/*      $OpenBSD: snova.c,v 1.8 2016/01/07 14:37:51 mestre Exp $        */
/*      $NetBSD: snova.c,v 1.3 1995/04/22 10:59:29 cgd 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 <stdio.h>
#include <unistd.h>

#include "trek.h"

/*
**  CAUSE SUPERNOVA TO OCCUR
**
**      A supernova occurs.  If 'ix' < 0, a random quadrant is chosen;
**      otherwise, the current quadrant is taken, and (ix, iy) give
**      the sector quadrants of the star which is blowing up.
**
**      If the supernova turns out to be in the quadrant you are in,
**      you go into "emergency override mode", which tries to get you
**      out of the quadrant as fast as possible.  However, if you
**      don't have enough fuel, or if you by chance run into something,
**      or some such thing, you blow up anyway.  Oh yeh, if you are
**      within two sectors of the star, there is nothing that can
**      be done for you.
**
**      When a star has gone supernova, the quadrant becomes uninhab-
**      itable for the rest of eternity, i.e., the game.  If you ever
**      try stopping in such a quadrant, you will go into emergency
**      override mode.
*/

void
snova(int x, int y)
{
        int             qx, qy;
        int             ix, iy = 0;
        int             f, n;
        int             dx, dy;
        struct quad     *q;

        f = 0;
        ix = x;
        if (ix < 0)
        {
                /* choose a quadrant */
                while (1)
                {
                        qx = ranf(NQUADS);
                        qy = ranf(NQUADS);
                        q = &Quad[qx][qy];
                        if (q->stars > 0)
                                break;
                }
                if (Ship.quadx == qx && Ship.quady == qy)
                {
                        /* select a particular star */
                        n = ranf(q->stars);
                        for (ix = 0; ix < NSECTS; ix++)
                        {
                                for (iy = 0; iy < NSECTS; iy++)
                                        if (Sect[ix][iy] == STAR || Sect[ix][iy] == INHABIT)
                                                if ((n -= 1) <= 0)
                                                        break;
                                if (n <= 0)
                                        break;
                        }
                        f = 1;
                }
        }
        else
        {
                /* current quadrant */
                iy = y;
                qx = Ship.quadx;
                qy = Ship.quady;
                q = &Quad[qx][qy];
                f = 1;
        }
        if (f)
        {
                /* supernova is in same quadrant as Enterprise */
                printf("\a\nRED ALERT: supernova occuring at %d,%d\n", ix, iy);
                dx = ix - Ship.sectx;
                dy = iy - Ship.secty;
                if (dx * dx + dy * dy <= 2)
                {
                        printf("***  Emergency override attem");
                        sleep(1);
                        printf("\n");
                        lose(L_SNOVA);
                }
                q->scanned = 1000;
        }
        else
        {
                if (!damaged(SSRADIO))
                {
                        q->scanned = 1000;
                        printf("\nUhura: Captain, Starfleet Command reports a supernova\n");
                        printf("  in quadrant %d,%d.  Caution is advised\n", qx, qy);
                }
        }

        /* clear out the supernova'ed quadrant */
        dx = q->klings;
        dy = q->stars;
        Now.klings -= dx;
        if (x >= 0)
        {
                /* Enterprise caused supernova */
                Game.kills += dy;
                if (q->bases)
                        killb(qx, qy);
                Game.killk += dx;
        }
        else
                if (q->bases)
                        killb(qx, qy);
        killd(qx, qy, (x >= 0));
        q->stars = -1;
        q->klings = 0;
        if (Now.klings <= 0)
        {
                printf("Lucky devil, that supernova destroyed the last klingon\n");
                win();
        }
}