#include "fifo2.h"
#include <memory>

Queue* QCreate()
{
  Queue* p = (Queue*)calloc(1,sizeof(Queue));
  if( !p )
  {
    printf("can't alloc memory");
    return NULL;
 }
  QItem* w = (QItem*)calloc(1, sizeof(QItem));
  if(!w)
  {
    printf("can't alloc memory");
    return NULL;
  }
  p->pHead = p->pTail = w;
  return p;
}
int QisEmpty(Queue* q)
{
    return !(q->pHead->pNext);
}
void QEnQueue(Queue* q, int x)
{
  QItem* p = (QItem*)calloc(1, sizeof(QItem));     //warunek czy przydzielono pamiec
  if( !p )
  {
    printf("nie znaleziono wolnej panieci WYNIK ERROR");
    return;
  }
 q->pTail->pNext = p;      //dodaje nowe pudelko
  q->pTail = p;    //ptail wskazuje na ost element
  p->nKey = x;      //daje wartosc ost elem

}
int QDecQueue(Queue* q)
{
  if( !q )
  {
    printf("ERROR:Queue is not even created");
    return 5;
  }
  if( QisEmpty(q) )
  {
    printf("ERROR:Queue is empty");
    return 5;
  }
  QItem* p = q->pHead->pNext;

  int x = p->nKey;
  q->pHead->pNext = p->pNext;
  free(p);
  if( QisEmpty(q) )
    q->pTail = q->pHead;  //!!!               wyzej sprawdzam warunek

  return x;                       //return .. q->pHead->pNext->nKey
}
void QClear(Queue* q)
{
  if( !q )
  {
    printf("ERROR:Queue is not even created");
    return;
  }
  if(QisEmpty(q) )
  {
    printf("can't clear queue -->queue has been already cleared \n");
    return;
  }
  while( !QisEmpty(q) )
    QDecQueue(q);
}
void QDel(Queue** q)                  //!!!!!
{
 if( !*q )
 {
   printf("ERROR:Queue is not even created");
   return;
 }
    QClear(*q);
    free(*q);
  *q = NULL;
}








/*
//////////////////QEnQUEUE!
QItem* p = (QItem*)calloc(1, sizeof(QItem));     //warunek czy przydzielono pamiec
if( !p )
{
  printf("nie znaleziono wolnej panieci WYNIK ERROR");
  return;
}
//if( !q->pHead->pNext )
q->pTail->pNext = p;      //dodaje nowe pudelko
                          //  else
                          //q->pHead->pNext = p;      //make first item

q->pTail = p;    //ptail wskazuje na ost element
p->nKey = x;      //daje wartosc ost elem

*/