//
// Copyright 2024 Garrett D'Amore <garrett@damore.org>
//
// This software is supplied under the terms of the MIT License, a
// copy of which should be located in the distribution where this
// file was obtained (LICENSE.txt).  A copy of the license may also be
// found online at https://opensource.org/licenses/MIT.
//

#ifndef CORE_LIST_H
#define CORE_LIST_H

#include "core/defs.h"

// In order to make life easy, we just define the list structures
// directly, and let consumers directly inline structures.
typedef struct nni_list_node {
	struct nni_list_node *ln_next;
	struct nni_list_node *ln_prev;
} nni_list_node;

typedef struct nni_list {
	struct nni_list_node ll_head;
	size_t               ll_offset;
} nni_list;

extern void nni_list_init_offset(nni_list *list, size_t offset);

#define NNI_LIST_INIT(list, type, field) \
	nni_list_init_offset(list, offsetof(type, field))

// NNI_LIST_INITIALIZER is used to initialize structures at declaration time.
// The list argument is the structure being initialized and the type and
// offset determine where the node lives within each item.
#define NNI_LIST_INITIALIZER(list, type, field)          \
	{                                                \
		.ll_head.ln_next = &(list).ll_head,      \
		.ll_head.ln_prev = &(list).ll_head,      \
		.ll_offset       = offsetof(type, field) \
	}

#define NNI_LIST_NODE_INIT(node)                       \
	do {                                           \
		(node)->ln_prev = (node)->ln_next = 0; \
	} while (0)

extern void *nni_list_first(const nni_list *);
extern void *nni_list_last(const nni_list *);
extern void  nni_list_append(nni_list *, void *);
extern void  nni_list_prepend(nni_list *, void *);
extern void  nni_list_insert_before(nni_list *, void *, void *);
extern void  nni_list_insert_after(nni_list *, void *, void *);
extern void *nni_list_next(const nni_list *, void *);
extern void *nni_list_prev(const nni_list *, void *);
extern void  nni_list_remove(nni_list *, void *);
extern int   nni_list_active(nni_list *, void *);
extern int   nni_list_empty(nni_list *);
extern int   nni_list_node_active(nni_list_node *);
extern void  nni_list_node_remove(nni_list_node *);

#define NNI_LIST_FOREACH(l, it)                  \
	for (it = nni_list_first(l); it != NULL; \
	     it = nni_list_next(l, (void *) it))

#endif // CORE_LIST_H