#include <stdarg.h>
#include <string.h>
#include <unistd.h>

#include <gprolog.h>

const char *gl_types;
va_list gl_ap;

void get_args(PlTerm *t)
{
  int n;
  const char *types;
  PlTerm *args, *parg;
  va_list ap = gl_ap;

  n = strlen(gl_types);
  args = (PlTerm *)malloc(n * sizeof(PlTerm));
  if (!args)
    exit(1);

  for (parg = args, types = gl_types; *types; parg++, types++)
    switch (*types) {
    case 'c':
      *parg = Mk_Codes(va_arg(ap, char *));
      break;
    default:
      (void)va_arg(ap, void *);
      *parg = Mk_Variable();
      break;
    }

  *t = Mk_Proper_List(n, args);
  free(args);
}

void put_args(PlTerm t)
{
  int n;
  const char *types;
  PlTerm *args, *parg;
  va_list ap = gl_ap;

  n = strlen(gl_types);
  args = (PlTerm *)malloc(n * sizeof(PlTerm));
  if (!args)
    exit(1);

  Rd_Proper_List(t, args);

  for (parg = args, types = gl_types; *types; parg++, types++)
    switch (*types) {
    case 'C':
      *va_arg(ap, char **) = strdup(Rd_Codes(*parg));
      break;
    default:
      (void)va_arg(ap, void *);
      *parg = Mk_Variable();
      break;
    }

  free(args);
}

int call_prolog(const char *functor, const char *types, ...)
{
  PlTerm arg;
  va_list ap;
  int ret;

  arg = Mk_String((char *)functor);
  gl_types = types;
  va_start(ap, types);
  gl_ap = ap;
  ret = (Pl_Query_Start(Find_Atom("call_prolog"), 1, &arg, TRUE) == PL_SUCCESS);
  Pl_Query_End(PL_RECOVER);
  va_end(ap);
  return ret;
}

int main(int argc, char *argv[])
{
  int i;

  Start_Prolog(0, 0);

  for (i = 0; i < 1000000; i++) {
    char buf[30];
    char *res;

    sprintf(buf, "%d", i);
    call_prolog("reverse", "cC", buf, &res);
    printf("%s\n", res);
    free(res);
  }

  Stop_Prolog();

  return 0;
}