/*
 * ValueChangeAction.hpp
 *
 *  Created on: 10 θών. 2020 γ.
 *      Author: LeonidTitov
 */

#ifndef UMLIBRARY_SCHEMATIC_ACTION_VALUECHANGEACTION_HPP_
#define UMLIBRARY_SCHEMATIC_ACTION_VALUECHANGEACTION_HPP_

#include "../../systemic/IFunctor.hh"
#include "../../systemic/IValue.hpp"
#include "../../systemic/IProcess.hh"

namespace schematic { namespace functor {

template<typename ValueType>
struct ValueChangeAction : public systemic::IProcess {

    typedef systemic::IValue<ValueType> Value;
    typedef systemic::IFunctor<void> Action;

    Value & value;
    Action & action;

    const ValueType expected;
    ValueType previous;

    void process();

    ValueChangeAction( Value & value, Action & action, ValueType expected ) : value(value), action(action), expected(expected), previous(expected) {}

};

}
}

template<typename ValueType>
inline void schematic::functor::ValueChangeAction<ValueType>::process() {

    ValueType current = value;

    if( current == expected and previous != expected )
        action();

    previous = current;

}

#endif /* UMLIBRARY_SCHEMATIC_ACTION_VALUECHANGEACTION_HPP_ */