#include <stdio.h>
#include <stdlib.h>
#include "linkedlist.h"

int initLL (linkedlist *list) {

  if (!list) return NULL_LIST_LL;

  list->head = list->tail = NULL;
  list->count = 0;
  
  return SUCCESS_LL;
}


int addHeadLL (linkedlist *list, void *data) {

  node *newnode;

  if (!list) return NULL_LIST_LL;
  if (!data) return NULL_DATA_LL;

  newnode = malloc (sizeof(node));
  
  newnode->next = list->head;
  newnode->data = data;
  list->head = newnode;
  (list->count)++;

  /* If list was previosuly empty, set tail to only node, newly added */
  list->tail = list->head;

  return SUCCESS_LL;
}


int printLL (const linkedlist *const list, int (*printfn)(const void *, FILE *)) {
  node *index;

  for (index=list->head; index; index=index->next) {
    printfn(index->data, stdout);
    printf ("\n");
  }

  return SUCCESS_LL;
}


int removeHeadLL (linkedlist *list, void **data) {

  node *zombie;

  if (!list) return NULL_LIST_LL;
  if (!list->count) return EMPTY_LIST_LL;
  
  zombie = list->head;
  
  list->head = zombie->next;
  (list->count)--;

  *data = zombie->data;

  free (zombie);
  
  if (!list->count) list->tail = NULL;

  return SUCCESS_LL;
}

int destroylist (linkedlist *list) {
  void *notused;

  if (!list) return NULL_LIST_LL;

  while (list->count)
    removeHeadLL(list, &notused);
    
  return SUCCESS_LL;
}