#include <stdlib.h>
#include "must.h"
#include "array.h"

////////////////////////////////////////////////////////////

void array_init(struct array *a) {
   a->v = NULL;
   a->num = a->max = 0;
}

struct array *array_create(void) {
   struct array *a;
   a = must_malloc(sizeof(*a));
   array_init(a);
   return a;
}

void array_cleanup(struct array *a) {
   free(a->v);
   a->v = NULL;
   a->num = a->max = 0;
}

void array_destroy(struct array *a) {
   array_cleanup(a);
   free(a);
}

////////////////////////////////////////////////////////////

/*
 * I wish there were a way to check that these were the same as the
 * inline versions, but apparently allowing such things to diverge is
 * a feature of C99. Bleh.
 */

unsigned array_num(const struct array *a) {
   return a->num;
}

void *array_get(const struct array *a, unsigned ix) {
   assert(ix < a->num);
   return a->v[ix];
}

void array_set(struct array *a, unsigned ix, void *ptr) {
   assert(ix < a->num);
   a->v[ix] = ptr;
}

////////////////////////////////////////////////////////////

unsigned array_add(struct array *a, void *ptr) {
   unsigned ix;

   ix = a->num;
   array_setsize(a, a->num+1);
   a->v[ix] = ptr;
   return ix;
}

void array_setsize(struct array *a, unsigned newnum) {
   unsigned newmax;
   void **newptr;

   if (newnum > a->max) {
      newmax = a->max;
      if (newmax == 0) {
	 newmax = 4;
      }
      while (newmax < newnum) {
	 newmax *= 2;
      }
      newptr = must_realloc(a->v, newmax*sizeof(void *));
      a->v = newptr;
      a->max = newmax;
   }

   a->num = newnum;

   /* Note: it's the user's responsibility to initialize the new space */
}

void array_nonulls(struct array *a) {
   unsigned i, j;

   for (i=j=0; i<a->num; i++) {
      if (a->v[i] != NULL) {
	 if (i != j) {
	    a->v[j] = a->v[i];
	 }
	 j++;
      }
   }

   a->num = j;
}

static int (*array_usersort)(void *a, void *b);

static int array_sortthunk(const void *av, const void *bv) {
   /* av and bv point to elements of the array */
   void *a = *(void *const *)av;
   void *b = *(void *const *)bv;
   return array_usersort(a, b);
}

void array_sort(struct array *a, int (*f)(void *a, void *b)) {
   array_usersort = f;
   qsort(a->v, a->num, sizeof(void *), array_sortthunk);
}