->setDamping(adamp,ldamp);

	return 0;
}

extern const luaL_reg brigidbody_m[] = {
	{"setgravity",       setgravity},
	{"applyforce",       applyforce},
	{"getldamping",      getlineardamping},
	{"getadamping",      getangulardamping},
	{"setdamping",       setdamping},
	{"activate",         activate},
	{"getvelocity",      getvelocity},
	{"setvelocity",      setvelocity},
	{"setangfactor",     setangfactor},
	{NULL, NULL}
};