/*
 * Copyright (c) 2025 Quinn Stephens and the OSMORA team.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holder nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _LIST_H
#define _LIST_H 1

struct list_entry {
    struct list_entry *prev;
    struct list_entry *next;
};

struct list {
    struct list_entry *tail;
    struct list_entry *head;
};

static inline void
list_remove(struct list_entry *entry)
{
    entry->prev->next = entry->next;
    entry->next->prev = entry->prev;
}

static inline void
list_append(struct list *list, struct list_entry *entry)
{
    entry->prev = list->tail;
    entry->next = (struct list_entry *)list;
    list->tail->next = entry;
    list->tail = entry;
}

static inline void
list_prepend(struct list *list, struct list_entry *entry)
{
    entry->next = list->head;
    entry->prev = (struct list_entry *)list;
    list->head->prev = entry;
    list->head = entry;
}

static inline void
list_init(struct list *list)
{
    list->tail = (struct list_entry *)list;
    list->head = (struct list_entry *)list;
}

#endif /* !_LIST_H */