#include "garbage.h"

#define _GARBAGE_ERROR(m) \
	 ERROR("%s: Garbage error", m);

List *LIST_GARBAGE = NULL;

typedef struct {
   void (*p_func)(void*);
   void (*p_print)(void*);
   int *p_ref_count;
   void *p_2free;
   GarbageType type;
} _Garbage;

void
garbage_init() {
   LIST_GARBAGE = list_new();
}

void
garbage_destroy() {
   garbage_collect();
   if (!list_empty(LIST_GARBAGE)) {
      EPRINTF("The garbage collector still has %d registered items "
              " which don't have a zero ref count!\n",
              list_size(LIST_GARBAGE));

      _GARBAGE_ERROR("Garbage left");
   }

   list_delete(LIST_GARBAGE);
}

int
garbage_collect() {
   ListIterator *p_iter = listiterator_new(LIST_GARBAGE);
   List *p_list_garbage_new = list_new();
   int i_count = 0;

   while (listiterator_has_next(p_iter)) {
      _Garbage *p_garbage = listiterator_next(p_iter);

      if (p_garbage->p_ref_count == NULL || *p_garbage->p_ref_count <= 0) {
#ifdef DEBUG_GC
         printf("DEBUG::GC: Freeing ");
         if (NULL != p_garbage->p_print)
            (*p_garbage->p_print) (p_garbage->p_2free);
         else
            printf("0x%x\n", (int) p_garbage->p_2free);
#endif /* DEBUG_GC */
         (*p_garbage->p_func) (p_garbage->p_2free);
         free(p_garbage);
         ++i_count;

      } else {
         list_add_back(p_list_garbage_new, p_garbage);
      }
   }

   listiterator_delete(p_iter);

   list_delete(LIST_GARBAGE);
   LIST_GARBAGE = p_list_garbage_new;
#ifdef DEBUG_GC
   printf("DEBUG::GC: Freed %d items\n", i_count);
#endif /* DEBUG_GC */

   return (i_count);
}

void
garbage_add(void *p, GarbageType type) {
   garbage_add2(p, free, NULL, type);
}

void
garbage_add2(void *p,
             void (*p_func)(void*),
             int *p_ref_count,
             GarbageType type) {
   garbage_add3(p, free, p_func, NULL, type);
}

void
garbage_add3(void *p,
             void (*p_func)(void*),
             void (*p_print)(void*),
             int *p_ref_count,
             GarbageType type) {

   _Garbage *p_garbage = malloc(sizeof(_Garbage));

   p_garbage->p_2free = p;
   p_garbage->p_func = p_func;
   p_garbage->p_print = p_print;
   p_garbage->p_ref_count = p_ref_count;
   p_garbage->type = type;

   list_add_back(LIST_GARBAGE, p_garbage);
}

void
garbage_add_token(Token *p_token) {
   garbage_add3(p_token,
                token_delete_cb,
                token_print_cb,
                &p_token->i_ref_count, GC_TOKEN);
}