/*      $NetBSD: one.c,v 1.9 2012/10/13 19:19:39 dholland Exp $ */

/*
* Copyright (c) 1980, 1993
*      The Regents of the University of California.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)one.c       8.1 (Berkeley) 5/31/93";
#else
__RCSID("$NetBSD: one.c,v 1.9 2012/10/13 19:19:39 dholland Exp $");
#endif
#endif /* not lint */

#include "back.h"

static int checkd(struct move *, int);
static int last(void);

int
makmove(struct move *mm, int i)
{
       int     n, d;
       int     max;

       d = mm->d0;
       n = abs(mm->g[i] - mm->p[i]);
       max = (*offptr < 0 ? 7 : last());
       if (board[mm->p[i]] * cturn <= 0)
               return (checkd(mm, d) + 2);
       if (mm->g[i] != home && board[mm->g[i]] * cturn < -1)
               return (checkd(mm, d) + 3);
       if (i || mm->D0 == mm->D1) {
               if (n == max ? mm->D1 < n : mm->D1 != n)
                       return (checkd(mm, d) + 1);
       } else {
               if (n == max ? mm->D0 < n && mm->D1 < n : mm->D0 != n && mm->D1 != n)
                       return (checkd(mm, d) + 1);
               if (n == max ? mm->D0 < n : mm->D0 != n) {
                       if (mm->d0)
                               return (checkd(mm, d) + 1);
                       mswap(mm);
               }
       }
       if (mm->g[i] == home && *offptr < 0)
               return (checkd(mm, d) + 4);
       mm->h[i] = 0;
       board[mm->p[i]] -= cturn;
       if (mm->g[i] != home) {
               if (board[mm->g[i]] == -cturn) {
                       board[home] -= cturn;
                       board[mm->g[i]] = 0;
                       mm->h[i] = 1;
                       if (abs(bar - mm->g[i]) < 7) {
                               (*inopp)--;
                               if (*offopp >= 0)
                                       *offopp -= 15;
                       }
               }
               board[mm->g[i]] += cturn;
               if (abs(home - mm->g[i]) < 7 && abs(home - mm->p[i]) > 6) {
                       (*inptr)++;
                       if (*inptr + *offptr == 0)
                               *offptr += 15;
               }
       } else {
               (*offptr)++;
               (*inptr)--;
       }
       return (0);
}

void
moverr(struct move *mm, int i)
{
       int     j;

       if (tflag)
               curmove(20, 0);
       else
               writec('\n');
       writel("Error:  ");
       for (j = 0; j <= i; j++) {
               wrint(mm->p[j]);
               writec('-');
               wrint(mm->g[j]);
               if (j < i)
                       writec(',');
       }
       writel("... ");
       movback(mm, i);
}


static int
checkd(struct move *mm, int d)
{
       if (mm->d0 != d)
               mswap(mm);
       return (0);
}

static int
last(void)
{
       int     i;

       for (i = home - 6 * cturn; i != home; i += cturn)
               if (board[i] * cturn > 0)
                       return (abs(home - i));
       return (-1);
}

void
movback(struct move *mm, int i)
{
       int     j;

       for (j = i - 1; j >= 0; j--)
               backone(mm, j);
}

void
backone(struct move *mm, int i)
{
       board[mm->p[i]] += cturn;
       if (mm->g[i] != home) {
               board[mm->g[i]] -= cturn;
               if (abs(mm->g[i] - home) < 7 && abs(mm->p[i] - home) > 6) {
                       (*inptr)--;
                       if (*inptr + *offptr < 15 && *offptr >= 0)
                               *offptr -= 15;
               }
       } else {
               (*offptr)--;
               (*inptr)++;
       }
       if (mm->h[i]) {
               board[home] += cturn;
               board[mm->g[i]] = -cturn;
               if (abs(bar - mm->g[i]) < 7) {
                       (*inopp)++;
                       if (*inopp + *offopp == 0)
                               *offopp += 15;
               }
       }
}