#ifndef APFL_HASHMAP_H
#define APFL_HASHMAP_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>

#define APFL_HASH_FNV1A_INIT 14695981039346656037U // offset_basis for 64bit FNV-1(a)

// TODO: <stdint.h> is not required to provide uint64_t
typedef uint64_t apfl_hash;

typedef struct apfl_hashmap_struct *apfl_hashmap;

typedef struct apfl_hashmap_cursor_struct *apfl_hashmap_cursor;

struct apfl_hashmap_callbacks {
    void *opaque;

    // Compare keys a and b. If not provided, they will be compared with memcmp
    bool      (*keys_eq)      (void *opaque, const void *a, const void *b);

    // Calculate a hash value of a key.
    // If not provided, a hash will be calculated based on the bytes of the key.
    apfl_hash (*calc_hash)    (void *opaque, const void *key);

    // Destroy a key. Does nothing, if not provided.
    void      (*destroy_key)  (void *opaque, void *key);

    // Destroy a value. Does nothing, if not provided.
    void      (*destroy_value)(void *opaque, void *value);

    // Copies a key. Returns true on success, false on failure.
    // If not provided, the bytes will be copied with memcpy.
    bool      (*copy_key)     (void *opaque, void *dest, void *src);

    // Copies a value. Returns true on success, false on failure.
    // If not provided, the bytes will be copied with memcpy.
    bool      (*copy_value)   (void *opaque, void *dest, void *src);
};

apfl_hash apfl_hash_fnv1a_add(const void *, size_t len, apfl_hash);
apfl_hash apfl_hash_fnv1a(const void *, size_t len);

apfl_hashmap apfl_hashmap_new(struct apfl_hashmap_callbacks, size_t keysize, size_t valsize);
void apfl_hashmap_delete(apfl_hashmap, const void *key);
bool apfl_hashmap_get(const apfl_hashmap, const void *key, void *value);
bool apfl_hashmap_set(apfl_hashmap, void *key, void *value);
size_t apfl_hashmap_count(const apfl_hashmap);
void apfl_hashmap_destroy(apfl_hashmap);

apfl_hashmap apfl_hashmap_copy(apfl_hashmap src);

#define apfl_hashmap_isset(m, k) (apfl_hashmap_get((m), (k), NULL))

apfl_hashmap_cursor apfl_hashmap_get_cursor(apfl_hashmap);
bool apfl_hashmap_cursor_is_end(apfl_hashmap_cursor);
void apfl_hashmap_cursor_next(apfl_hashmap_cursor);
bool apfl_hashmap_cursor_get_key(apfl_hashmap_cursor, void *key);
bool apfl_hashmap_cursor_get_value(apfl_hashmap_cursor, void *value);

#define apfl_hashmap_cursor_destroy(cur) (free(cur))

#ifdef __cplusplus
}
#endif

#endif