#include "tundo.h"

#include <deque></deque>

//-----------------------------------------------------------------------------

using std::for_each;

namespace

{

void deleteUndo(const TUndo *undo) { delete undo; }

void callUndo(const TUndo *undo) { undo->undo(); }

void callRedo(const TUndo *undo) { undo->redo(); }

// void callRepeat(const TUndo* undo) {undo->repeat(); }

class TUndoBlock : public TUndo

{

	vector<tundo *=""> m_undos;</tundo>

	typedef std::vector<tundo *="">::const_iterator Iterator;</tundo>

	typedef std::vector<tundo *="">::const_reverse_iterator ReverseIterator;</tundo>

	mutable bool m_deleted, m_undoing;

public:

	TUndoBlock() : m_deleted(false), m_undoing(false) {}

	~TUndoBlock()

	{

		assert(m_undoing == false);

		assert(m_deleted == false);

		m_deleted = true;

		for_each(m_undos.begin(), m_undos.end(), deleteUndo);

		m_undos.clear();

	}

	int getSize() const

	{

		int size = sizeof(*this);

		for (Iterator cit = m_undos.begin(); cit != m_undos.end(); ++cit)

			size += (*cit)->getSize();

		size += (m_undos.capacity() - m_undos.size()) * sizeof(TUndo *);

		return size;

	}

	int getUndoCount() const

	{

		return (int)m_undos.size();

	}

	void setLast()

	{

		for (UINT i = 1; i < m_undos.size(); i++)

			m_undos[i]->m_isLastInBlock = false;

		m_undos[0]->m_isLastInBlock = true;

	}

	void undo() const

	{

		assert(!m_deleted);

		assert(!m_undoing);

		m_undoing = true;

		//VERSIONE CORRETTA

		for_each(m_undos.rbegin(), m_undos.rend(), callUndo);

		//VERSIONE SBAGLIATA

		//for_each(m_undos.begin(), m_undos.end(), callUndo);

		m_undoing = false;

	}

	void redo() const

	{

		assert(!m_deleted);

		//VERSIONE CORRETTA

		for_each(m_undos.begin(), m_undos.end(), callRedo);

		//VERSIONE SBAGLIATA

		//for_each(m_undos.rbegin(), m_undos.rend(), callRedo);

	}

	//void repeat() const {

	//  for_each(m_undos.begin(), m_undos.end(), callRepeat);

	//}

	void onAdd() {}

	void add(TUndo *undo)

	{

		undo->m_isLastInBlock = true;

		m_undos.push_back(undo);

	}

	void popUndo(int n)

	{

		if (n == -1)

			n = m_undos.size();

		if (m_undos.empty() || n <= 0)

			return;

		while (n > 0 && !m_undos.empty()) {

			TUndo *undo = m_undos.back();

			m_undos.pop_back();

			delete undo;

			n--;

		}

	}

	virtual QString getHistoryString()

	{

		if (m_undos.empty())

			return TUndo::getHistoryString();

		else if ((int)m_undos.size() == 1)

			return m_undos.back()->getHistoryString();

		else {

			return QString("%1  etc..").arg(m_undos.back()->getHistoryString());

		}

	}

	virtual int getHistoryType()

	{

		if (m_undos.empty())

			return TUndo::getHistoryType();

		else

			return m_undos.back()->getHistoryType();

	}

};

}

typedef std::deque<tundo *=""> UndoList;</tundo>

typedef UndoList::iterator UndoListIterator;

typedef UndoList::const_iterator UndoListConstIterator;

//-----------------------------------------------------------------------------

struct TUndoManager::TUndoManagerImp {

	UndoList m_undoList;

	UndoListIterator m_current;

	bool m_skipped;

	int m_undoMemorySize; // in bytes

	vector<tundoblock *=""> m_blockStack;</tundoblock>

public:

	TUndoManagerImp() : m_skipped(false), m_undoMemorySize(0) { m_current = m_undoList.end(); }

	~TUndoManagerImp() {}

	void add(TUndo *undo);

public:

	static struct ManagerPtr {

		TUndoManager *m_ptr;

	public:

		ManagerPtr() : m_ptr(0) {}

		~ManagerPtr()

		{

			if (m_ptr)

				delete m_ptr;

			m_ptr = 0;

		}

	} theManager;

private:

	void doAdd(TUndo *undo);

};

//=============================================================================

TUndoManager::TUndoManagerImp::ManagerPtr TUndoManager::TUndoManagerImp::theManager;

//-----------------------------------------------------------------------------

TUndoManager *TUndoManager::manager()

{

	if (!TUndoManagerImp::theManager.m_ptr)

		TUndoManagerImp::theManager.m_ptr = new TUndoManager;

	return TUndoManagerImp::theManager.m_ptr;

}

//=============================================================================

TUndoManager::TUndoManager()

	: m_imp(new TUndoManagerImp)

{

}

//-----------------------------------------------------------------------------

TUndoManager::~TUndoManager()

{

	//cout << "Distrutto undo manager" << endl;

	assert(m_imp->m_blockStack.empty());

	reset();

}

//-----------------------------------------------------------------------------

void TUndoManager::TUndoManagerImp::add(TUndo *undo)

{

	assert(undo);

	if (!m_blockStack.empty()) {

		assert(m_current == m_undoList.end());

		m_blockStack.back()->add(undo);

	} else

		doAdd(undo);

}

//-----------------------------------------------------------------------------

void TUndoManager::TUndoManagerImp::doAdd(TUndo *undo)

{

	if (m_current != m_undoList.end()) {

		for_each(m_current, m_undoList.end(), deleteUndo);

		m_undoList.erase(m_current, m_undoList.end());

	}

	int i, memorySize = 0, count = m_undoList.size();

	for (i = 0; i < count; i++)

		memorySize += m_undoList[i]->getSize();

	while (count > 100 || (count != 0 && memorySize + undo->getSize() > m_undoMemorySize)) //20MB

	{

		--count;

		TUndo *undo = m_undoList.front();

		m_undoList.pop_front();

		memorySize -= undo->getSize();

		delete undo;

	}

	undo->m_isLastInBlock = true;

	m_undoList.push_back(undo);

	m_current = m_undoList.end();

}

//-----------------------------------------------------------------------------

void TUndoManager::beginBlock()

{

	if (m_imp->m_current != m_imp->m_undoList.end()) {

		for_each(m_imp->m_current, m_imp->m_undoList.end(), deleteUndo);

		m_imp->m_undoList.erase(m_imp->m_current, m_imp->m_undoList.end());

	}

	TUndoBlock *undoBlock = new TUndoBlock;

	m_imp->m_blockStack.push_back(undoBlock);

	m_imp->m_current = m_imp->m_undoList.end();

}

//-----------------------------------------------------------------------------

void TUndoManager::endBlock()

{

	//vogliamo fare anche resize del vector ???

	assert(m_imp->m_blockStack.empty() == false);

	TUndoBlock *undoBlock = m_imp->m_blockStack.back();

	m_imp->m_blockStack.pop_back();

	if (undoBlock->getUndoCount() > 0) {

		undoBlock->setLast();

		m_imp->add(undoBlock);

		emit historyChanged();

	} else {

		delete undoBlock;

		m_imp->m_current = m_imp->m_undoList.end();

	}

}

//-----------------------------------------------------------------------------

bool TUndoManager::undo()

{

	assert(m_imp->m_blockStack.empty());

	UndoListIterator &it = m_imp->m_current;

	if (it != m_imp->m_undoList.begin()) {

		m_imp->m_skipped = false;

		--it;

		(*it)->undo();

		emit historyChanged();

		if (m_imp->m_skipped) {

			m_imp->m_skipped = false;

			return undo();

		}

		return true;

	} else

		return false;

}

//-----------------------------------------------------------------------------

bool TUndoManager::redo()

{

	assert(m_imp->m_blockStack.empty());

	UndoListIterator &it = m_imp->m_current;

	if (it != m_imp->m_undoList.end()) {

		m_imp->m_skipped = false;

		(*it)->redo();

		++it;

		emit historyChanged();

		if (m_imp->m_skipped) {

			m_imp->m_skipped = false;

			return redo();

		}

		return true;

	} else

		return false;

}

//-----------------------------------------------------------------------------

//repeat e' come redo ma non sposta il puntatore al corrente

/*

void TUndoManager::repeat()

{

  assert(m_imp->m_blockStack.empty());

  UndoListIterator &it = m_imp->m_current;

  if (it != m_imp->m_undoList.end())

  {

    (*it)->repeat();

  }

}

*/

//-----------------------------------------------------------------------------

void TUndoManager::skip()

{

	m_imp->m_skipped = true;

}

//-----------------------------------------------------------------------------

void TUndoManager::setUndoMemorySize(int memorySyze)

{

	m_imp->m_undoMemorySize = 1048576 * memorySyze;

}

//-----------------------------------------------------------------------------

void TUndoManager::add(TUndo *undo)

{

	assert(undo);

	if (!undo)

		return;

	m_imp->add(undo);

	Q_EMIT historyChanged();

	undo->onAdd();

	Q_EMIT somethingChanged();

}

//-----------------------------------------------------------------------------

void TUndoManager::reset()

{

	assert(m_imp->m_blockStack.empty());

	m_imp->m_blockStack.clear();

	UndoList &lst = m_imp->m_undoList;

	for_each(lst.begin(), lst.end(), deleteUndo);

	lst.clear();

	m_imp->m_current = m_imp->m_undoList.end();

	Q_EMIT historyChanged();

}

//-----------------------------------------------------------------------------

void TUndoManager::popUndo(int n, bool forward)

{

	if (!forward) {

		if (m_imp->m_blockStack.empty()) {

			if (n == -1) {

				UndoListIterator start = m_imp->m_undoList.begin();

				n = 0;

				while (start != m_imp->m_current)

					++n;

			}

			if (m_imp->m_undoList.empty() || n <= 0)

				return;

			if (m_imp->m_current == m_imp->m_undoList.end()) {

				int i;

				for (i = 0; i < n && m_imp->m_current != m_imp->m_undoList.begin(); i++) {

					m_imp->m_current--;

					delete (*m_imp->m_current);

					m_imp->m_undoList.erase(m_imp->m_current);

					m_imp->m_current = m_imp->m_undoList.end();

				}

			} else {

				TUndo *undo = *m_imp->m_current;

				UndoListIterator start, end = m_imp->m_current;

				if (end == m_imp->m_undoList.begin())

					return;

				int i;

				for (i = 0; i < n && m_imp->m_current != m_imp->m_undoList.begin(); i++)

					m_imp->m_current--;

				start = m_imp->m_current;

				UndoListIterator _end = end;

				while (_end != start) {

					_end--;

					delete (*_end);

				}

				m_imp->m_undoList.erase(start, end);

				m_imp->m_current = m_imp->m_undoList.begin();

				while (*m_imp->m_current != undo)

					m_imp->m_current++;

			}

		} else

			m_imp->m_blockStack.back()->popUndo(n);

		return;

	}

	if (m_imp->m_current == m_imp->m_undoList.end())

		return;

	if (m_imp->m_blockStack.empty()) {

		UndoListIterator end, start = m_imp->m_current++;

		if (n == -1)

			end = m_imp->m_undoList.end();

		else {

			UndoListIterator it = start;

			end = it;

			int i = 0;

			while (i != n && end != m_imp->m_undoList.end()) {

				++end;

				i++;

			}

		}

		for_each(start, end, deleteUndo);

		m_imp->m_undoList.erase(start, end);

		m_imp->m_current = m_imp->m_undoList.end();

	} else

		m_imp->m_blockStack.back()->popUndo(n);

}

//-----------------------------------------------------------------------------

int TUndoManager::getHistoryCount()

{

	return (int)m_imp->m_undoList.size();

}

//-----------------------------------------------------------------------------

int TUndoManager::getCurrentHistoryIndex()

{

	int index = 0;

	UndoListIterator it = m_imp->m_undoList.begin();

	while (1) {

		if (it == m_imp->m_current)

			return index;

		if (it == m_imp->m_undoList.end())

			break;

		index++;

		it++;

	}

	return 0;

}

//-----------------------------------------------------------------------------

TUndo *TUndoManager::getUndoItem(int index)

{

	if (index > (int)m_imp->m_undoList.size() || index <= 0)

		return 0;

	return m_imp->m_undoList.at(index - 1);

}