#pragma once

#include "typecheck.h"

struct intrusive_list {
  struct intrusive_list *next;
  struct intrusive_list *prev;
};

static inline void intrusive_list_init_empty(struct intrusive_list *head) {
  head->next = head;
  head->prev = head;
}

static inline void intrusive_list_del(struct intrusive_list *node) {
  struct intrusive_list old_node;

  old_node = *node;
  node->prev->next = old_node.next;
  node->next->prev = old_node.prev;
}

static inline void intrusive_list_add(
  struct intrusive_list *add_after,
  struct intrusive_list *new_node)
{
  new_node->prev = add_after;
  new_node->next = add_after->next;
  new_node->prev->next = new_node;
  new_node->next->prev = new_node;
}

#define INTRUSIVE_LIST_FOR_EACH(ITER, NEXT, HEAD) \
  for (                                           \
    CHECK_TYPE(struct intrusive_list *, HEAD),    \
      (ITER) = (HEAD)->next,                      \
      (NEXT) = (ITER)->next;                      \
    (ITER) != (HEAD);                             \
    (ITER) = (NEXT), (NEXT) = (ITER)->next)

#define INTRUSIVE_LIST_FOR_EACH_NO_REMOVE(ITER, HEAD) \
  for (                                               \
    CHECK_TYPE(struct intrusive_list *, HEAD),        \
      (ITER) = (HEAD)->next;                          \
    (ITER) != (HEAD);                                 \
    (ITER) = (ITER)->next)