/*      $NetBSD: tetris.c,v 1.34 2023/07/01 10:51:35 nia Exp $  */

/*-
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek and Darren F. Provine.
 *
 * 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.
 *
 *      @(#)tetris.c    8.1 (Berkeley) 5/31/93
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1992, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

/*
 * Tetris (or however it is spelled).
 */

#include <sys/time.h>

#include <err.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "input.h"
#include "scores.h"
#include "screen.h"
#include "tetris.h"

cell    board[B_SIZE];          /* 1 => occupied, 0 => empty */

int     Rows, Cols;             /* current screen size */
int     Offset;                 /* used to center board & shapes */

static const struct shape *curshape;
const struct shape *nextshape;

long    fallrate;               /* less than 1 million; smaller => faster */

int     score;                  /* the obvious thing */
gid_t   gid, egid;

char    key_msg[100];
int     showpreview;
int     nocolor;

static void elide(void);
static void setup_board(void);
static void onintr(int) __dead;
static void usage(void) __dead;

/*
 * Set up the initial board.  The bottom display row is completely set,
 * along with another (hidden) row underneath that.  Also, the left and
 * right edges are set.
 */
static void
setup_board(void)
{
        int i;
        cell *p;

        p = board;
        for (i = B_SIZE; i; i--)
                *p++ = (i <= (2 * B_COLS) || (i % B_COLS) < 2) ? 7 : 0;
}

/*
 * Elide any full active rows.
 */
static void
elide(void)
{
        int i, j, base;
        cell *p;

        for (i = A_FIRST; i < A_LAST; i++) {
                base = i * B_COLS + 1;
                p = &board[base];
                for (j = B_COLS - 2; *p++ != 0;) {
                        if (--j <= 0) {
                                /* this row is to be elided */
                                memset(&board[base], 0, B_COLS - 2);
                                scr_update();
                                tsleep();
                                while (--base != 0)
                                        board[base + B_COLS] = board[base];
                                /* don't forget to clear 0th row */
                                memset(&board[1], 0, B_COLS - 2);
                                scr_update();
                                tsleep();
                                break;
                        }
                }
        }
}

int
main(int argc, char *argv[])
{
        int pos, c;
        const char *keys;
        int level = 2;
#define NUMKEYS 7
        char key_write[NUMKEYS][10];
        char *nocolor_env;
        int ch, i, j;
        int fd;

        gid = getgid();
        egid = getegid();
        setegid(gid);

        fd = open("/dev/null", O_RDONLY);
        if (fd < 3)
                exit(1);
        close(fd);

        keys = "jkl pqn";

        while ((ch = getopt(argc, argv, "bk:l:ps")) != -1)
                switch(ch) {
                case 'b':
                        nocolor = 1;
                        break;
                case 'k':
                        if (strlen(keys = optarg) != NUMKEYS)
                                usage();
                        break;
                case 'l':
                        level = atoi(optarg);
                        if (level < MINLEVEL || level > MAXLEVEL) {
                                errx(1, "level must be from %d to %d",
                                     MINLEVEL, MAXLEVEL);
                        }
                        break;
                case 'p':
                        showpreview = 1;
                        break;
                case 's':
                        showscores(0);
                        exit(0);
                case '?':
                default:
                        usage();
                }

        argc -= optind;
        argv += optind;

        if (argc)
                usage();

        nocolor_env = getenv("NO_COLOR");

        if (nocolor_env != NULL && nocolor_env[0] != '\0')
                nocolor = 1;

        fallrate = 1000000 / level;

        for (i = 0; i <= (NUMKEYS-1); i++) {
                for (j = i+1; j <= (NUMKEYS-1); j++) {
                        if (keys[i] == keys[j]) {
                                errx(1, "duplicate command keys specified.");
                        }
                }
                if (keys[i] == ' ')
                        strcpy(key_write[i], "<space>");
                else {
                        key_write[i][0] = keys[i];
                        key_write[i][1] = '\0';
                }
        }

        snprintf(key_msg, sizeof(key_msg),
"%s - left  %s - rotate  %s - right  %s - drop  %s - pause  %s - quit  %s - down",
                key_write[0], key_write[1], key_write[2], key_write[3],
                key_write[4], key_write[5], key_write[6]);

        (void)signal(SIGINT, onintr);
        scr_init();
        setup_board();

        scr_set();

        pos = A_FIRST*B_COLS + (B_COLS/2)-1;
        nextshape = randshape();
        curshape = randshape();

        scr_msg(key_msg, 1);

        for (;;) {
                place(curshape, pos, 1);
                scr_update();
                place(curshape, pos, 0);
                c = tgetchar();
                if (c < 0) {
                        /*
                         * Timeout.  Move down if possible.
                         */
                        if (fits_in(curshape, pos + B_COLS)) {
                                pos += B_COLS;
                                continue;
                        }

                        /*
                         * Put up the current shape `permanently',
                         * bump score, and elide any full rows.
                         */
                        place(curshape, pos, 1);
                        score++;
                        elide();

                        /*
                         * Choose a new shape.  If it does not fit,
                         * the game is over.
                         */
                        curshape = nextshape;
                        nextshape = randshape();
                        pos = A_FIRST*B_COLS + (B_COLS/2)-1;
                        if (!fits_in(curshape, pos))
                                break;
                        continue;
                }

                /*
                 * Handle command keys.
                 */
                if (c == keys[5]) {
                        /* quit */
                        break;
                }
                if (c == keys[4]) {
                        static char msg[] =
                            "paused - press RETURN to continue";

                        place(curshape, pos, 1);
                        do {
                                scr_update();
                                scr_msg(key_msg, 0);
                                scr_msg(msg, 1);
                                (void) fflush(stdout);
                        } while (rwait(NULL) == -1);
                        scr_msg(msg, 0);
                        scr_msg(key_msg, 1);
                        place(curshape, pos, 0);
                        continue;
                }
                if (c == keys[0]) {
                        /* move left */
                        if (fits_in(curshape, pos - 1))
                                pos--;
                        continue;
                }
                if (c == keys[1]) {
                        /* turn */
                        const struct shape *new = &shapes[curshape->rot];

                        if (fits_in(new, pos))
                                curshape = new;
                        continue;
                }
                if (c == keys[2]) {
                        /* move right */
                        if (fits_in(curshape, pos + 1))
                                pos++;
                        continue;
                }
                if (c == keys[3]) {
                        /* move to bottom */
                        while (fits_in(curshape, pos + B_COLS)) {
                                pos += B_COLS;
                                score++;
                        }
                        continue;
                }
                if (c == keys[6]) {
                        /* move down */
                        if (fits_in(curshape, pos + B_COLS)) {
                                pos += B_COLS;
                                score++;
                        }
                        continue;
                }
                if (c == '\f') {
                        scr_clear();
                        scr_msg(key_msg, 1);
                }
        }

        scr_clear();
        scr_end();

        (void)printf("Your score:  %d point%s  x  level %d  =  %d\n",
            score, score == 1 ? "" : "s", level, score * level);
        savescore(level);

        printf("\nHit RETURN to see high scores, ^C to skip.\n");

        while ((i = getchar()) != '\n')
                if (i == EOF)
                        break;

        showscores(level);

        exit(0);
}

static void
onintr(int signo __unused)
{
        scr_clear();
        scr_end();
        exit(0);
}

static void
usage(void)
{
        (void)fprintf(stderr, "usage: %s [-bps] [-k keys] [-l level]\n",
            getprogname());
        exit(1);
}