#include <stdlib.h>
#include <stdio.h>
#include "oware.h"


int value1(int side[])
{
  int v=side[houses];
  if (v>24) /* win */
    return 100;
  if (v==24) /* draw or better */
    return 50;
  return v;
}

int value(int thisside[], int otherside[])
{
  return value1(thisside)-value1(otherside);
}

/* best move when looking ahead from the position thisside/otherside
   for depth levels, and finally using value(); the return value is
   the best move (range 0-5), the value is passed back through vp;
   this function implements the negamax() algorithm */
int bestmove(int depth, int thisside[], int otherside[], int *vp)
{
  int best=-1;
  *vp=-1000;
  for (int i=0; i<houses; i++) {
    int ts1[houses+1], os1[houses+1];
    for (int j=0; j<=houses; j++) {
      ts1[j]=thisside[j];
      os1[j]=otherside[j];
    }
    if (plyfull(i,ts1,os1)) {
      int v=value(ts1,os1);
      if (depth>0 && -50<=v && v<=50) {
        (void)bestmove(depth-1,os1,ts1,&v);
        v = -v;
      }
#if 0
      printf("%*c%d %d%c\n",20-depth,' ',i+1,v,(v>*vp)?'*':' ');
#endif
      if (v>*vp) {
        *vp=v;
        best=i;
      }
    }
  }
  return best;
}

int main(int argc, char *argv[])
{
  int side1[houses+1];
  int side2[houses+1];
  int depth;
  int best,value;

  if (argc != 2*houses+4) {
    fprintf(stderr,"%s <depth> <side1-1>...<side1-6> <score1> <side2-1>...<side2-6> <score2>\n",argv[0]);
    exit(1);
  }
  depth=atoi(argv[1]);
  if (depth<0) {
    fprintf(stderr,"depth must be positive\n");
    exit(1);
  }
  if (cmdline2pos(argc-2,argv+2,side1,side2)==0) {
    fprintf(stderr,"this should not happen\n");
    exit(1);
  }
  printf("Position:\n");
  printboard(side1,side2);
  printf("\n");
  best=bestmove(depth, side1, side2, &value);
  printf("Best move (1-6): %d  Value: %d\n", best+1, value);
  return 0;
}