/*  DEKMGR.C      deck manager
 */

#include "local.h"
#include "bj.h"
#include "dekmgr.h"

#define NCARDS (4 * 52)

static short deck[NCARDS] = {0};    /* the deck */
static short nc = 0;                /* subscript of next card */
static short shufpt = 0;            /* subscript of shuffle point */

/*  deklow  -  is deck at or past shuffle point ?
 */
bool  deklow()
{
   return (shufpt <= nc);
}

/* opndck  -  initialize the deck
 */
void  opndek()
{
   short varnum();
   void  shuffl();
   void  srand();

   short i;
   short low;

   for (low = 0; low < NCARDS; low += 52)
      for (i = 0; i < 52; ++i)
         deck[i + low] = i;
   srand((unsigned)varnum());
   shuffl();
}

/* shuffl  -  shuffle the deck
 */
void  shuffl()
{
   short t;             /* temporary for swap */
   short i;             /* index for loop over cards */
   short j;             /* index for swap */
   short nfrom();       /* fn to produce random number */

   for (i = 0; i < NCARDS; ++i) {
      j = nfrom(i, NCARDS - 1);
      t = deck[j], deck[j] = deck[i], deck[i] = t;
   }
   shufpt = nfrom(NCARDS - 52, NCARDS - 36);
   nc = 0;
   printf("Shuffle\n");
}

/* tkcard  -  take a card
 */
short tkcard()
{
   void  shuffl();

   if (NCARDS <= nc) shuffl();

   return(deck[nc++]);
}

/* varnum  -  returns a varying startoff number
 */
short varnum()
{
   int rand();

   return((short)rand());
}