/*	$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);
}
