/* list.c - grub list function */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2009  Free Software Foundation, Inc.
 *
 *  GRUB 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.
 *
 *  GRUB 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 GRUB.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <grub/list.h>
#include <grub/misc.h>
#include <grub/mm.h>

GRUB_EXPORT(grub_list_push);
GRUB_EXPORT(grub_list_pop);
GRUB_EXPORT(grub_list_remove);
GRUB_EXPORT(grub_list_iterate);
GRUB_EXPORT(grub_list_insert);
GRUB_EXPORT(grub_prio_list_insert);
GRUB_EXPORT(grub_named_list_find);

void grub_list_push(grub_list_t *head, grub_list_t item) {
	item->next = *head;
	*head = item;
}

void *
grub_list_pop(grub_list_t *head) {
	grub_list_t item;

	item = *head;
	if (item) {
		*head = item->next;
	}

	return item;
}

void grub_list_remove(grub_list_t *head, grub_list_t item) {
	grub_list_t *p, q;

	for (p = head, q = *p; q; p = &(q->next), q = q->next) {
		if (q == item) {
			*p = q->next;
			break;
		}
	}
}

int grub_list_iterate(grub_list_t head, grub_list_hook_t hook, void *closure) {
	grub_list_t p;

	for (p = head; p; p = p->next) {
		if (hook (p, closure)) {
			return 1;
		}
	}

	return 0;
}

void grub_list_insert(grub_list_t *head, grub_list_t item, grub_list_test_t test, void *closure) {
	grub_list_t *p, q;

	for (p = head, q = *p; q; p = &(q->next), q = q->next) {
		if (test (item, q, closure)) {
			break;
		}
	}

	*p = item;
	item->next = q;
}

void *
grub_named_list_find(grub_named_list_t head, const char *name) {
	while (head) {
		if (!strcmp (head->name, name)) {
			return head;
		}

		head = head->next;
	}

	return 0;
}

struct grub_prio_list_insert_closure {
	int inactive;
};

static int
grub_prio_list_insert_test(grub_prio_list_t new_item, grub_prio_list_t item, void *closure) {
	struct grub_prio_list_insert_closure *c = closure;
	int r;

	r = strcmp (new_item->name, item->name);
	if (r) {
		return (r < 0);
	}

	if (new_item->prio >= (item->prio & GRUB_PRIO_LIST_PRIO_MASK)) {
		item->prio &= ~GRUB_PRIO_LIST_FLAG_ACTIVE;
		return 1;
	}

	c->inactive = 1;
	return 0;
}

void grub_prio_list_insert(grub_prio_list_t *head, grub_prio_list_t nitem) {
	struct grub_prio_list_insert_closure c;

	c.inactive = 0;
	grub_list_insert (GRUB_AS_LIST_P (head), GRUB_AS_LIST (nitem), (grub_list_test_t)grub_prio_list_insert_test, &c);
	if (!c.inactive) {
		nitem->prio |= GRUB_PRIO_LIST_FLAG_ACTIVE;
	}
}