#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <grass/G3d.h>
#include "G3d_intern.h"

/*---------------------------------------------------------------------------*/
#ifndef GRASS_G3D_H
typedef struct {

  int nofNames;
  int *index;
  char *active;
  int lastName;
  int lastIndex;
  int lastIndexActive;

} G3d_cache_hash;
#endif
/*---------------------------------------------------------------------------*/

void
G3d_cache_hash_reset  (G3d_cache_hash *h)

{
  int i;

  for (i = 0; i < h->nofNames; i++) h->active[i] = 0;

  h->lastIndexActive = 0;
}

/*---------------------------------------------------------------------------*/

void
G3d_cache_hash_dispose  (G3d_cache_hash *h)

{
  if (h == NULL) return;

  if (h->index != NULL) G3d_free (h->index);
  if (h->active != NULL) G3d_free (h->active);
  G3d_free (h);
}

/*---------------------------------------------------------------------------*/

void *
G3d_cache_hash_new  (int nofNames)

{
  G3d_cache_hash *tmp;

  tmp = G3d_malloc (sizeof (G3d_cache_hash));
  if (tmp == NULL) {
    G3d_error ("G3d_cache_hash_new: error in G3d_malloc");
    return (void *) NULL;
  }

  tmp->nofNames = nofNames;
  tmp->index = G3d_malloc (sizeof (int) * tmp->nofNames);
  tmp->active = G3d_malloc (sizeof (char) * tmp->nofNames);
  if ((tmp->index == NULL) || (tmp->active == NULL)) {
    G3d_cache_hash_dispose (tmp);
    G3d_error ("G3d_cache_hash_new: error in G3d_malloc");
    return (void *) NULL;
  }

  G3d_cache_hash_reset (tmp);

  return tmp;
}

/*---------------------------------------------------------------------------*/

void
G3d_cache_hash_remove_name  (G3d_cache_hash *h, int name)

{
  if (name >= h->nofNames)
    G3d_fatalError ("G3d_cache_hash_remove_name: name out of range");

  if (h->active[name] == 0)
    G3d_fatalError ("G3d_cache_hash_remove_name: name not in hashtable");

  h->active[name] = 0;
  if (name == h->lastName) h->lastIndexActive = 0;
}

/*---------------------------------------------------------------------------*/

void
G3d_cache_hash_load_name  (G3d_cache_hash *h, int name, int index)

{
  if (name >= h->nofNames)
    G3d_fatalError ("G3d_cache_hash_load_name: name out of range");

  if (h->active[name] != 0)
    G3d_fatalError ("G3d_cache_hash_load_name: name already in hashtable");

  h->index[name] = index;
  h->active[name] = 1;
}

/*---------------------------------------------------------------------------*/

int
G3d_cache_hash_name2index  (G3d_cache_hash *h, int name)

{
  int index;
  
  if (h->lastIndexActive)
    if (h->lastName == name) return h->lastIndex;

  if (! h->active[name]) return -1;

  index = h->index[name];

  h->lastName = name;
  h->lastIndex = index;
  h->lastIndexActive = 1;

  return index;
}