#include <stdlib.h>
#include <string.h>
#include "stack.h"

stack_t* Stack_free_top(stack_t *pObj)
{
	stack_t *pCurr, *pNext;

	if (pObj == NULL)
		return pObj;

	pCurr = pObj->pNext;
	while(pCurr)
	{
		if (pCurr->pData)
			jfree(pCurr->pData);
		pNext = pCurr->pNext;
		jfree(pCurr);
		pCurr = pNext;
	}
	return pObj;
}

stack_t* Stack_free(stack_t *pObj)
{
	stack_t *pCurr;

	if (pObj == NULL)
		return pObj;

	while(pObj->pNext)
		pObj = pObj->pNext;

	while(pObj)
	{
		pCurr = pObj->pPrev;
		if (pObj->pData)
			jfree(pObj->pData);
		jfree(pObj);
		pObj = pCurr;
	}
	return pObj;
}

stack_t* Stack_push(stack_t *pObj, void **ppData, uint32_t size)
{
	stack_t *pCurr;

	if (!pObj)
	{
		pCurr = (stack_t*)jmalloc(sizeof(stack_t));
		memset(pCurr, 0, sizeof(stack_t));
	}
	else
	{
		pCurr = pObj->pNext;
		if (!pCurr)
		{
			pCurr = (stack_t*)jmalloc(sizeof(stack_t));
			memset(pCurr, 0, sizeof(stack_t));
		}
	}
	pCurr->pPrev = pObj;

	if (size)
	{
		if (!pCurr->pData)
			pCurr->pData = (void*)jmalloc(size);
		if (pCurr->pPrev)
		{
			if (pCurr->pPrev->size == size)
				memcpy(pCurr->pData, pCurr->pPrev->pData, size);
		}
		else
			memset(pCurr->pData, 0, size);
	}
	pCurr->size = size;
	*ppData = pCurr->pData;
	return pCurr;

}

stack_t* Stack_pop(stack_t *pObj, void **ppData)
{
	stack_t *pCurr;

	if (pObj == NULL)
		return pObj;

	if (pObj->pPrev == NULL)
		return pObj->pPrev;

	pCurr = pObj->pPrev;
	*ppData = pCurr->pData;

	return pCurr;
}