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

#include "list.h"

void list_init(List *list, void (*destroy)(void *data)) {

list->size = 0;
list->destroy = destroy;
list->head = NULL;
list->tail = NULL;

return;

}

void list_destroy(List *list) {

void               *data;

while (list_size(list) > 0) {

   if (list_rem_next(list, NULL, (void **)&data) == 0 && list->destroy !=
      NULL) {

      list->destroy(data);

   }

}

memset(list, 0, sizeof(List));

return;

}

int list_ins_next(List *list, ListElmt *element, const void *data) {

ListElmt           *new_element;

if ((new_element = (ListElmt *)malloc(sizeof(ListElmt))) == NULL)
   return -1;

new_element->data = (void *)data;

if (element == NULL) {

   if (list_size(list) == 0)
      list->tail = new_element;

   new_element->next = list->head;
   list->head = new_element;

   }

else {

   if (element->next == NULL)
      list->tail = new_element;

   new_element->next = element->next;
   element->next = new_element;

}

list->size++;

return 0;

}

int list_rem_next(List *list, ListElmt *element, void **data) {

ListElmt           *old_element;

if (list_size(list) == 0)
   return -1;

if (element == NULL) {

   *data = list->head->data;
   old_element = list->head;
   list->head = list->head->next;

   if (list_size(list) == 1)
      list->tail = NULL;

   }

else {

   if (element->next == NULL)
      return -1;

   *data = element->next->data;
   old_element = element->next;
   element->next = element->next->next;

   if (element->next == NULL)
      list->tail = element;

}

free(old_element);

list->size--;

return 0;

}