/*
 * Copyright 2001 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
/*	  All Rights Reserved  	*/

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*LINTLIBRARY*/

#ifndef lint
static char
sccsid[] = "@(#)refresh.c 1.8 89/08/24 SMI"; /* from UCB 5.1 85/06/07 */
#endif /* not lint */

/*
 * make the current screen look like "win" over the area coverd by
 * win.
 */

#include	"curses.ext"
#include	<term.h>
#include	<string.h>

#ifdef DEBUG
#define	DEBUGSTATIC
#else
#define	DEBUGSTATIC	static
#endif

DEBUGSTATIC short	ly, lx;
DEBUGSTATIC bool	curwin;
WINDOW	*_win = NULL;

/* forward declarations */
DEBUGSTATIC void domvcur(int, int, int, int);
DEBUGSTATIC int makech(WINDOW *, short);

int
wrefresh(WINDOW *win)
{
	short	wy;
	int	retval;

	/*
	 * make sure were in visual state
	 */
	if (_endwin) {
		(void) _puts(VS);
		(void) _puts(TI);
		_endwin = FALSE;
	}

	/*
	 * initialize loop parameters
	 */

	ly = curscr->_cury;
	lx = curscr->_curx;
	_win = win;
	curwin = (win == curscr);

	if (win->_clear || curscr->_clear || curwin) {
		if ((win->_flags & _FULLWIN) || curscr->_clear) {
			(void) _puts(CL);
			ly = 0;
			lx = 0;
			if (!curwin) {
				curscr->_clear = FALSE;
				curscr->_cury = 0;
				curscr->_curx = 0;
				(void) werase(curscr);
			}
			(void) touchwin(win);
		}
		win->_clear = FALSE;
	}
	if (!CA) {
		if (win->_curx != 0)
			(void) _putchar('\n');
		if (!curwin)
			(void) werase(curscr);
	}
#ifdef DEBUG
	fprintf(outf, "REFRESH(%0.2o): curwin = %d\n", win, curwin);
	fprintf(outf, "REFRESH:\n\tfirstch\tlastch\n");
#endif
	for (wy = 0; wy < win->_maxy; wy++) {
#ifdef DEBUG
		fprintf(outf, "%d\t%d\t%d\n", wy, win->_firstch[wy],
		    win->_lastch[wy]);
#endif
		if (win->_firstch[wy] != _NOCHANGE)
			if (makech(win, wy) == ERR)
				return (ERR);
			else {
				if (win->_firstch[wy] >= win->_ch_off)
					win->_firstch[wy] = win->_maxx +
							    win->_ch_off;
				if (win->_lastch[wy] < win->_maxx +
				    win->_ch_off)
					win->_lastch[wy] = win->_ch_off;
				if (win->_lastch[wy] < win->_firstch[wy])
					win->_firstch[wy] = _NOCHANGE;
			}
#ifdef DEBUG
		fprintf(outf, "\t%d\t%d\n", win->_firstch[wy],
		    win->_lastch[wy]);
#endif
	}

	if (win == curscr)
		domvcur(ly, lx, win->_cury, win->_curx);
	else {
		if (win->_leave) {
			curscr->_cury = ly;
			curscr->_curx = lx;
			ly -= win->_begy;
			lx -= win->_begx;
			if (ly >= 0 && ly < win->_maxy && lx >= 0 &&
			    lx < win->_maxx) {
				win->_cury = ly;
				win->_curx = lx;
			}
			else
				win->_cury = win->_curx = 0;
		} else {
			domvcur(ly, lx, win->_cury + win->_begy,
				win->_curx + win->_begx);
			curscr->_cury = win->_cury + win->_begy;
			curscr->_curx = win->_curx + win->_begx;
		}
	}
	retval = OK;

	_win = NULL;
	(void) fflush(stdout);
	return (retval);
}

/*
 * make a change on the screen
 */

DEBUGSTATIC int
makech(WINDOW *win, short wy)
{
	char	*nsp, *csp, *ce;
	short	wx, lch, y;
	intptr_t	nlsp, clsp;	/* last space in lines		*/

	wx = win->_firstch[wy] - win->_ch_off;
	if (wx >= win->_maxx)
		return (OK);
	else if (wx < 0)
		wx = 0;
	lch = win->_lastch[wy] - win->_ch_off;
	if (lch < 0)
		return (OK);
	else if (lch >= win->_maxx)
		lch = win->_maxx - 1;
	y = wy + win->_begy;

	if (curwin)
		csp = " ";
	else
		csp = &curscr->_y[wy + win->_begy][wx + win->_begx];

	nsp = &win->_y[wy][wx];
	if (CE && !curwin) {
		for (ce = &win->_y[wy][win->_maxx - 1]; *ce == ' '; ce--)
			if (ce <= win->_y[wy])
				break;
		nlsp = ce - win->_y[wy];
	}

	if (!curwin)
		ce = CE;
	else
		ce = NULL;

	while (wx <= lch) {
		if (*nsp != *csp) {
			domvcur(ly, lx, y, wx + win->_begx);
#ifdef DEBUG
			fprintf(outf, "MAKECH: 1: wx = %d, lx = %d\n", wx, lx);
#endif
			ly = y;
			lx = wx + win->_begx;
			while (wx <= lch && *nsp != *csp) {
				if (ce != NULL && wx >= nlsp && *nsp == ' ') {
					/*
					 * check for clear to end-of-line
					 */
					ce = &curscr->_y[ly][COLS - 1];
					while (*ce == ' ')
						if (ce-- <= csp)
							break;
					clsp = ce - curscr->_y[ly] - win->_begx;
#ifdef DEBUG
					fprintf(outf, "MAKECH: clsp = %d,"
					    " nlsp = %d\n", clsp, nlsp);
#endif
					if (clsp - nlsp >= strlen(CE) &&
					    clsp < win->_maxx) {
#ifdef DEBUG
						fprintf(outf, "MAKECH: using"
						    " CE\n");
#endif
						(void) _puts(CE);
						lx = wx + win->_begx;
						while (wx++ <= clsp)
							*csp++ = ' ';
						return (OK);
					}
					ce = NULL;
				}
				/*
				 * enter/exit standout mode as appropriate
				 */
				if (SO && (*nsp&_STANDOUT) !=
				    (curscr->_flags&_STANDOUT)) {
					if (*nsp & _STANDOUT) {
						(void) _puts(SO);
						curscr->_flags |= _STANDOUT;
					} else {
						(void) _puts(SE);
						curscr->_flags &= ~_STANDOUT;
					}
				}
				wx++;
				if (wx >= win->_maxx && wy == win->_maxy - 1)
					if (win->_scroll) {
					    if ((curscr->_flags&_STANDOUT) &&
						(win->_flags & _ENDLINE))
						    if (!MS) {
							(void) _puts(SE);
							curscr->_flags &=
							    ~_STANDOUT;
						    }
					    if (!curwin)
						(void) _putchar((*csp = *nsp) &
						    0177);
					    else
						(void) _putchar(*nsp & 0177);
					    if (win->_flags&_FULLWIN && !curwin)
						(void) scroll(curscr);
					    if (!curwin) {
						    ly = wy + win->_begy;
						    lx = wx + win->_begx;
					    } else {
						    ly = win->_begy+win->_cury;
						    lx = win->_begx+win->_curx;
					    }
					    return (OK);
					} else if (win->_flags&_SCROLLWIN) {
					    wx = wx - 1;
					    lx = wx;
					    return (ERR);
					}
				if (!curwin)
					(void) _putchar((*csp++ = *nsp) & 0177);
				else
					(void) _putchar(*nsp & 0177);
#ifdef FULLDEBUG
				fprintf(outf,
					"MAKECH:putchar(%c)\n", *nsp & 0177);
#endif
				if (UC && (*nsp & _STANDOUT)) {
					(void) _putchar('\b');
					(void) _puts(UC);
				}
				nsp++;
			}
#ifdef DEBUG
			fprintf(outf, "MAKECH: 2: wx = %d, lx = %d\n", wx, lx);
#endif
			if (lx == wx + win->_begx)	/* if no change */
				break;
			lx = wx + win->_begx;
			if (lx >= COLS && AM) {
				lx = 0;
				ly++;
				/*
				 * xn glitch: chomps a newline after auto-wrap.
				 * we just feed it now and forget about it.
				 */
				if (XN) {
					(void) _putchar('\n');
					(void) _putchar('\r');
				}
			}
		} else if (wx <= lch)
			while (wx <= lch && *nsp == *csp) {
				nsp++;
				if (!curwin)
					csp++;
				++wx;
			}
		else
			break;
#ifdef DEBUG
		fprintf(outf, "MAKECH: 3: wx = %d, lx = %d\n", wx, lx);
#endif
	}
	return (OK);
}

/*
 * perform a mvcur, leaving standout mode if necessary
 */

DEBUGSTATIC void
domvcur(int oy, int ox, int ny, int nx)
{
	if (curscr->_flags & _STANDOUT && !MS) {
		(void) _puts(SE);
		curscr->_flags &= ~_STANDOUT;
	}
	(void) mvcur(oy, ox, ny, nx);
}