#ifndef BTREE_H
#define BTREE_H

#include <stddef.h>

#define BTREE_DEGREE_DEFAULT 4

#define BTREE_SIZE_MIN 8
#define BTREE_SIZE_MAX 4096

#define BTREE_CMP_LT (-1)
#define BTREE_CMP_EQ (0)
#define BTREE_CMP_GT (1)

struct btree;
struct btree_iter_t;

/* elem_size: the size of the elements, typically `sizeof(struct <your struct>)`
 * t: degree of the btree, if you're in doubt, use `BTREE_SIZE_DEFAULT`
 * cmp: comparison function, in order to support any operations on the tree.
 *
 * This function just calls `btree_new_with_allocator` with `free` and `malloc`
 * as initializers.
 */
struct btree* btree_new(size_t elem_size, size_t t,
                        int (*cmp)(const void* a, const void* b));

/* Same as `btree_new`, except that it actually initializes a btree, but with
 * the given allocators.
 */
struct btree* btree_new_with_allocator(size_t elem_size, size_t t,
                                       int (*cmp)(const void* a, const void* b),
                                       void* (*alloc)(size_t),
                                       void (*dealloc)(void*));

void btree_free(struct btree** btree);

void* btree_search(struct btree* btree, void* elem);
void btree_insert(struct btree* btree, void* elem);
int btree_delete(struct btree* btree, void* elem);

void btree_print(struct btree* btree, void (*print_elem)(const void*));

void* btree_first(struct btree* btree);
void* btree_last(struct btree* btree);

size_t btree_size(struct btree* btree);

struct btree_iter_t* btree_iter_t_new(struct btree* tree);
void btree_iter_t_reset(struct btree* tree, struct btree_iter_t** it);

void* btree_iter(struct btree* tree, struct btree_iter_t* iter);

#endif