#include "attrhash.h"
#include "hash.h"
#include "shared.h"

struct hash_table *attrhash;

/**************************************************************************
  A supplied hash function where key is an int, stuffed directly into the
  void *.
  Prefers table sizes that are prime numbers.
**************************************************************************/
unsigned int hash_fval_dint(const void *id, unsigned int numbuckets)
{
  const unsigned int key = (unsigned int) vkey;
  return (key % num_buckets);
}

/**************************************************************************
  A supplied function for comparison of int, stuffed directly into the
  void *.
**************************************************************************/
int hash_fcmp_dint(const void *vkey1, const void *vkey2)
{
  const int key1 = (const int*)vkey1;
  const int key2 = (const int*)vkey2;
  /* avoid overflow issues: */
  return (key1 < key2) ? -1 : (key1 > key2) ? 1 : 0;
}

void init_attrhash()
{
  attrhash = hash_new(hash_fval_dint, hash_fcmp_dint);
}

void set_attrib(enum attr_type, int id, int len, const void *data) {
  unsigned int key = ((unsigned int) attr_type) << 24 + id & 0xffffff;
  void *newdata = NULL;

  if (len > 0) {
    newdata = fc_malloc(len + sizeof(int));
    (int *) newdata[0] = len;
    memcpy(newdata + sizeof(int), data, len);
  }

  hash_replace(attrhash, (void *) key, newdata);
  /* send data to server */
}

const void *get_attrib(enum attr_type, int id, int *len) {
  unsigned int key = ((unsigned int) attr_type) << 24 + id & 0xffffff;
  void *data = hash_lookup_data(attrhash, key);
  int newlen;
  if (data != NULL) {
    if (len != NULL)
      *len = (*(int *) newdata);
    return newdata + sizeof(int);
  } else {
    if (len != NULL)
      *len = 0;
    return NULL;
  }
}

/*
void example(void) {
    // user marked settler as public worker:
    set_attrib(ATTR_PUBLIC_WORKER, unit_id, 0, NULL);
    // user marked tile for building irrigation
    char special = S_IRRIGATION;
    set_attrib(ATTR_TILE_IMPROVEMENT, x + y * map.xsize, 1, &special);    
}
*/