#ifndef foosydneyllistfoo
#define foosydneyllistfoo

#include "macro.h"

#define SA_LLIST_HEAD(t,head)                                           \
    t* head

#define SA_LLIST_ITEM(t,name)                                           \
    t* name##_prev, *name##_next

#define SA_LLIST_HEAD_INIT(t,head)                                      \
    (head) = (t*) NULL

#define SA_LLIST_ITEM_INIT(t,name,item)                                 \
    do {                                                                \
        t *_item = (item);                                              \
        sa_assert(_item);                                               \
        _item->name##_prev = _item->name##_next = NULL;                 \
    } while(0)

#define SA_LLIST_PREPEND(t,name,head,item)                              \
    do {                                                                \
        t **_head = &(head), *_item = (item);                           \
        sa_assert(_item);                                               \
        if ((_item->name##_next = *_head))                              \
            _item->name##_next->name##_prev = _item;                    \
        _item->name##_prev = NULL;                                      \
        *_head = _item;                                                 \
    } while (0)

#define SA_LLIST_INSERT_BEFORE(t,name,head,at,item)                     \
    do {                                                                \
        t **_head = &(head), *_item = (item), *_at = (at);              \
        sa_assert(_item);                                               \
        sa_assert(_at);                                                 \
        if ((_item->name##_prev = _at->name##_prev)) {                  \
            sa_assert(_item->name##_prev->name##_next == _at);          \
            _item->name##_prev->name##_next = _item;                    \
        } else {                                                        \
            sa_assert(*_head == _at);                                   \
            *_head = _item;                                             \
        }                                                               \
        _item->name##_next = _at;                                       \
        _at->name##_prev = _item;                                       \
    } while (0)

#define SA_LLIST_INSERT_AFTER(t,name,head,at,item)                      \
    do {                                                                \
        t *_item = (item), *_at = (at);                                 \
        sa_assert(_item);                                               \
        sa_assert(_at);                                                 \
        if ((_item->name##_next = _at->name##_next)) {                  \
            sa_assert(_item->name##_next->name##_prev == _at);          \
            _item->name##_next->name##_prev = _item;                    \
        }                                                               \
        _item->name##_prev = _at;                                       \
        _at->name##_next = _item;                                       \
    } while (0)

#define SA_LLIST_REMOVE(t,name,head,item)                               \
    do {                                                                \
        t **_head = &(head), *_item = (item);                           \
        sa_assert(_item);                                               \
        if (_item->name##_next)                                         \
            _item->name##_next->name##_prev = _item->name##_prev;       \
        if (_item->name##_prev)                                         \
            _item->name##_prev->name##_next = _item->name##_next;       \
        else {                                                          \
            sa_assert(*_head == _item);                                 \
            *_head = _item->name##_next;                                \
        }                                                               \
        _item->name##_next = _item->name##_prev = NULL;                 \
    } while(0)

#endif