/*	$OpenBSD: move.c,v 1.1 1999/03/13 02:08:09 pjanzen Exp $	*/
/*	$NetBSD: move.c,v 1.12 1996/05/19 20:22:09 pk 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 */

#ifndef lint
#if 0
static char sccsid[] = "@(#)move.c	8.1 (Berkeley) 7/19/93";
#else
static char rcsid[] = "$OpenBSD: move.c,v 1.1 1999/03/13 02:08:09 pjanzen Exp $";
#endif
#endif /* not lint */

/*************************************************************************
 *
 *	MOVE LIBRARY
 *
 *	This set of subroutines moves a cursor to a predefined
 *	location, independent of the terminal type.  If the
 *	terminal has an addressable cursor, it uses it.  If
 *	not, it optimizes for tabs (currently) even if you don't
 *      have them.
 *
 *	At all times the current address of the cursor must be maintained,
 *	and that is available as structure cursor.
 *
 *	The following calls are allowed:
 *		move(sp)	move to point sp.
 *		up()		move up one line.
 *		down()		move down one line.
 *		bs()		move left one space (except column 0).
 *		nd()		move right one space(no write).
 *		clear()		clear screen.
 *		home()		home.
 *		ll()		move to lower left corner of screen.
 *		cr()		carriage return (no line feed).
 *		pr()		just like standard printf, but keeps track
 *				of cursor position. (Uses pstring).
 *		apr()		same as printf, but first argument is &point.
 *				(Uses pstring).
 *		pstring(s)	output the string of printing characters.
 *				However, '\r' is interpreted to mean return
 *				to column of origination AND do linefeed.
 *				'\n' causes <cr><lf>.
 *		putpad(str)	calls tputs to output character with proper
 *					padding.
 *		outch()		the output routine for a character used by
 *					tputs. It just calls putchar.
 *		pch(ch)		output character to screen and update
 *					cursor address (must be a standard
 *					printing character). WILL SCROLL.
 *		pchar(ps,ch)	prints one character if it is on the
 *					screen at the specified location;
 *					otherwise, dumps it.(no wrap-around).
 *
 *		getcap()	initializes strings for later calls.
 *		cap(string)	outputs the string designated in the termcap
 *					data base. (Should not move the cursor.)
 *
 *		cook()		returns the terminal to initial state.
 *
 *		point(&p,x,y)	return point set to x,y.
 *
 *		delay(t)	causes an approximately constant delay
 *					independent of baudrate.
 *					Duration is ~ t/20 seconds.
 *
 ******************************************************************************/

#ifdef __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#include <err.h>
#include <stdlib.h>
#include <term.h>
#include <unistd.h>
#include "snake.h"

int	CMlength;
int	NDlength;
int	BSlength;
int	delaystr[10];
speed_t	ospeed;

static char str[80];

void
move(sp)
	struct point *sp;
{
	int	distance;
	int	tabcol, ct;
	struct point z;

	if (sp->line < 0 || sp->col < 0 || sp->col > COLUMNS) {
		pr("move to [%d,%d]?", sp->line, sp->col);
		return;
	}
	if (sp->line >= LINES) {
		move(point(&z, sp->col, LINES - 1));
		while (sp->line-- >= LINES)
			putchar('\n');
		return;
	}

	if (CM != 0) {
		char *cmstr = tgoto(CM, sp->col, sp->line);

		CMlength = strlen(cmstr);
		if (cursor.line == sp->line) {
			distance = sp->col - cursor.col;
			if (distance == 0)
				return;	/* Already there! */
			if (distance > 0) {	/* Moving to the right */
				if (distance * NDlength < CMlength) {
					right(sp);
					return;
				}
				if (TA) {
					ct = sp->col & 7;
					tabcol = (cursor.col | 7) + 1;
					do {
						ct++;
						tabcol = (tabcol | 7) + 1;
					}
					while (tabcol < sp->col);
					if (ct<CMlength) {
						right(sp);
						return;
					}
				}
			} else {		/* Moving to the left */
				if (-distance * BSlength < CMlength) {
					gto(sp);
					return;
				}
			}
			if (sp->col < CMlength) {
				cr();
				right(sp);
				return;
			}
				/* No more optimizations on same row. */
		}
		distance = sp->col - cursor.col;
		distance = distance > 0 ?
			distance * NDlength : -distance * BSlength;
		if (distance < 0)
			pr("ERROR: distance is negative: %d", distance);
		distance += abs(sp->line - cursor.line);
		if (distance >= CMlength) {
			putpad(cmstr);
			cursor.line = sp->line;
			cursor.col = sp->col;
			return;
		}
	}
	/*
	 * If we get here we have a terminal that can't cursor
	 * address but has local motions or one which can cursor
	 * address but can get there quicker with local motions.
	 */
	 gto(sp);
}

void
gto(sp)
	struct point *sp;
{
	int distance, f, tfield;

	if (cursor.line > LINES || cursor.line <0 ||
		cursor.col <0 || cursor.col > COLUMNS)
		pr("ERROR: cursor is at %d,%d\n", cursor.line, cursor.col);
	if (sp->line > LINES || sp->line < 0 || sp->col < 0 || sp->col > COLUMNS)
		pr("ERROR: target is %d,%d\n", sp->line, sp->col);
	tfield = (sp->col) >> 3;
	if (sp->line == cursor.line) {
		if (sp->col > cursor.col)
			right(sp);
		else {
			distance = (cursor.col - sp->col) * BSlength;
			if (((TA) && (distance > tfield + ((sp->col) & 7) * NDlength)) || 
				(((cursor.col)*NDlength) < distance)) {
				cr();
				right(sp);
			} else {
				while(cursor.col > sp->col)
					bs();
			}
		}
		return;
	}
				/*must change row */
	if (cursor.col - sp->col > (cursor.col >> 3)) {
		if (cursor.col == 0)
			f = 0;
		else
			f = -1;
	}
	else f = cursor.col >> 3;
	if (((sp->line << 1) + 1 < cursor.line - f) && (HO != 0)) {
			/*
			 * home quicker than rlf:
			 * (sp->line + f > cursor.line - sp->line)
			 */
		putpad(HO);
		cursor.col = cursor.line = 0;
		gto(sp);
		return;
	}
	if (((sp->line << 1) > cursor.line + LINES + 1 + f) && (LL != 0)) {
		/* home,rlf quicker than lf
		 * (LINES+1 - sp->line + f < sp->line - cursor.line) 
		 */
		if (cursor.line > f + 1) {
		/* is home faster than wraparound lf?
		 * (cursor.line + 20 - sp->line > 21 - sp->line + f)
		 */
			ll();
			gto(sp);
			return;
		}
	}
	if ((LL != 0) && (sp->line > cursor.line + (LINES >> 1) - 1))
		cursor.line += LINES;
	while(sp->line > cursor.line)
		down();
	while(sp->line < cursor.line)
		up();
	gto(sp);		/*can recurse since cursor.line = sp->line */
}

void
right(sp)
	struct point *sp;
{
	int	field, tfield;
	int	tabcol, strlength;

	if (sp->col < cursor.col)
		pr("ERROR:right() can't move left\n");
	if (TA) {		/* If No Tabs: can't send tabs because ttydrive
			 * loses count with control characters.
			 */
		field = cursor.col >> 3;
/*
 *	This code is useful for a terminal which wraps around on backspaces.
 *	(Mine does.)  Unfortunately, this is not specified in termcap, and
 *	most terminals don't work that way.  (Of course, most terminals
 *	have addressible cursors, too).
 */
		if (BW && (CM == 0) &&
		    ((sp->col << 1) - field > (COLUMNS - 8) << 1 )) {
	 		if (cursor.line == 0) 
	 			outch('\n');
	 		outch('\r');
	 		cursor.col = COLUMNS + 1;
	 		while (cursor.col > sp->col)
				bs();
	 		if (cursor.line != 0)
				outch('\n');
	 		return;
	 	}
		tfield = sp->col >> 3;

		while (field < tfield) {
			putpad(TA);
			cursor.col = ++field << 3;
		}
		tabcol = (cursor.col | 7) + 1;
		strlength = (tabcol - sp->col) * BSlength + 1;
		/* length of sequence to overshoot */
		if (((sp->col - cursor.col) * NDlength > strlength) &&
		    (tabcol < COLUMNS)
		   ){
			/* Tab past and backup */
			putpad(TA);
			cursor.col = (cursor.col | 7) + 1;
			while(cursor.col > sp->col)
				bs();
		}
	}
	while (sp->col > cursor.col) {
		nd();
	}
}

void
cr()
{
	outch('\r');
	cursor.col = 0;
}

void
clear()
{
	int i;

	if (CL){
		putpad(CL);
		cursor.col = cursor.line = 0;
	} else {
		for(i=0; i<LINES; i++) {
			putchar('\n');
		}
		cursor.line = LINES - 1;
		home();
	}
}

void
home()
{
	struct point z;

	if (HO != 0) {
		putpad(HO);
		cursor.col = cursor.line = 0;
		return;
	}
	z.col = z.line = 0;
	move(&z);
}

void
ll()
{
	int l;
	struct point z;

	l = lcnt + 2;
	if (LL != NULL && LINES == l) {
		putpad(LL);
		cursor.line = LINES - 1;
		cursor.col = 0;
		return;
	}
	z.col = 0;
	z.line = l - 1;
	move(&z);
}

void
up()
{
	putpad(UP);
	cursor.line--;
}

void
down()
{
	putpad(DO);
	cursor.line++;
	if (cursor.line >= LINES)
		cursor.line = LINES - 1;
}

void
bs()
{
	if (cursor.col > 0) {
		putpad(BS);
		cursor.col--;
	}
}

void
nd()
{
	putpad(ND);
	cursor.col++;
	if (cursor.col == COLUMNS + 1) {
		cursor.line++;
		cursor.col = 0;
		if (cursor.line >= LINES)
			cursor.line = LINES - 1;
	}
}

void
pch(c)
	int c;
{
	outch(c);
	if(++cursor.col >= COLUMNS && AM) {
		cursor.col = 0;
		++cursor.line;
	}
}

void
#ifdef __STDC__
apr(struct point *ps, const char *fmt, ...)
#else
apr(ps, fmt, va_alist)
	struct point *ps;
	char *fmt;
	va_dcl
#endif
{
	struct point p;
	va_list ap;

	p.line = ps->line + 1;
	p.col = ps->col + 1;
	move(&p);
#ifdef __STDC__
	va_start(ap, fmt);
#else
	va_start(ap);
#endif
	(void)vsprintf(str, fmt, ap);
	va_end(ap);
	pstring(str);
}

void
#ifdef __STDC__
pr(const char *fmt, ...)
#else
pr(fmt, va_alist)
	char *fmt;
	va_dcl
#endif
{
	va_list ap;

#ifdef __STDC__
	va_start(ap, fmt);
#else
	va_start(ap);
#endif
	(void)vsprintf(str, fmt, ap);
	va_end(ap);
	pstring(str);
}

void
pstring(s)
	const char *s;
{
	struct point z;
	int stcol;

	stcol = cursor.col;
	while (s[0] != '\0') {
		switch (s[0]) {
		case '\n':
			move(point(&z, 0, cursor.line + 1));
			break;
		case '\r':
			move(point(&z, stcol, cursor.line + 1));
			break;
		case '\t':
			z.col = (((cursor.col + 8) >> 3) << 3);
			z.line = cursor.line;
			move(&z);
			break;
		case '\b':
			bs();
			break;
		case CTRL('g'):
			outch(CTRL('g'));
			break;
		default:
			if (s[0] < ' ')
				break;
			pch(s[0]);
		}
		s++;
	}
}

void
pchar(ps,ch)
	struct point *ps;
	char ch;
{
	struct point p;

	p.col = ps->col + 1;
	p.line = ps->line + 1;
	if ((p.col >= 0) && (p.line >= 0) &&
		(((p.line < LINES) && (p.col < COLUMNS)) ||
			((p.col == COLUMNS) && (p.line < LINES-1)))) {
		move(&p);
		pch(ch);
	}
}
			
int
outch(c)
	int c;
{
	putchar(c);
	return(0);
}

void
putpad(str)
	char *str;
{
	if (str)
		tputs(str, 1, outch);
}

void
delay(t)
	int t;
{
	useconds_t us;
	/* This can't depend on terminal timing in light of X */
	
	us = t * 50000;	/* From units of 1/20 s */
	usleep(us);
}

void
cook()
{
	delay(1);
	putpad(TE);
	putpad(KE);
	putpad(VE);
	fflush(stdout);
	tcsetattr(0, TCSADRAIN, &orig);
}

void
raw()
{
	tcsetattr(0, TCSADRAIN, &new);
	putpad(VI);
}

struct point *
point(ps, x, y)
	struct point *ps;
	int	x, y;
{
	ps->col  = x;
	ps->line = y;
	return(ps);
}

void
getcap()
{
	char *ap;
	char	*term;
	char	*xPC;
#ifdef TIOCGWINSZ
	struct winsize win;
#endif

	term = getenv("TERM");
	if (term == 0)
		errx(1, "No TERM in environment");
	switch (tgetent(tbuf, term)) {
	case -1:
		errx(2, "Cannot open termcap file");
	case 0:
		errx(3, "unknown terminal `%s'", term);
	}

	ap = tcapbuf;

#ifdef TIOCGWINSZ
	if (ioctl(0, TIOCGWINSZ, (char *) &win) < 0 ||
	    (LINES = win.ws_row) == 0 || (COLUMNS = win.ws_col) == 0) {
#endif
		LINES = tgetnum("li");
		COLUMNS = tgetnum("co");
#ifdef TIOCGWINSZ
	}
#endif
	if (!lcnt)
		lcnt = LINES - 2;
	if (!ccnt)
		ccnt = COLUMNS - 3;
	/* make sure user didn't specify a screen larger than he has */
	if (lcnt > LINES - 2)
		lcnt = LINES - 2;
	if (ccnt > COLUMNS - 3)
		ccnt = COLUMNS - 3;

	AM = tgetflag("am");
	BW = tgetflag("bw");

	ND = tgetstr("nd", &ap);
	UP = tgetstr("up", &ap);

	DO = tgetstr("do", &ap);
	if (DO == 0)
		DO = "\n";

	BS = tgetstr("le", &ap);
	if (BS == 0) {
		/* try using obsolete capabilities */
		BS = tgetstr("bc", &ap);
		if (BS == 0 && tgetflag("bs"))
			BS = "\b";
	}
	TA = tgetstr("ta", &ap);
	if (TA == 0 && tgetflag("pt"))
		TA = "\t";

	HO = tgetstr("ho", &ap);
	CL = tgetstr("cl", &ap);
	CM = tgetstr("cm", &ap);
	LL = tgetstr("ll", &ap);

	KL = tgetstr("kl", &ap);
	KR = tgetstr("kr", &ap);
	KU = tgetstr("ku", &ap);
	KD = tgetstr("kd", &ap);
	if (KL && KR && KU && KD)
		Klength = strlen(KL);
	else
		Klength = 0;
	/*	NOTE:   If KL, KR, KU, and KD are not
	 *		all the same length, some problems
	 *		may arise, since tests are made on
	 *		all of them together.
	 */

	TI = tgetstr("ti", &ap);
	TE = tgetstr("te", &ap);
	KS = tgetstr("ks", &ap);
	KE = tgetstr("ke", &ap);
	VE = tgetstr("ve", &ap);
	VI = tgetstr("vi", &ap);

	xPC = tgetstr("pc", &ap);
	if (xPC)
		PC = *xPC;

	if ((CM == 0) &&
		(HO == 0 || UP == 0 || BS == 0 || ND == 0))
		errx(5, "Terminal must have addressable cursor or home + 4 local motions");
	if (ND == 0)
		errx(5, "Terminal must have `nd' capability");
	NDlength = strlen(ND);
	if (BS == 0)
		errx(5, "Terminal must have `le' or `bs' or `bc' capability");
	BSlength = strlen(BS);
	if (tgetflag("os"))
		errx(5, "Terminal must not overstrike");
	if (LINES <= 0 || COLUMNS <= 0)
		errx(5, "Must know the screen size");

	tcgetattr(0, &orig);
	new = orig;
	new.c_lflag &= ~(ECHO | ICANON);
	new.c_oflag &= ~(ONLCR | OXTABS);
	signal(SIGINT, stop);
	ospeed = cfgetospeed(&orig);
	new.c_cc[VSUSP] = _POSIX_VDISABLE;
	new.c_cc[VDSUSP] = _POSIX_VDISABLE;
	raw();

	if (orig.c_oflag & OXTABS)
		TA=0;
	putpad(KS);
	putpad(TI);
	point(&cursor, 0, LINES - 1);
}