#pragma once

#ifndef T_UNDO_INCLUDED

#define T_UNDO_INCLUDED

#include <memory></memory>

// TnzCore includes

#include "tsmartpointer.h"

// Qt includes

#include <qobject></qobject>

#include <qstring></qstring>

#undef DVAPI

#undef DVVAR

#ifdef TNZCORE_EXPORTS

#define DVAPI DV_EXPORT_API

#define DVVAR DV_EXPORT_VAR

#else

#define DVAPI DV_IMPORT_API

#define DVVAR DV_IMPORT_VAR

#endif

//************************************************************************

//    TUndo  class

//************************************************************************

class DVAPI TUndo {

public:

  // To be called in the last of the block when undo

  bool m_isLastInBlock = true;

  // To be called in the last of the block when redo

  bool m_isLastInRedoBlock = true;

public:

  TUndo() {}

  virtual ~TUndo() {}

  virtual int getSize() const = 0;

  virtual void undo() const = 0;

  virtual void redo() const = 0;

  virtual void onAdd() {}

  // for history viewer panel

  virtual QString getHistoryString() {

    return QObject::tr("Unidentified Action");

  }

  virtual int getHistoryType() { return 0; }  // HistoryType::Unidentified

private:

  // Noncopyable

  TUndo(const TUndo &undo);

  TUndo &operator=(const TUndo &undo);

};

//************************************************************************

//    TUndoManager  class

//************************************************************************

class DVAPI TUndoManager final : public QObject {

  Q_OBJECT

public:

  TUndoManager();

  ~TUndoManager();

  static TUndoManager *manager();

  void beginBlock();

  void endBlock();

  void add(TUndo *undo);

  bool undo();

  bool redo();

  void reset();

  /*!If forward = false remove n elements in the stack before m_imp->m_current;

else if forward = true remove n elements in the stack after m_imp->m_current.

If n = -1 remove all elements before or after m_imp->m_current.*/

  void popUndo(int n = -1, bool forward = false);

  //! undo() and redo() methods call TUndoManager::manager()->skip() if

  //! they want another undo/redo performed

  void skip();

  //! Set the size of memory used for undo redo.

  //! \b memorySyze is expressed in MB

  void setUndoMemorySize(int memorySyze);

  // for history viewer pane

  int getHistoryCount();

  int getCurrentHistoryIndex();

  TUndo *getUndoItem(int index);

Q_SIGNALS:

  void historyChanged();

  void somethingChanged();

private:

  struct TUndoManagerImp;

  std::unique_ptr<tundomanagerimp> m_imp;</tundomanagerimp>

private:

  // Noncopyable

  TUndoManager(const TUndoManager &);

  TUndoManager &operator=(const TUndoManager &);

};

//************************************************************************

//    TUndoScopedBlock  class

//************************************************************************

struct TUndoScopedBlock {

  TUndoScopedBlock() { TUndoManager::manager()->beginBlock(); }

  ~TUndoScopedBlock() { TUndoManager::manager()->endBlock(); }

private:

  // Noncopyable

  TUndoScopedBlock(const TUndoScopedBlock &);

  TUndoScopedBlock &operator=(const TUndoScopedBlock &);

};

#endif  // T_UNDO_INCLUDED