#ifndef HT_H
#define HT_H
#include "util.h"

enum { HT_INIT_CAP = 257 };

/* TODO: Modify the probing algorithm.  Imitate the algorithm used by
   python's hash tables.  The source code of the python dict object
   can be found in the following URL:

   <https://hg.python.org/cpython/file/52f68c95e025/Objects/dictobject.c#l33> */

/* TODO: Generalize the type of the keys, so that we can use anything
   as the key.  The type of the keys should satisfy the following
   conditions.

   - Hash-able: We must know how to produce the hash value of a
     key.

   - Comparable: We must know how to compare two keys, in order to
     know if two keys are "equal". */

/* type for a hash function */
typedef NUM (*hash_func_t) (void *key);

/* comparison function type */
typedef BOOL (*compare_func_t) (void *keya, void *keyb);

struct ht_s {
  NUM *keys;
  void **values;
  NUM *indices;
  UNUM capability;
  /* REVIEW: What is the purpose of SIZE? */
  /* ANSWER: For looping over keys / values. */
  int size;
  /* hash_func_t hf;
   * compare_func_t cf; */
};

typedef struct ht_s ht;

/* On error return NULL */
ht *new_ht(UNUM size);

enum HT_DESTROY_FLAG_e {
  DESTROY_NONE_NO_SELF,
  DESTROY_NONE_SELF,
  DESTROY_EVERY_NO_SELF,
  DESTROY_EVERY_SELF,
  DESTROY_FIRST_NO_SELF,
  DESTROY_FIRST_SELF
};

typedef enum HT_DESTROY_FLAG_e HT_DESTROY_FLAG;
void destroy_ht(ht * restrict htp, HT_DESTROY_FLAG flag);

BOOL ht_insert(ht *htp, NUM key, void *value);

P_ATTR NUM ht_size(CCR_MOD(ht *) htp);

P_ATTR void **ht_values(CCR_MOD(ht *) htp);

P_ATTR NUM *ht_keys(CCR_MOD(ht *) htp);

/* If FLAG is non-zero, also free the value pointer. */
BOOL ht_delete(ht * const restrict htp, NUM key, int flag);

P_ATTR void *ht_find(CCR_MOD(ht *) htp, NUM key);

#endif