/* Simple Plugin API */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */

#ifndef SPA_LIST_H
#define SPA_LIST_H

#ifdef __cplusplus
extern "C" {
#endif

/**
 * \defgroup spa_list List
 * Doubly linked list data structure
 */

/**
 * \addtogroup spa_list List
 * \{
 */

struct spa_list {
	struct spa_list *next;
	struct spa_list *prev;
};

#define SPA_LIST_INIT(list) ((struct spa_list){ (list), (list) })

static inline void spa_list_init(struct spa_list *list)
{
	*list = SPA_LIST_INIT(list);
}

static inline int spa_list_is_initialized(struct spa_list *list)
{
	return !!list->prev;
}

#define spa_list_is_empty(l)  ((l)->next == (l))

static inline void spa_list_insert(struct spa_list *list, struct spa_list *elem)
{
	elem->prev = list;
	elem->next = list->next;
	list->next = elem;
	elem->next->prev = elem;
}

static inline void spa_list_insert_list(struct spa_list *list, struct spa_list *other)
{
	if (spa_list_is_empty(other))
		return;
	other->next->prev = list;
	other->prev->next = list->next;
	list->next->prev = other->prev;
	list->next = other->next;
}

static inline void spa_list_remove(struct spa_list *elem)
{
	elem->prev->next = elem->next;
	elem->next->prev = elem->prev;
}

#define spa_list_first(head, type, member)				\
	SPA_CONTAINER_OF((head)->next, type, member)

#define spa_list_last(head, type, member)				\
	SPA_CONTAINER_OF((head)->prev, type, member)

#define spa_list_append(list, item)					\
	spa_list_insert((list)->prev, item)

#define spa_list_prepend(list, item)					\
	spa_list_insert(list, item)

#define spa_list_is_end(pos, head, member)				\
	(&(pos)->member == (head))

#define spa_list_next(pos, member)					\
	SPA_CONTAINER_OF((pos)->member.next, __typeof__(*(pos)), member)

#define spa_list_prev(pos, member)					\
	SPA_CONTAINER_OF((pos)->member.prev, __typeof__(*(pos)), member)

#define spa_list_consume(pos, head, member)				\
	for ((pos) = spa_list_first(head, __typeof__(*(pos)), member);	\
	     !spa_list_is_empty(head);					\
	     (pos) = spa_list_first(head, __typeof__(*(pos)), member))

#define spa_list_for_each_next(pos, head, curr, member)			\
	for ((pos) = spa_list_first(curr, __typeof__(*(pos)), member);	\
	     !spa_list_is_end(pos, head, member);			\
	     (pos) = spa_list_next(pos, member))

#define spa_list_for_each_prev(pos, head, curr, member)			\
	for ((pos) = spa_list_last(curr, __typeof__(*(pos)), member);	\
	     !spa_list_is_end(pos, head, member);			\
	     (pos) = spa_list_prev(pos, member))

#define spa_list_for_each(pos, head, member)				\
	spa_list_for_each_next(pos, head, head, member)

#define spa_list_for_each_reverse(pos, head, member)			\
	spa_list_for_each_prev(pos, head, head, member)

#define spa_list_for_each_safe_next(pos, tmp, head, curr, member)	\
	for ((pos) = spa_list_first(curr, __typeof__(*(pos)), member);	\
	     (tmp) = spa_list_next(pos, member),				\
	     !spa_list_is_end(pos, head, member);			\
	     (pos) = (tmp))

#define spa_list_for_each_safe_prev(pos, tmp, head, curr, member)	\
	for ((pos) = spa_list_last(curr, __typeof__(*(pos)), member);	\
	     (tmp) = spa_list_prev(pos, member),				\
	     !spa_list_is_end(pos, head, member);			\
	     (pos) = (tmp))

#define spa_list_for_each_safe(pos, tmp, head, member)			\
	spa_list_for_each_safe_next(pos, tmp, head, head, member)

#define spa_list_for_each_safe_reverse(pos, tmp, head, member)		\
	spa_list_for_each_safe_prev(pos, tmp, head, head, member)

#define spa_list_cursor_start(cursor, head, member)                     \
        spa_list_prepend(head, &(cursor).member)

#define spa_list_for_each_cursor(pos, cursor, head, member)             \
        for((pos) = spa_list_first(&(cursor).member, __typeof__(*(pos)), member); \
            spa_list_remove(&(pos)->member),                            \
            spa_list_append(&(cursor).member, &(pos)->member),          \
            !spa_list_is_end(pos, head, member);                        \
            (pos) = spa_list_next(&(cursor), member))

#define spa_list_cursor_end(cursor, member)                             \
        spa_list_remove(&(cursor).member)

/**
 * \}
 */

#ifdef __cplusplus
}  /* extern "C" */
#endif

#endif /* SPA_LIST_H */