/*
 * Copyright (C) 2016+ AzerothCore <www.azerothcore.org>, released under GNU GPL v2 license, you may redistribute it and/or modify it under version 2 of the License, or (at your option), any later version.
 */

#ifndef _PLAYERBOT_LAZYCALCULATEDVALUE_H
#define _PLAYERBOT_LAZYCALCULATEDVALUE_H

template <class TValue, class TOwner>
class LazyCalculatedValue
{
    public:
        typedef TValue (TOwner::*Calculator)();

    public:
        LazyCalculatedValue(TOwner* owner, Calculator calculator) : calculator(calculator), owner(owner)
        {
            Reset();
        }

    public:
        TValue GetValue()
        {
            if (!calculated)
            {
                value = (owner->*calculator)();
                calculated = true;
            }

            return value;
        }

        void Reset()
        {
            calculated = false;
        }

    protected:
        Calculator calculator;
        TOwner* owner;
        bool calculated;
        TValue value;
};

#endif