/*
  Copyright (c) 2023 Alex Diener
  
  This software is provided 'as-is', without any express or implied
  warranty. In no event will the authors be held liable for any damages
  arising from the use of this software.
  
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
  
  Alex Diener alex@ludobloom.com
*/

#ifndef __UndoStack_H__
#define __UndoStack_H__

typedef struct UndoStack UndoStack;
#define UndoStack_superclass StemObject

#include "stemobject/StemObject.h"
#include "utilities/UndoStateDelta.h"

typedef struct UndoStack_node {
	unsigned int uniqueID;
	UndoStateDelta * stateDelta;
} UndoStack_node;

#define UndoStack_ivars \
	StemObject_ivars \
	\
	void * target; \
	unsigned int nodeCount; \
	unsigned int nodeAllocatedCount; \
	UndoStack_node * nodes; \
	unsigned int nextNodeID; \
	unsigned int currentDepth;

#define UndoStack_vtable(self_type) \
	StemObject_vtable(self_type)

stemobject_declare(UndoStack)

// target is an arbitrary pointer that will be passed to UndoStateDelta's revert and apply functions
UndoStack * UndoStack_create(void * target);
bool UndoStack_init(UndoStack * self, void * target);
void UndoStack_dispose(UndoStack * self);
UndoStack * UndoStack_copy(UndoStack * self);

void UndoStack_appendNode(UndoStack * self, compat_type(UndoStateDelta *) stateDelta);
bool UndoStack_canUndo(UndoStack * self);
bool UndoStack_canRedo(UndoStack * self);
UndoStateDelta * UndoStack_getStateDeltaForUndo(UndoStack * self);
UndoStateDelta * UndoStack_getStateDeltaForRedo(UndoStack * self);
bool UndoStack_undo(UndoStack * self);
bool UndoStack_redo(UndoStack * self);
unsigned int UndoStack_getCurrentNodeID(UndoStack * self);
void UndoStack_removeAllNodes(UndoStack * self);

#endif