/*      $OpenBSD: snake.c,v 1.34 2019/06/28 13:32:52 deraadt Exp $      */
/*      $NetBSD: snake.c,v 1.8 1995/04/29 00:06:41 mycroft 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.
 */

/*
 * snake - crt hack game.
 *
 * You move around the screen with arrow keys trying to pick up money
 * without getting eaten by the snake.  hjkl work as in vi in place of
 * arrow keys.  You can leave at the exit any time.
 */

#include <curses.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <math.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>

#ifdef  DEBUG
#define cashvalue       (loot-penalty)/25
#else
#define cashvalue       chunk*(loot-penalty)/25
#endif

struct point {
        int col, line;
};

#define same(s1, s2)    ((s1)->line == (s2)->line && (s1)->col == (s2)->col)

#define PENALTY 10      /* % penalty for invoking spacewarp     */

#define ME              'I'
#define SNAKEHEAD       'S'
#define SNAKETAIL       's'
#define TREASURE        '$'
#define GOAL            '#'

#define TOPN    10      /* top scores to print if you lose */
#define SCORES_ENTRIES (TOPN + 1)

#define pchar(point, c) mvaddch((point)->line + 1, (point)->col + 1, (c))
/* Can't use terminal timing to do delay, in light of X */
#define delay(t)        usleep((t) * 50000)
/* Delay units are 1/20 s */

struct point you;
struct point money;
struct point finish;
struct point snake[6];

int      lcnt, ccnt;    /* user's idea of screen size */
int      chunk;         /* amount of money given at a time */
int      loot, penalty;
int      moves;
int      fast = 1;

struct highscore {
        char    name[LOGIN_NAME_MAX];
        short   score;
} scores[SCORES_ENTRIES];
int      nscores;

char     scorepath[PATH_MAX];
FILE    *sf;
int      rawscores;

#ifdef LOGGING
FILE    *logfile;
char     logpath[PATH_MAX];
#endif

void    chase(struct point *, struct point *);
int     chk(struct point *);
void    drawbox(void);
void    length(int);
void    mainloop(void);
int     post(int, int);
int     pushsnake(void);
int     readscores(int);
void    setup(void);
void    snap(void);
void    snrand(struct point *);
void    snscore(int);
void    spacewarp(int);
void    stop(int);
int     stretch(struct point *);
void    surround(struct point *);
void    suspend(void);
void    win(struct point *);
void    winnings(int);

#ifdef LOGGING
void    logit(char *);
#endif

int     wantstop;

int
main(int argc, char *argv[])
{
        struct  sigaction sa;
        int     ch, i;

#ifdef LOGGING
        const char      *home;

        home = getenv("HOME");
        if (home == NULL || *home == '\0')
                err(1, "getenv");

        snprintf(logpath, sizeof(logpath), "%s/%s", home, ".snake.log");
        logfile = fopen(logpath, "a");
#endif

        while ((ch = getopt(argc, argv, "hl:stw:")) != -1)
                switch ((char)ch) {
                case 'w':       /* width */
                        ccnt = strtonum(optarg, 1, INT_MAX, NULL);
                        break;
                case 'l':       /* length */
                        lcnt = strtonum(optarg, 1, INT_MAX, NULL);
                        break;
                case 's': /* score */
                        if (readscores(0))
                                snscore(0);
                        else
                                printf("no scores so far\n");
                        return 0;
                        break;
                case 't': /* slow terminal */
                        fast = 0;
                        break;
                case 'h':
                default:
                        fprintf(stderr, "usage: %s [-st] [-l length] "
                            "[-w width]\n", getprogname());
                        return 1;
                }

        readscores(1);
        penalty = loot = 0;
        initscr();

        if (pledge("stdio tty", NULL) == -1)
                err(1, "pledge");

#ifdef KEY_LEFT
        keypad(stdscr, TRUE);
#endif
        nonl();
        cbreak();
        noecho();

        if (!lcnt || lcnt > LINES - 2)
                lcnt = LINES - 2;
        if (!ccnt || ccnt > COLS - 3)
                ccnt = COLS - 3;

        i = lcnt < ccnt ? lcnt : ccnt;
        if (i < 4) {
                endwin();
                errx(1, "screen too small for a fair game.");
        }
        /*
         * chunk is the amount of money the user gets for each $.
         * The formula below tries to be fair for various screen sizes.
         * We only pay attention to the smaller of the 2 edges, since
         * that seems to be the bottleneck.
         * This formula is a hyperbola which includes the following points:
         *      (24, $25)       (original scoring algorithm)
         *      (12, $40)       (experimentally derived by the "feel")
         *      (48, $15)       (a guess)
         * This will give a 4x4 screen $99/shot.  We don't allow anything
         * smaller than 4x4 because there is a 3x3 game where you can win
         * an infinite amount of money.
         */
        if (i < 12)
                i = 12; /* otherwise it isn't fair */
        /*
         * Compensate for border.  This really changes the game since
         * the screen is two squares smaller but we want the default
         * to be $25, and the high scores on small screens were a bit
         * much anyway.
         */
        i += 2;
        chunk = (675.0 / (i + 6)) + 2.5;        /* min screen edge */

        memset(&sa, 0, sizeof sa);
        sigemptyset(&sa.sa_mask);
        sa.sa_handler = stop;
        sigaction(SIGINT, &sa, NULL);

        snrand(&finish);
        snrand(&you);
        snrand(&money);
        snrand(&snake[0]);

        for (i = 1; i < 6; i++)
                chase(&snake[i], &snake[i - 1]);
        setup();
        mainloop();
        return 0;
}

/* Main command loop */
void
mainloop(void)
{
        int     k;
        int     c, lastc = 0;
        int repeat = 1;

        for (;;) {
                if (wantstop) {
                        endwin();
                        length(moves);
                        exit(0);
                }

                /* Highlight you, not left & above */
                move(you.line + 1, you.col + 1);
                refresh();
                if (((c = getch()) <= '9') && (c >= '0')) {
                        repeat = c - '0';
                        while (((c = getch()) <= '9') && (c >= '0'))
                                repeat = 10 * repeat + (c - '0');
                } else {
                        if (c != '.')
                                repeat = 1;
                }
                if (c == '.')
                        c = lastc;
                if (!fast)
                        flushinp();
                lastc = c;

                switch (c) {
                case CTRL('z'):
                        suspend();
                        continue;
                case '\044':
                case 'x':
                case 0177:      /* del or end of file */
                case ERR:
                        endwin();
                        length(moves);
#ifdef LOGGING
                        logit("quit");
#endif
                        exit(0);
                case CTRL('l'):
                        setup();
                        winnings(cashvalue);
                        continue;
                case 'p':
                case 'd':
                        snap();
                        continue;
                case 'w':
                        spacewarp(0);
                        continue;
                case 'A':
                        repeat = you.col;
                        c = 'h';
                        break;
                case 'H':
                case 'S':
                        repeat = you.col - money.col;
                        c = 'h';
                        break;
                case 'T':
                        repeat = you.line;
                        c = 'k';
                        break;
                case 'K':
                case 'E':
                        repeat = you.line - money.line;
                        c = 'k';
                        break;
                case 'P':
                        repeat = ccnt - 1 - you.col;
                        c = 'l';
                        break;
                case 'L':
                case 'F':
                        repeat = money.col - you.col;
                        c = 'l';
                        break;
                case 'B':
                        repeat = lcnt - 1 - you.line;
                        c = 'j';
                        break;
                case 'J':
                case 'C':
                        repeat = money.line - you.line;
                        c = 'j';
                        break;
                }
                for (k = 1; k <= repeat; k++) {
                        moves++;
                        switch (c) {
                        case 's':
                        case 'h':
#ifdef KEY_LEFT
                        case KEY_LEFT:
#endif
                        case '\b':
                                if (you.col > 0) {
                                        if ((fast) || (k == 1))
                                                pchar(&you, ' ');
                                        you.col--;
                                        if ((fast) || (k == repeat) ||
                                            (you.col == 0))
                                                pchar(&you, ME);
                                }
                                break;
                        case 'f':
                        case 'l':
#ifdef KEY_RIGHT
                        case KEY_RIGHT:
#endif
                        case ' ':
                                if (you.col < ccnt - 1) {
                                        if ((fast) || (k == 1))
                                                pchar(&you, ' ');
                                        you.col++;
                                        if ((fast) || (k == repeat) ||
                                            (you.col == ccnt - 1))
                                                pchar(&you, ME);
                                }
                                break;
                        case CTRL('p'):
                        case 'e':
                        case 'k':
#ifdef KEY_UP
                        case KEY_UP:
#endif
                        case 'i':
                                if (you.line > 0) {
                                        if ((fast) || (k == 1))
                                                pchar(&you, ' ');
                                        you.line--;
                                        if ((fast) || (k == repeat) ||
                                            (you.line == 0))
                                                pchar(&you, ME);
                                }
                                break;
                        case CTRL('n'):
                        case 'c':
                        case 'j':
#ifdef KEY_DOWN
                        case KEY_DOWN:
#endif
                        case '\n':
                        case '\r':
                        case 'm':
                                if (you.line + 1 < lcnt) {
                                        if ((fast) || (k == 1))
                                                pchar(&you, ' ');
                                        you.line++;
                                        if ((fast) || (k == repeat) ||
                                            (you.line == lcnt - 1))
                                                pchar(&you, ME);
                                }
                                break;
                        }

                        if (same(&you, &money)) {
                                loot += 25;
                                if (k < repeat)
                                        pchar(&you, ' ');
                                do {
                                        snrand(&money);
                                } while ((money.col == finish.col &&
                                    money.line == finish.line) ||
                                    (money.col < 5 && money.line == 0) ||
                                    (money.col == you.col &&
                                    money.line == you.line));
                                pchar(&money, TREASURE);
                                winnings(cashvalue);
/*                              continue;                Previously, snake missed a turn! */
                        }
                        if (same(&you, &finish)) {
                                win(&finish);
                                flushinp();
                                endwin();
                                printf("You have won with $%d.\n", cashvalue);
                                fflush(stdout);
#ifdef LOGGING
                                logit("won");
#endif
                                length(moves);
                                post(cashvalue, 1);
                                close(rawscores);
                                exit(0);
                        }
                        if (pushsnake())
                                break;
                }
        }
}

/* set up the board */
void
setup(void)
{
        int     i;

        erase();
        pchar(&you, ME);
        pchar(&finish, GOAL);
        pchar(&money, TREASURE);
        for (i = 1; i < 6; i++) {
                pchar(&snake[i], SNAKETAIL);
        }
        pchar(&snake[0], SNAKEHEAD);
        drawbox();
        refresh();
}

void
drawbox(void)
{
        int i;

        for (i = 1; i <= ccnt; i++) {
                mvaddch(0, i, '-');
                mvaddch(lcnt + 1, i, '-');
        }
        for (i = 0; i <= lcnt + 1; i++) {
                mvaddch(i, 0, '|');
                mvaddch(i, ccnt + 1, '|');
        }
}

void
snrand(struct point *sp)
{
        struct point p;
        int i;

        for (;;) {
                p.col = arc4random_uniform(ccnt);
                p.line = arc4random_uniform(lcnt);

                /* make sure it's not on top of something else */
                if (p.line == 0 && p.col < 5)
                        continue;
                if (same(&p, &you))
                        continue;
                if (same(&p, &money))
                        continue;
                if (same(&p, &finish))
                        continue;
                for (i = 0; i < 6; i++)
                        if (same(&p, &snake[i]))
                                break;
                if (i < 6)
                        continue;
                break;
        }
        *sp = p;
}

int
post(int iscore, int flag)
{
        struct  highscore tmp;
        int     rank = nscores;
        short   oldbest = 0;

        /* I want to printf() the scores for terms that clear on endwin(),
         * but this routine also gets called with flag == 0 to see if
         * the snake should wink.  If (flag) then we're at game end and
         * can printf.
         */
        if (flag == 0) {
                if (nscores > 0)
                        return (iscore > scores[nscores - 1].score);
                else
                        return (iscore > 0);
        }

        if (nscores > 0) {
                oldbest = scores[0].score;
                scores[nscores].score = iscore;
                if (nscores < TOPN)
                        nscores++;
        } else {
                nscores = 1;
                scores[0].score = iscore;
                oldbest = 0;
        }

        /* Insert this joker's current score */
        while (rank-- > 0 && iscore > scores[rank].score) {
                memcpy(&tmp, &scores[rank], sizeof(struct highscore));
                memcpy(&scores[rank], &scores[rank + 1],
                    sizeof(struct highscore));
                memcpy(&scores[rank + 1], &tmp, sizeof(struct highscore));
        }

        if (rank++ < 0)
                printf("\nYou bettered your previous best of $%d\n", oldbest);
        else if (rank < nscores)
                printf("\nYour score of $%d is ranked %d of all times!\n",
                    iscore, rank + 1);

        if (fseek(sf, 0L, SEEK_SET) == -1)
                err(1, "fseek");
        if (fwrite(scores, sizeof(scores[0]), nscores, sf) < (u_int)nscores)
                err(1, "fwrite");
        if (fclose(sf))
                err(1, "fclose");

        /* See if we have a new champ */
        snscore(TOPN);
        return(1);
}

const int       mx[8] = { 0, 1, 1, 1, 0,-1,-1,-1};
const int       my[8] = {-1,-1, 0, 1, 1, 1, 0,-1};
const float     absv[8] = {1, 1.4, 1, 1.4, 1, 1.4, 1, 1.4};
int     oldw = 0;

void
chase(struct point *np, struct point *sp)
{
        /* this algorithm has bugs; otherwise the snake would get too good */
        struct point d;
        int     w, i, wt[8];
        double  v1, v2, vp, max;

        d.col = you.col-sp->col;
        d.line = you.line-sp->line;
        v1 = sqrt((double)(d.col * d.col + d.line * d.line) );
        w  = 0;
        max = 0;
        for (i = 0; i < 8; i++) {
                vp = d.col * mx[i] + d.line * my[i];
                v2 = absv[i];
                if (v1 > 0)
                        vp = ((double)vp) / (v1 * v2);
                else
                        vp = 1.0;
                if (vp > max) {
                        max = vp;
                        w = i;
                }
        }
        for (i = 0; i < 8; i++) {
                d.col = sp->col + mx[i];
                d.line = sp->line + my[i];
                wt[i] = 0;
                if (d.col < 0 || d.col >= ccnt || d.line < 0 || d.line >= lcnt)
                        continue;
                /*
                 * Change to allow snake to eat you if you're on the money;
                 * otherwise, you can just crouch there until the snake goes
                 * away.  Not positive it's right.
                 *
                 * if (d.line == 0 && d.col < 5) continue;
                 */
                if (same(&d, &money) || same(&d,&finish))
                        continue;
                wt[i] = (i == w ? loot/10 : 1);
                if (i == oldw)
                        wt[i] += loot/20;
        }
        for (w = i = 0; i < 8; i++)
                w += wt[i];
        vp = arc4random_uniform(w);
        for (i = 0; i < 8; i++)
                if (vp < wt[i])
                        break;
                else
                        vp -= wt[i];
        if (i == 8) {
                printw("failure\n");
                i = 0;
                while (wt[i] == 0)
                        i++;
        }
        oldw = w = i;
        np->col = sp->col + mx[w];
        np->line = sp->line + my[w];
}

void
spacewarp(int w)
{
        struct point p;
        int     j;
        const char  *str;

        snrand(&you);
        p.col = COLS / 2 - 8;
        p.line = LINES / 2 - 1;
        if (p.col < 0)
                p.col = 0;
        if (p.line < 0)
                p.line = 0;
        if (w) {
                str = "BONUS!!!";
                loot = loot - penalty;
                penalty = 0;
        } else {
                str = "SPACE WARP!!!";
                penalty += loot / PENALTY;
        }
        for (j = 0; j < 3; j++) {
                erase();
                refresh();
                delay(5);
                mvaddstr(p.line + 1, p.col + 1, str);
                mvaddstr(0, 0, "");
                refresh();
                delay(10);
        }
        setup();
        winnings(cashvalue);
}

void
snap(void)
{

        if (!stretch(&money))
                if (!stretch(&finish)) {
                        pchar(&you, '?');
                        refresh();
                        delay(10);
                        pchar(&you, ME);
                }
        refresh();
}

int
stretch(struct point *ps)
{
        struct point p;

        p.col = you.col;
        p.line = you.line;
        if ((abs(ps->col - you.col) < (ccnt / 12)) && (you.line != ps->line)) {
                if (you.line < ps->line) {
                        for (p.line = you.line + 1; p.line <= ps->line; p.line++)
                                pchar(&p, 'v');
                        refresh();
                        delay(10);
                        for (; p.line > you.line; p.line--)
                                chk(&p);
                } else {
                        for (p.line = you.line - 1; p.line >= ps->line; p.line--)
                                pchar(&p, '^');
                        refresh();
                        delay(10);
                        for (; p.line < you.line; p.line++)
                                chk(&p);
                }
                return(1);
        } else if ((abs(ps->line - you.line) < (lcnt / 7)) && (you.col != ps->col)) {
                p.line = you.line;
                if (you.col < ps->col) {
                        for (p.col = you.col + 1; p.col <= ps->col; p.col++)
                                pchar(&p, '>');
                        refresh();
                        delay(10);
                        for (; p.col > you.col; p.col--)
                                chk(&p);
                } else {
                        for (p.col = you.col - 1; p.col >= ps->col; p.col--)
                                pchar(&p, '<');
                        refresh();
                        delay(10);
                        for (; p.col < you.col; p.col++)
                                chk(&p);
                }
                return(1);
        }
        return(0);
}

void
surround(struct point *ps)
{
        int     j;

        if (ps->col == 0)
                ps->col++;
        if (ps->line == 0)
                ps->line++;
        if (ps->line == LINES - 1)
                ps->line--;
        if (ps->col == COLS - 1)
                ps->col--;
        mvaddstr(ps->line, ps->col, "/*\\");
        mvaddstr(ps->line + 1, ps->col, "* *");
        mvaddstr(ps->line + 2, ps->col, "\\*/");
        for (j = 0; j < 20; j++) {
                pchar(ps, '@');
                refresh();
                delay(1);
                pchar(ps, ' ');
                refresh();
                delay(1);
        }
        if (post(cashvalue, 0)) {
                mvaddstr(ps->line, ps->col, "   ");
                mvaddstr(ps->line + 1, ps->col, "o.o");
                mvaddstr(ps->line + 2, ps->col, "\\_/");
                refresh();
                delay(6);
                mvaddstr(ps->line, ps->col, "   ");
                mvaddstr(ps->line + 1, ps->col, "o.-");
                mvaddstr(ps->line + 2, ps->col, "\\_/");
                refresh();
                delay(6);
        }
        mvaddstr(ps->line, ps->col, "   ");
        mvaddstr(ps->line + 1, ps->col, "o.o");
        mvaddstr(ps->line + 2, ps->col, "\\_/");
        refresh();
        delay(6);
}

void
win(struct point *ps)
{
        struct point x;
        int     j, k;
        int     boxsize;        /* actually diameter of box, not radius */

        boxsize = (fast ? 10 : 4);
        x.col = ps->col;
        x.line = ps->line;
        for (j = 1; j < boxsize; j++) {
                for (k = 0; k < j; k++) {
                        pchar(&x, '#');
                        x.line--;
                }
                for (k = 0; k < j; k++) {
                        pchar(&x, '#');
                        x.col++;
                }
                j++;
                for (k = 0; k < j; k++) {
                        pchar(&x, '#');
                        x.line++;
                }
                for (k = 0; k < j; k++) {
                        pchar(&x, '#');
                        x.col--;
                }
                refresh();
                delay(1);
        }
}

int
pushsnake(void)
{
        int     i, bonus;
        int     issame = 0;
        struct point tmp;

        for (i = 4; i >= 0; i--)
                if (same(&snake[i], &snake[5]))
                        issame++;
        if (!issame) {
                char sp = ' ';
                if (same(&money, &snake[5]))
                        sp = TREASURE;
                pchar(&snake[5], sp);
        }
        /* Need the following to catch you if you step on the snake's tail */
        tmp.col = snake[5].col;
        tmp.line = snake[5].line;
        for (i = 4; i >= 0; i--)
                snake[i + 1] = snake[i];
        chase(&snake[0], &snake[1]);
        pchar(&snake[1], SNAKETAIL);
        pchar(&snake[0], SNAKEHEAD);
        for (i = 0; i < 6; i++) {
                if ((same(&snake[i], &you)) || (same(&tmp, &you))) {
                        surround(&you);
                        i = (cashvalue) % 10;
                        bonus = arc4random_uniform(10);
                        refresh();
                        delay(30);
                        if (bonus == i) {
                                spacewarp(1);
#ifdef LOGGING
                                logit("bonus");
#endif
                                flushinp();
                                return(1);
                        }
                        flushinp();
                        endwin();
                        if (loot >= penalty) {
                                printf("\nYou and your $%d have been eaten\n", cashvalue);
                        } else {
                                printf("\nThe snake ate you.  You owe $%d.\n", -cashvalue);
                        }
#ifdef LOGGING
                        logit("eaten");
#endif
                        length(moves);
                        snscore(TOPN);
                        close(rawscores);
                        exit(0);
                }
        }
        return(0);
}

int
chk(struct point *sp)
{
        int     j;

        if (same(sp, &money)) {
                pchar(sp, TREASURE);
                return(2);
        }
        if (same(sp, &finish)) {
                pchar(sp, GOAL);
                return(3);
        }
        if (same(sp, &snake[0])) {
                pchar(sp, SNAKEHEAD);
                return(4);
        }
        for (j = 1; j < 6; j++) {
                if (same(sp, &snake[j])) {
                        pchar(sp, SNAKETAIL);
                        return(4);
                }
        }
        if ((sp->col < 4) && (sp->line == 0)) {
                winnings(cashvalue);
                if ((you.line == 0) && (you.col < 4))
                        pchar(&you, ME);
                return(5);
        }
        if (same(sp, &you)) {
                pchar(sp, ME);
                return(1);
        }
        pchar(sp, ' ');
        return(0);
}

void
winnings(int won)
{
        if (won > 0)
                mvprintw(1, 1, "$%d  ", won);
}

void
stop(int dummy)
{
        wantstop = 1;
}

void
suspend(void)
{
        endwin();
        kill(getpid(), SIGTSTP);
        refresh();
        winnings(cashvalue);
}

void
length(int num)
{
        printf("You made %d moves.\n", num);
}

void
snscore(int topn)
{
        int i;

        if (nscores == 0)
                return;

        printf("%sSnake scores to date:\n", topn > 0 ? "Top " : "");
        for (i = 0; i < nscores; i++)
                printf("%2d.\t$%d\t%s\n", i+1, scores[i].score, scores[i].name);
}

#ifdef LOGGING
void
logit(char *msg)
{
        time_t t;

        if (logfile != NULL) {
                time(&t);
                fprintf(logfile, "%s $%d %dx%d %s %s",
                    getlogin(), cashvalue, lcnt, ccnt, msg, ctime(&t));
                fflush(logfile);
        }
}
#endif

int
readscores(int create)
{
        const char      *home;
        const char      *name;
        const char      *modstr;
        int              modint;
        int              ret;

        if (create == 0) {
                modint = O_RDONLY;
                modstr = "r";
        } else {
                modint = O_RDWR | O_CREAT;
                modstr = "r+";
        }

        home = getenv("HOME");
        if (home == NULL || *home == '\0')
                err(1, "getenv");

        ret = snprintf(scorepath, sizeof(scorepath), "%s/%s", home,
            ".snake.scores");
        if (ret < 0 || ret >= PATH_MAX)
                errc(1, ENAMETOOLONG, "%s/%s", home, ".snake.scores");

        rawscores = open(scorepath, modint, 0666);
        if (rawscores == -1) {
                if (create == 0)
                        return 0;
                err(1, "cannot open %s", scorepath);
        }
        if ((sf = fdopen(rawscores, modstr)) == NULL)
                err(1, "cannot fdopen %s", scorepath);
        nscores = fread(scores, sizeof(scores[0]), TOPN, sf);
        if (ferror(sf))
                err(1, "error reading %s", scorepath);

        name = getenv("LOGNAME");
        if (name == NULL || *name == '\0')
                name = getenv("USER");
        if (name == NULL || *name == '\0')
                name = getlogin();
        if (name == NULL || *name == '\0')
                name = "  ???";

        if (nscores > TOPN)
                nscores = TOPN;
        strlcpy(scores[nscores].name, name, sizeof(scores[nscores].name));
        scores[nscores].score = 0;

        return 1;
}