#include "tidentifiable.h"

#include <set></set>

namespace

{

class IdentifierTable

{ // singleton

	unsigned long m_lastId;

	std::map<unsigned *="" long,="" tidentifiable=""> m_table;</unsigned>

	std::set<tidentifiable *=""> m_objects;</tidentifiable>

	IdentifierTable() : m_lastId(0) {}

public:

	static IdentifierTable *instance()

	{

		// NON DEVE MORIRE

		//static IdentifierTable _instance;

		//return &_instance;

		static IdentifierTable *_instance = 0;

		if (!_instance)

			_instance = new IdentifierTable;

		return _instance;

	}

	unsigned long getNextId()

	{

		return ++m_lastId;

	}

	void insert(TIdentifiable *o)

	{

		unsigned long id = o->getIdentifier();

		std::map<unsigned *="" long,="" tidentifiable="">::iterator it = m_table.find(id);</unsigned>

		if (it != m_table.end()) {

			if (it->second == o)

				return;

			m_objects.erase(it->second);

			it->second = o;

		} else {

			m_table[id] = o;

		}

		m_objects.insert(o);

	}

	void erase(TIdentifiable *o)

	{

		unsigned long id = o->getIdentifier();

		m_table.erase(id);

		m_objects.erase(o);

	}

	TIdentifiable *fetch(unsigned long id)

	{

		std::map<unsigned *="" long,="" tidentifiable="">::iterator it = m_table.find(id);</unsigned>

		return it == m_table.end() ? 0 : it->second;

	}

};

} // namespace

TIdentifiable::TIdentifiable()

	: m_id(0)

{

}

TIdentifiable::~TIdentifiable()

{

	if (m_id != 0)

		IdentifierTable::instance()->erase(this);

}

TIdentifiable::TIdentifiable(const TIdentifiable &src)

	: m_id(src.m_id)

{

}

const TIdentifiable &TIdentifiable::operator=(const TIdentifiable &src)

{

	if (src.m_id != m_id && m_id != 0)

		IdentifierTable::instance()->erase(this);

	m_id = src.m_id;

	return *this;

}

void TIdentifiable::setIdentifier(unsigned long id)

{

	bool wasStored = m_id > 0 && IdentifierTable::instance()->fetch(m_id) == this;

	if (m_id != id && m_id != 0)

		IdentifierTable::instance()->erase(this);

	m_id = id;

	if (wasStored)

		IdentifierTable::instance()->insert(this);

}

void TIdentifiable::setNewIdentifier()

{

	setIdentifier(IdentifierTable::instance()->getNextId());

}

void TIdentifiable::storeByIdentifier()

{

	assert(getIdentifier() >= 1);

	IdentifierTable::instance()->insert(this);

}

TIdentifiable *TIdentifiable::fetchByIdentifier(unsigned long id)

{

	return IdentifierTable::instance()->fetch(id);

}