#ifndef LIBCGDS_LIST_H
#define LIBCGDS_LIST_H 1

#include <stddef.h>

/*  Singly-linked list
 *  --------->      --------->
 *  |Next|...   =>  |Next|...   => ...
 *  --------->      --------->
 *  Elements of linked list must have sllist_node struct at front
 *  sllist functions take pointer to sllist head ptr
 * */
struct sllist_node {
    struct sllist_node *next;
};

/*  Pushes element into first index of sllist
 *  Element must have sllist_node as first member
 *  Replaces pointer at head with new head
 * */
void __sll_push(struct sllist_node **head, struct sllist_node *data);
#define sll_push(a, b) __sll_push((struct sllist_node**)a, (struct sllist_node*)b)

void __sll_pushback(struct sllist_node **head, struct sllist_node *data);
#define sll_pushback(a, b) __sll_pushback((struct sllist_node**)a, (struct sllist_node*)b)

/*  Pops element 0 from list
 *  Returns element 0
 *  Sets new head
 * */
void *__sll_pop(struct sllist_node **head);
#define sll_pop(a) __sll_pop((struct sllist_node**)a)

/*  Gets element of sllist at i
 *  Element must have sllist_node as first member
 *  Head can be in middle of list to get n elements after
 * */
void *__sll_at(struct sllist_node **head, size_t i);
#define sll_at(a, b) __sll_at((struct sllist_node**)a, b)

/*  Removes element of sllist at i
 *  Moves leading elements down
 * */
void __sll_remove(struct sllist_node **head, size_t i);
#define sll_remove(a, b) __sll_remove((struct sllist_node**)a, b)

/*  Removes element from list
 *  Moves leading elements down
 * */
void __sll_delete(struct sllist_node **head, struct sllist_node *node);
#define sll_delete(a, b) __sll_delete((struct sllist_node**)a, (struct sllist_node*)b)

/*  Pushes val into list at i, moving following elements forward starting at replaced
 *  Sets new head if i == 0
 * */
void __sll_insert(struct sllist_node **head, struct sllist_node *val, size_t i);
#define sll_insert(a, b, c) __sll_insert((struct sllist_node**)a, (struct sllist_node*)b, c)

#define sll_foreach(t, a, b) for(t a = *b; a; a = (t)(((struct sllist_node*)a)->next))

#endif