/*      $NetBSD: misc.c,v 1.18 2009/03/14 19:35:13 dholland Exp $       */

/*
 * Copyright (c) 1983, 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[] = "@(#)misc.c      8.2 (Berkeley) 4/28/95";
#else
__RCSID("$NetBSD: misc.c,v 1.18 2009/03/14 19:35:13 dholland Exp $");
#endif
#endif /* not lint */

#include <ctype.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include "extern.h"
#include "pathnames.h"

#define distance(x,y) \
        (abs(x) >= abs(y) ? abs(x) + abs(y)/2 : abs(y) + abs(x)/2)

static int angle(int, int);

/* XXX */
int
range(struct ship *from, struct ship *to)
{
        int bow1r, bow1c, bow2r, bow2c;
        int stern1r, stern1c, stern2c, stern2r;
        int bb, bs, sb, ss, result;

        if (!to->file->dir)
                return -1;
        stern1r = bow1r = from->file->row;
        stern1c = bow1c = from->file->col;
        stern2r = bow2r = to->file->row;
        stern2c = bow2c = to->file->col;
        result = bb = distance(bow2r - bow1r, bow2c - bow1c);
        if (bb < 5) {
                stern2r += dr[to->file->dir];
                stern2c += dc[to->file->dir];
                stern1r += dr[from->file->dir];
                stern1c += dc[from->file->dir];
                bs = distance((bow2r - stern1r), (bow2c - stern1c));
                sb = distance((bow1r - stern2r), (bow1c - stern2c));
                ss = distance((stern2r - stern1r) ,(stern2c - stern1c));
                result = min(bb, min(bs, min(sb, ss)));
        }
        return result;
}

struct ship *
closestenemy(struct ship *from, int side, int anyship)
{
        struct ship *sp;
        char a;
        int olddist = 30000, dist;
        struct ship *closest = 0;

        a = capship(from)->nationality;
        foreachship(sp) {
                if (sp == from)
                        continue;
                if (sp->file->dir == 0)
                        continue;
                if (a == capship(sp)->nationality && !anyship)
                        continue;
                if (side && gunsbear(from, sp) != side)
                        continue;
                dist = range(from, sp);
                if (dist < olddist) {
                        closest = sp;
                        olddist = dist;
                }
        }
        return closest;
}

static int
angle(int Dr, int Dc)
{
        int i;

        if (Dc >= 0 && Dr > 0)
                i = 0;
        else if (Dr <= 0 && Dc > 0)
                i = 2;
        else if (Dc <= 0 && Dr < 0)
                i = 4;
        else
                i = 6;
        Dr = abs(Dr);
        Dc = abs(Dc);
        if ((i == 0 || i == 4) && Dc * 2.4 > Dr) {
                i++;
                if (Dc > Dr * 2.4)
                        i++;
        } else if ((i == 2 || i == 6) && Dr * 2.4 > Dc) {
                i++;
                if (Dr > Dc * 2.4)
                        i++;
        }
        return i % 8 + 1;
}

/* checks for target bow or stern */
int
gunsbear(struct ship *from, struct ship *to)
{
        int Dr, Dc, i;
        int ang;

        Dr = from->file->row - to->file->row;
        Dc = to->file->col - from->file->col;
        for (i = 2; i; i--) {
                if ((ang = angle(Dr, Dc) - from->file->dir + 1) < 1)
                        ang += 8;
                if (ang >= 2 && ang <= 4)
                        return 'r';
                if (ang >= 6 && ang <= 7)
                        return 'l';
                Dr += dr[to->file->dir];
                Dc += dc[to->file->dir];
        }
        return 0;
}

/* returns true if fromship is shooting at onship's starboard side */
int
portside(struct ship *from, struct ship *on, int quick)
{
        int ang;
        int Dr, Dc;

        Dr = from->file->row - on->file->row;
        Dc = on->file->col - from->file->col;
        if (quick == -1) {
                Dr += dr[on->file->dir];
                Dc += dc[on->file->dir];
        }
        ang = angle(Dr, Dc);
        if (quick != 0)
                return ang;
        ang = (ang + 4 - on->file->dir - 1) % 8 + 1;
        return ang < 5;
}

int
colours(struct ship *sp)
{
        char flag = '\0';

        if (sp->file->struck)
                flag = '!';
        if (sp->file->explode)
                flag = '#';
        if (sp->file->sink)
                flag = '~';
        if (sp->file->struck)
                return flag;
        flag = *countryname[capship(sp)->nationality];
        return sp->file->FS ? flag : tolower((unsigned char)flag);
}

void
logger(struct ship *s)
{
        FILE *fp;
        int persons;
        int n;
        struct logs log[NLOG];
        float net;
        struct logs *lp;

        setegid(egid);
        if ((fp = fopen(_PATH_LOGFILE, "r+")) == NULL) {
                setegid(gid);
                return;
        }
        setegid(gid);
#ifdef LOCK_EX
        if (flock(fileno(fp), LOCK_EX) < 0)
                return;
#endif
        net = (float)s->file->points / s->specs->pts;
        persons = getw(fp);
        n = fread(log, sizeof(struct logs), NLOG, fp);
        for (lp = &log[n]; lp < &log[NLOG]; lp++)
                lp->l_name[0] = lp->l_uid = lp->l_shipnum
                        = lp->l_gamenum = lp->l_netpoints = 0;
        rewind(fp);
        if (persons < 0)
                putw(1, fp);
        else
                putw(persons + 1, fp);
        for (lp = log; lp < &log[NLOG]; lp++)
                if (net > (float)lp->l_netpoints
                    / scene[lp->l_gamenum].ship[lp->l_shipnum].specs->pts) {
                        fwrite(log, sizeof (struct logs), lp - log, fp);
                        strcpy(log[NLOG-1].l_name, s->file->captain);
                        log[NLOG-1].l_uid = getuid();
                        log[NLOG-1].l_shipnum = s->file->index;
                        log[NLOG-1].l_gamenum = game;
                        log[NLOG-1].l_netpoints = s->file->points;
                        fwrite(&log[NLOG-1], sizeof (struct logs), 1, fp);
                        fwrite(lp, sizeof (struct logs), &log[NLOG-1] - lp, fp);
                        break;
                }
#ifdef LOCK_EX
        flock(fileno(fp), LOCK_UN);
#endif
        fclose(fp);
}