MemberFunction.h

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// File: MemberFunction.h
// Description: A wrapper around a std::function bound to an instance of a class
//              that lets us compare if they are the same and have the same owner (std::function does not natively support this functionality)
//              Basically, a way to store a member function and call it later
// Author(s): Ori Balashov (ori.balashov@digipen.edu)
// 2025 / 10 / 25
// (C) Digipen 2025
//   ____   __                  __  __
// /\__  _\/\ \                /\ \/\ \
// \/_/\ \/\ \ \___      __    \ \ \_\ \    ___   __  __    ____     __
//    \ \ \ \ \  _ `\  /'__`\   \ \  _  \  / __`\/\ \/\ \  /',__\  /'__`\
//     \ \ \ \ \ \ \ \/\  __/    \ \ \ \ \/\ \L\ \ \ \_\ \/\__, `\/\  __/
//      \ \_\ \ \_\ \_\ \____\    \ \_\ \_\ \____/\ \____/\/\____/\ \____\
//       \/_/  \/_/\/_/\/____/     \/_/\/_/\/___/  \/___/  \/___/  \/____/
#pragma once
#include <functional>
#include <string>
 
#include "Framework/GameObject.h"
 
class GameObject;
 
namespace th
{
template <typename returnType, typename... parameters>
class MemberFunction
{
public:
    MemberFunction() = delete;

    MemberFunction(std::function<returnType(parameters...)> function, std::string nameOfFunction, GameObject* funcOwner)
        : actualFunction(std::move(function))
        , functionName(std::move(nameOfFunction))
        , functionOwner(funcOwner)
    {
    }

    auto operator==(const MemberFunction& rhs) const -> bool
    {
        if (hasValidOwner() && rhs.hasValidOwner())
        {
            return functionName == rhs.functionName && functionOwner->getUUID() == rhs.functionOwner->getUUID();
        }
        return false;
    }

    auto operator()(parameters... inputParameter) -> returnType
    {
        return actualFunction(inputParameter...);
    }

    auto hasValidOwner() const -> bool
    {
        if (functionOwner->destroyed())
        {
            return false;
        }
        return true;
    }
 
    [[nodiscard]] auto function_owner() const -> GameObject*
    {
        return functionOwner;
    }
 
    [[nodiscard]] auto function_name() const -> const std::string&
    {
        return functionName;
    }
 
private:
    // The function (should be std::bound_front to the owner before being put into the class)
    std::function<returnType(parameters...)> actualFunction;
    // The name of the function being bound
    std::string functionName;
 
    // The object that is associated with the member function
    GameObject* functionOwner;
};
}