/** lg2d PhysicalWorld class.
 * Represents a "world" in which all physical objects exist. Used internally by
 * the Scene class.
 */
#include <Box2D/Box2D.h>

#ifdef __cplusplus
extern "C" {
#endif

#include <lua5.1/lua.h>
#include <lua5.1/lauxlib.h>
#include <lua5.1/lualib.h>
#include <string.h>

//Prefix of all Lua registry table keys to prevent collision with libraries
#define __s(x) _s(x)
#define _s(x) #x
#define LUA_REGISTRY_PREFIX "LG2D" LUANAME ":"

/* Convenient macros. */
/* see http://tinyurl.com/42mood if you don't understand while(0). */
#define EXPORT_FUNC(f) {#f, Lua_PhysicalWorld_##f}
#define LUA_FUNC_NAME(f) Lua_PhysicalWorld_##f
#define LUA_FUNC(f) static int Lua_PhysicalWorld_##f(lua_State *Lua)
#define GET_SELF() PhysicalWorld *self = \
		(PhysicalWorld*)((PhysicalWorld **)lua_touserdata(Lua, 1))[0]
#define GET_PARENT() lua_pushstring(Lua, "parent");\
	lua_rawget(Lua, 1);\
	PhysicalWorld *parent = (PhysicalWorld*)lua_touserdata(Lua, -1);\
	lua_pop(Lua, 1);

#define LUA_PUSH_TABLE_VALUE(luastate, keytype, key, valtype, val) do {\
	lua_push##keytype((luastate), (key));\
	lua_push##valtype((luastate), (val));\
	lua_settable((luastate), -3);\
} while(0)

#define LUA_PUSH_NAMED_OBJECT_FUNC(luastate, funcname, obj, name) do {\
	lua_pushstring((luastate), (#funcname));\
	lua_pushcfunction((luastate), (Lua_##obj##_##name));\
	lua_settable((luastate), -3);\
} while(0)

#define LUA_RETURN_ERRMSG(luastate, message) do {\
	/* DebugOut(DO_ALL, "%s:%d: LUA_PUSH_ERRMSG: %s\n", __FILE__, __LINE__, (message));\ */\
	lua_pushnil((luastate));\
	lua_pushstring((luastate), (message));\
	return 2;\
} while(0)

#define LUA_RETURN_ERRMSGF(luastate, ...) do {\
	lua_pushnil((luastate));\
	lua_pushfstring((luastate), __VA_ARGS__);\
	return 2;\
} while(0)

#define LUA_RETURN_NIL(luastate) do {\
	lua_pushnil(luastate);\
	return 1;\
} while(0)

/*
#ifdef __cplusplus
}
#endif */

class PhysicalWorld {
	public:
		static void GetRefsTable(lua_State *Lua);

		PhysicalWorld(lua_State *Lua);
		~PhysicalWorld();

		//Lua metamethods
		int __index(lua_State *Lua);

		//variables accessible to Lua. note that each instance also functions
		//like a table; arbitrary values can be stored in it.

	protected:
		lua_State *Lua;
		b2World *World;

	private:

};

/* #ifdef __cplusplus
extern "C" {
#endif */

/** Function prototypes.
 */
LUA_FUNC(Create);
LUA_FUNC(Meta_index);
LUA_FUNC(Meta_newindex);
LUA_FUNC(Meta_gc);

LUALIB_API int LUAOPENFUNC (lua_State *Lua);

#ifdef __cplusplus
}
#endif