/* grecs - Gray's Extensible Configuration System
   Copyright (C) 2007-2011 Sergey Poznyakoff

   Grecs is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 3 of the License, or (at your
   option) any later version.

   Grecs is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License along
   with Grecs. If not, see <http://www.gnu.org/licenses/>. */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <grecs.h>
#include <grecs-gram.h>
#include <stdlib.h>
#include <string.h>

struct grecs_list *
grecs_list_create()
{
	struct grecs_list *lp = grecs_malloc(sizeof(*lp));
	memset(lp, 0, sizeof(*lp));
	return lp;
}

size_t
grecs_list_size(struct grecs_list *lp)
{
	return lp ? lp->count : 0;
}

void
grecs_list_append(struct grecs_list *lp, void *val)
{
	struct grecs_list_entry *ep = grecs_malloc(sizeof(*ep));
	ep->data = val;
	ep->next = NULL;
	if (lp->tail)
		lp->tail->next = ep;
	else
		lp->head = ep;
	lp->tail = ep;
	lp->count++;
}

void
grecs_list_push(struct grecs_list *lp, void *val)
{
	struct grecs_list_entry *ep = grecs_malloc(sizeof(*ep));
	ep->data = val;
	ep->next = lp->head;
	lp->head = ep;
	lp->count++;
}

void *
grecs_list_pop(struct grecs_list *lp)
{
	void *data;
	struct grecs_list_entry *ep = lp->head;
	if (ep)	{
		data = ep->data;
		lp->head = ep->next;
		if (!lp->head)
			lp->tail = NULL;
		lp->count--;
		free (ep);
	} else
		data = NULL;
	return data;
}

void
grecs_list_clear(struct grecs_list *lp)
{
	struct grecs_list_entry *ep = lp->head;

	while (ep) {
		struct grecs_list_entry *next = ep->next;
		if (lp->free_entry)
			lp->free_entry(ep->data);
		free(ep);
		ep = next;
	}
	lp->head = lp->tail = NULL;
	lp->count = 0;
}

void
grecs_list_free(struct grecs_list *lp)
{
	grecs_list_clear(lp);
	free(lp);
}

static int
_ptrcmp(const void *a, const void *b)
{
	return a != b;
}

void *
grecs_list_locate(struct grecs_list *lp, void *data)
{
	struct grecs_list_entry *ep;
	int (*cmp)(const void *, const void *) = lp->cmp ? lp->cmp : _ptrcmp;

	for (ep = lp->head; ep; ep = ep->next) {
		if (cmp(ep->data, data) == 0)
			return ep->data;
	}
	return NULL;
}

void *
grecs_list_index(struct grecs_list *lp, size_t idx)
{
	struct grecs_list_entry *ep;
	
	for (ep = lp->head; ep && idx; ep = ep->next, idx--)
		;
	return ep ? ep->data : NULL;
}

void *
grecs_list_remove_tail(struct grecs_list *lp)
{
	void *data;
  
	if (!lp->head)
		return NULL;
	data = lp->tail;
	if (lp->head == lp->tail) {
		free(lp->tail);
		lp->head = lp->tail = NULL;
		lp->count = 0;
	} else {
		struct grecs_list_entry *ep;
      
		for (ep = lp->head; ep->next != lp->tail; ep = ep->next)
			;
		free(lp->tail);
		ep->next = NULL;
		lp->tail = ep;
	}
	return data;
}