#pragma once
#include "SHStack.h"
#include "DualPtrList.h"

template<class T> class DListStack : public SHStack< T >
{
public:
    DListStack(long depth = -1);

	virtual ~DListStack();

	virtual bool Pop(T&t);
	virtual bool Push(T const&t);
	virtual void Clear();

	virtual bool GetTopData(T&t);
	virtual long GetDepth();
	virtual T& operator[](long i);

	virtual void GoBack();
	virtual void GoAhead();

protected:
	DualPtrList<T> list;
};


template<class T>
DListStack<T>::DListStack(long depth) : SHStack<T>(depth)
{
}

template<class T>
DListStack<T>::~DListStack()
{
}

template<class T>
bool DListStack<T>::Push(T const&t)
{
	if(this->IsDepthLimited() && GetDepth() >= this->maxDepth)
	{
		return false;
	}
	
	list[list.GetCur()+1] = t;
	this->oldDepth = GetDepth();
	return true;
}

template<class T>
bool DListStack<T>::Pop(T&t)
{
	if(this->IsEmpty())
	{
		return false;
	}
	
	t = list.GetCurData();
	list.DelCur();
	this->oldDepth = GetDepth();
	return true;
}

template<class T>
bool DListStack<T>::GetTopData(T&t)
{
	if(this->IsEmpty())
	{
		return false;
	}
	t = list.GetCurData();
	return true;
}

template<class T>
void DListStack<T>::Clear()
{
	list.Clear();
	this->oldDepth = 0;
}

template<class T>
long DListStack<T>::GetDepth()
{
	return list.GetCur() + 1;
}

template<class T>
void DListStack<T>::GoBack()
{
	if(this->CanGoBack())
	{
		list.MoveToPre();
	}
}

template<class T>
void DListStack<T>::GoAhead()
{
	if(this->CanGoAhead())
	{
		list.MoveToNext();
	}
}

template<class T>
T&  DListStack<T>::operator[](long i)
{
	return list[i];
}