/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

#include <stdio.h>
#include <locale.h>
#include <wchar.h>
#include <euc.h>
#include <stdlib.h>		/* XCU4 */
#include <limits.h>
#include <libintl.h>
#include <langinfo.h>
#include <utime.h>
#include <widec.h>
#include <wctype.h>
#include <errno.h>


/*
 * fold - fold long lines for finite output devices
 */

static int fold =  80;
static int bflg = 0;
static int sflg = 0;
static int wflg = 0;
static int lastc = 0;
static int col = 0;
static int ncol = 0;
static int spcol = 0;
static wchar_t line[LINE_MAX];
static wchar_t *lastout = line;
static wchar_t *curc = line;
static wchar_t *lastsp = NULL;
#define	MAXARG _POSIX_ARG_MAX

/*
 * Fix lint errors
 */
void exit();
static void Usage();
static void putch();
static void newline_init();
static int chr_width();
extern int errno;
static int get_foldw();


int
main(int argc, char *argv[])
{
	int c, narg;
	int ch;
	char *cmdline[MAXARG];
	int	new_argc;
	int w;
	extern int optind;
	extern char *optarg;

	(void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)
#define	TEXT_DOMAIN "SYS_TEST"
#endif
	(void) textdomain(TEXT_DOMAIN);

	/*
	 * Parse -width separately and build
	 * the new command line without -width.
	 * Next, use getopt() to parse this
	 * new command line.
	 */

	for (narg = new_argc = 0; narg < argc; narg ++) {
		if (argv[narg][0] == '-' &&
			isdigit(argv[narg][1])) {

			if (get_foldw((char *)&argv[narg][1], &w) < 0)
				exit(1);

			fold = w;	/* Update with new width */
		} else {
			/* Build the new command line */
			cmdline[new_argc++] = argv[narg];

			/*
			 * Check to make sure the option with
			 * required arg should have arg.
			 * This would check errors introduced in
			 * mixing non-getopt() options and that of
			 * getopt()'s due to stripping non-getopt
			 * options.
			 */
			if ((argv[narg][0] == '-') && (argv[narg][1] == 'w')) {
				if (((narg+1) < argc) &&
					(argv[narg+1][0] == '-')) {
					(void) fprintf(stderr, "fold");
					(void) fprintf(stderr, gettext(
				": option requires an argument -- w\n"));
					Usage();
					exit(1);
				}
			}
		}
	}

	while ((ch = getopt(new_argc, cmdline, "w:bs")) != EOF) {
		switch (ch) {
			case 'b':
				bflg++;
				break;
			case 's':
				sflg++;
				break;
			case 'w':
				wflg++;
				/* No required arg ? */
				if ((optarg == (char *)NULL) ||
					((optarg != (char *)NULL) &&
					(*optarg == '-'))) {
						(void) fprintf(stderr, "fold");
						(void) fprintf(stderr, gettext(
				": option requires an argument -- w\n"));
						Usage();
						exit(1);
				}
				/* Bad number ? */
				if (get_foldw(optarg, &w) < 0)
					exit(1);

				fold = w;
				break;
			default:
				/*
				 * Errors should be filtered in previous
				 * pass.
				 */
				Usage();
				exit(1);
		} /* switch */
	} /* while */

	do {
		if (new_argc > optind) {
			if (freopen(cmdline[optind], "r", stdin) == NULL) {
				perror(cmdline[optind]);
				Usage();
				exit(1);
			}
			optind++;
		}

		for (;;) {
			c = getwc(stdin);
			if (c == EOF)
				break;
			(void) putch(c);
			lastc = c;
		}
		if (col != 0) newline_init();
	} while (new_argc > optind);

	return (0);
}

static void
putch(int c)
{
	wchar_t tline[LINE_MAX];

	switch (c) {
		case '\n':
			ncol = 0;
			break;
		case '\t':
			if (bflg)
				ncol = col + chr_width(c);
			else
				ncol = (col + 8) &~ 7;
			break;
		case '\b':
			if (bflg)
				ncol = col + chr_width(c);
			else
				ncol = col ? col - 1 : 0;
			break;
		case '\r':
			if (bflg)
				ncol = col + chr_width(c);
			else
				ncol = 0;
			break;

		default:
			if (bflg)
				ncol = col + chr_width(c);
			else
				ncol = col + wcwidth(c);

	}

	/*
	 * Special processing when -b is not specified
	 * for backspace, and carriage return.
	 * No newline is inseted before or after the
	 * special character: backspace, or cr.
	 * See man page for the handling of backspace
	 * and CR when there is no -b.
	 */
	if ((ncol > fold) && (bflg ||
		(!bflg && (lastc != '\b') && (c != '\b') &&
		(lastc != '\n') && (c != '\n'))))  {
		/*
		 * Need to check the last position for blank
		 */
		if (sflg && lastsp) {
			/*
			 * Save the output buffer
			 * as NULL has to be insert into the last
			 * sp position.
			 */
			(void) wscpy(tline, line);
			*lastsp = (wchar_t)NULL;
			(void) fputws(lastout, stdout);
			(void) putwchar('\n');
			/*
			 * Restore the output buffer to stuff
			 * NULL into the last sp position
			 * for the new line.
			 */
			(void) wscpy(line, tline);
			lastout = lastsp;
			lastsp = NULL;	/* Reset the last sp */
			ncol -= spcol;	/* Reset column positions */
			col -= spcol;
		} else {
			(void) newline_init();
			(void) putwchar('\n');
			lastout = curc;
		}
	}
	/* Output buffer is full ? */
	if ((curc + 1) >= (line + LINE_MAX)) {
		/* Reach buffer limit */
		if (col > 0) {
			*curc = (wchar_t)NULL;
			(void) fputws(lastout, stdout);
			lastsp = NULL;
		}
		curc = lastout = line;

	}

	/* Store in output buffer */
	*curc++ = (wchar_t)c;

	switch (c) {
		case '\n':
			(void)  newline_init();
			curc = lastout = line;
			break;
		case '\t':
			if (bflg)
				col = col + chr_width(c);
			else
				col = (col + 8) &~ 7;
			if (sflg && iswspace(c)) {
				lastsp = curc;
				spcol = ncol;
			}

			break;
		case '\b':
			if (bflg)
				col = ncol;
			else {
				if (col)
					col--;
			}
			break;
		case '\r':
			col = 0;
			break;
		default:
			if (sflg && iswspace(c)) {
				lastsp = curc;
				spcol = ncol;
			}

			if (bflg)
				col += chr_width(c);
			else
				col += wcwidth(c);

			break;
	}
}
static
void
Usage()
{
	(void) fprintf(stderr, gettext(
	    "Usage: fold [-bs] [-w width | -width ] [file...]\n"));
}

static
void
newline_init()
{
	*curc = (wchar_t)NULL;
	(void) fputws(lastout, stdout);
	ncol = col = spcol = 0;
	lastsp = NULL;
}

static int
chr_width(c)
register int c;
{
	char chr[MB_LEN_MAX+1];
	register int	n;

	n = wctomb(chr, (wchar_t)c);

	return (n > 0 ? n : 0);
}

static int
get_foldw(toptarg, width)
char	*toptarg;
int		*width;
{
	char	*p;

	if (!toptarg)
		goto badno;

	*width = 0;
	errno = 0;
	*width = strtoul(toptarg, &p, 10);
	if (*width == -1)
		goto badno;

	if (*p)
		goto badno;

	if (!*width)
		goto badno;

	return (0);

badno:
	/* fold error message */
	(void) fprintf(stderr, gettext(
		"Bad number for fold\n"));
	Usage();
	return (-1);
}