/*=========================================================================

  Program:   ParaView
  Module:    vtkSMStateLocator.h

  Copyright (c) Kitware, Inc.
  All rights reserved.
  See Copyright.txt or http://www.paraview.org/HTML/Copyright.html for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
/**
 * @class   vtkSMStateLocator
 * @brief   Class used to retrieve a given message state based
 * on its GlobalID.
 *
 * vtkSMStateLocator allow a hierarchical way of finding a message state.
*/

#ifndef vtkSMStateLocator_h
#define vtkSMStateLocator_h

#include "vtkPVServerManagerCoreModule.h" //needed for exports
#include "vtkSMMessageMinimal.h"          // needed for vtkSMMessage.
#include "vtkSMObject.h"
#include "vtkWeakPointer.h" // need for observer

class vtkSMProxy;
class vtkSMSession;
class vtkUndoStack;

class VTKPVSERVERMANAGERCORE_EXPORT vtkSMStateLocator : public vtkSMObject
{
public:
  static vtkSMStateLocator* New();
  vtkTypeMacro(vtkSMStateLocator, vtkSMObject);
  void PrintSelf(ostream& os, vtkIndent indent) override;

  //@{
  /**
   * Set/Get a parent locator to search which is used as a backup location
   * to search from if a given state was not found locally.
   */
  vtkSetObjectMacro(ParentLocator, vtkSMStateLocator);
  vtkGetObjectMacro(ParentLocator, vtkSMStateLocator);
  //@}

  /**
   * By initializing the garabage collector the stored state get removed once
   * their is no more chance for them to be reused inside the session.
   */
  void InitGarbageCollector(vtkSMSession*, vtkUndoStack*);

  /**
   * Fill the provided State message with the state found inside the current
   * locator or one of its parent. The method return true if the state was
   * successfully filled.
   * The "useParent" flag allow to disable parent lookup but by default it
   * is set to true.
   */
  virtual bool FindState(vtkTypeUInt32 globalID, vtkSMMessage* stateToFill, bool useParent = true);

  /**
   * Register the given state in the current locator. If a previous state was
   * available, the new one will replace it.
   */
  virtual void RegisterState(const vtkSMMessage* state);

  /**
   * Remove a state for a given proxy inside the local locator.
   * if force is true, it will also remove it from its hierarchical parents.
   */
  virtual void UnRegisterState(vtkTypeUInt32 globalID, bool force);

  /**
   * Remove all the registered states
   * if force is true, it will also remove it from its hierarchical parents.
   */
  virtual void UnRegisterAllStates(bool force);

  /**
   * Return true if the given state can be found locally whitout the help of
   * on the hierarchical parent
   */
  virtual bool IsStateLocal(vtkTypeUInt32 globalID);

  /**
   * Return true if the given state do exist in the locator hierarchy
   */
  virtual bool IsStateAvailable(vtkTypeUInt32 globalID);

  /**
   * Register the given proxy state as well as all its sub-proxy state so if
   * that proxy need to be renew all its sub-proxy will be renew in the exact
   * same state.
   */
  virtual void RegisterFullState(vtkSMProxy* proxy);

protected:
  vtkSMStateLocator();
  ~vtkSMStateLocator() override;

  vtkSMStateLocator* ParentLocator;
  vtkWeakPointer<vtkSMSession> Session;
  vtkWeakPointer<vtkUndoStack> UndoStack;

private:
  vtkSMStateLocator(const vtkSMStateLocator&) = delete;
  void operator=(const vtkSMStateLocator&) = delete;

  class vtkInternal;
  vtkInternal* Internals;
};

#endif
