namespace Luax
{

	///
	/// 注册工厂，注册class table，以type name为键设置在名称空间上。在注册阶段不会设置元表，等到New方法调用的时候才会。
	/// 
	template<class TYPE>
	void LuaxState::RegisterFactory()
	{
		cc8* type = TYPE::GetLuaxFactoryName();

		lua_State* L = mState;
		LuaxState& state = *this;

		int top = lua_gettop(L); // namespace table
		assert(lua_istable(L, top));

		// class table
		lua_newtable(L);
		TYPE::RegisterLuaxClassShared(state);
		TYPE::RegisterLuaxFactoryClass(state);
		TYPE::RegisterLuaxClass(state);

		// 检测TYPE里面是否没有注册必须的方法
#define _assertmethod(I, NAME) \
		GetField(I, NAME); \
		assert(IsType(-1, LUA_TFUNCTION)); \
		Pop();

		//_assertmethod(-1, "New");

#undef _assertmethod

#if LUAX_ENABLE_NATIVE_EXTEND
		// .Extend()
		lua_pushvalue(state, -1); // class table
		lua_pushcclosure(state, TYPE::_ExtendFactory, 1);
		lua_setfield(state, -2, "Extend");
#endif

		// class["__index"] = class
		lua_pushvalue(state, -1); // class table
		lua_setfield(state, -2, "__index");

		TYPE::SetLuaxClassTableRef(state, -1);

		SetField(top, type);

		// reset top
		lua_settop(L, top);

		// 后处理
		TYPE::RegisterLuaxPostprocess(state);
	}

	///
	/// Singleton
	///
	template<typename TYPE>
	void LuaxState::RegisterSingleton()
	{
		lua_State* L = mState;
		LuaxState& state = *this;

		int top = lua_gettop(L); // namespace table
		assert(lua_istable(L, top));

		// class table.
		lua_newtable(L);
		TYPE::RegisterLuaxClassShared(state);
		TYPE::RegisterLuaxSingletonClass(state);
		TYPE::RegisterLuaxClass(state);

		TYPE::SetLuaxClassTableRef(state, -1);

		lua_pushvalue(state, -1);
		lua_setfield(state, -2, "__index");

#if LUAX_ENABLE_NATIVE_EXTEND
		// .Extend()
		lua_pushvalue(state, -1); // class table
		lua_pushcclosure(state, TYPE::_ExtendSingleton, 1);
		lua_setfield(state, -2, "Extend");
#endif

		cc8* type = TYPE::GetLuaxSingletonName();
		SetField(top, type);

		// reset top
		lua_settop(L, top);

		// 后处理
		TYPE::RegisterLuaxPostprocess(state);
	}

	template<typename TYPE>
	void LuaxState::SetField(int idx, cc8* key, TYPE value)
	{
		if (IsTableOrUserdata(idx))
		{
			idx = AbsIndex(idx);
			this->Push(value);
			lua_setfield(mState, idx, key);
		}
	}

	template<typename TYPE> 
	void LuaxState::SetFieldByIndex(int idx, int key, TYPE value)
	{
		if (IsTableOrUserdata(idx))
		{
			idx = AbsIndex(idx);
			this->Push(value);
			lua_rawseti(mState, idx, key);
		}
	}

	template<typename TYPE>
	TYPE LuaxState::GetField(int idx, cc8* key, TYPE value)
	{
		GetField(idx, key);
		TYPE result = GetValue < TYPE >(-1, value);
		this->Pop();

		return result;
	}

	template<typename TYPE>
	TYPE LuaxState::GetField(int idx, int key, TYPE value)
	{
		GetField(idx, key);
		TYPE result = GetValue < TYPE >(-1, value);
		Pop();

		return result;
	}

	template<typename TYPE>
	TYPE* LuaxState::GetUserdata(int idx)
	{
		void* p = nullptr;

		if (IsType(idx, LUA_TUSERDATA))
		{
			p = *(void**)lua_touserdata(mState, idx);
		}

		return static_cast<TYPE*>(p);
	}

	template<typename TYPE> 
	TYPE* LuaxState::CheckUserdata(int idx)
	{
		if (IsType(idx, LUA_TUSERDATA))
		{
			if (lua_getmetatable(mState, idx)) // ref table 
			{
				if (lua_getmetatable(mState, -1)) // member table 
				{
					if (lua_getmetatable(mState, -1)) // class table 
					{
						TYPE::PushLuaxClassTable(*this); // target class table
						if (lua_rawequal(mState, -1, -2))
						{
							Pop(4); // ref\member\class\target class
							TYPE* udata = GetUserdata<TYPE>(idx);
							return udata; // userdata
						}
						Pop(2); // target class table\class table
					}
					Pop(1); // member table 
				}
				Pop(1); // ref table
			}
		}
		luaL_typerror(mState, idx, TYPE::GetLuaxClassName());
		return nullptr;
	}

}