// ============================================================================
//  Copyright (C) 2001-2014 by Jozef Starosczyk
//  ixen@copyhandler.com
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Library General Public License
//  (version 2) as published by the Free Software Foundation;
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU Library General Public
//  License along with this program; if not, write to the
//  Free Software Foundation, Inc.,
//  59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
// ============================================================================
#ifndef __TSHAREDMODIFICATIONTRACKER_H__
#define __TSHAREDMODIFICATIONTRACKER_H__

namespace serializer
{
	template<class T, class Bitset, size_t ChangeBit>
	class TSharedModificationTracker
	{
	public:
		typedef T value_type;

	public:
		explicit TSharedModificationTracker(Bitset& rBitset) :
			m_tValue(),
			m_rBitset(rBitset)
		{
			MarkAsModified();
		}

		TSharedModificationTracker(const TSharedModificationTracker<T, Bitset, ChangeBit>& rSrc) = delete;

		TSharedModificationTracker(const TSharedModificationTracker<T, Bitset, ChangeBit>& rSrc, Bitset& rBitset) :
			m_tValue(rSrc.m_tValue),
			m_rBitset(rBitset)
		{
			m_rBitset[ChangeBit] = rSrc.m_rBitset[ChangeBit];
		}

		template<class... V>
		explicit TSharedModificationTracker(Bitset& rBitset, const V&... rValues) :
			m_tValue(rValues...),
			m_rBitset(rBitset)
		{
			MarkAsModified();
		}

		TSharedModificationTracker& operator=(const TSharedModificationTracker<T, Bitset, ChangeBit>& rValue)
		{
			if (this != &rValue)
			{
				m_tValue = rValue.m_tValue;
				m_rBitset[ChangeBit] = rValue.m_rBitset[ChangeBit];
			}

			return *this;
		}

		template<class V>
		TSharedModificationTracker& operator=(const V& rValue)
		{
			if (m_tValue != rValue)
			{
				m_tValue = rValue;
				MarkAsModified();
			}

			return *this;
		}

		operator const T&() const
		{
			return m_tValue;
		}

		const T& Get() const
		{
			return m_tValue;
		}

		T& Modify()
		{
			MarkAsModified();
			return m_tValue;
		}

		bool IsModified() const
		{
			return m_rBitset[ChangeBit];
		}

		void MarkAsModified()
		{
			m_rBitset[ChangeBit] = true;
		}

		void MarkAsUnmodified()
		{
			m_rBitset[ChangeBit] = false;
		}

	private:
		T m_tValue;
		Bitset& m_rBitset;
	};
}

#endif