/*	$NetBSD: fmt.c,v 1.17 2003/08/07 11:13:47 agc 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. 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.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1980, 1993\n\
	The Regents of the University of California.  All rights reserved.\n");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)fmt.c	8.1 (Berkeley) 7/20/93";
#endif
__RCSID("$NetBSD: fmt.c,v 1.17 2003/08/07 11:13:47 agc Exp $");
#endif /* not lint */

#include <ctype.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/*
 * fmt -- format the concatenation of input files or standard input
 * onto standard output.  Designed for use with Mail ~|
 *
 * Syntax : fmt [ goal [ max ] ] [ name ... ]
 * Authors: Kurt Shoens (UCB) 12/7/78;
 *          Liz Allen (UMCP) 2/24/83 [Addition of goal length concept].
 */

/* LIZ@UOM 6/18/85 -- Don't need LENGTH any more.
 * #define	LENGTH	72		Max line length in output
 */
#define	NOSTR	((char *) 0)	/* Null string pointer for lint */

/* LIZ@UOM 6/18/85 --New variables goal_length and max_length */
#define GOAL_LENGTH 65
#define MAX_LENGTH 75
int	goal_length;		/* Target or goal line length in output */
int	max_length;		/* Max line length in output */
int	pfx;			/* Current leading blank count */
int	lineno;			/* Current input line */
int	mark;			/* Last place we saw a head line */
int	center;

char	*headnames[] = {"To", "Subject", "Cc", 0};

static void	fmt(FILE *);
static int	ispref(const char *, const char *);
static void	leadin(void);
static void	oflush(void);
static void	pack(const char *, int);
static void	prefix(const char *, int);
static void	setout(void);
static void	split(const char *, int);
static void	tabulate(char *);

int	ishead(const char *);
int	main(int, char **);

/*
 * Drive the whole formatter by managing input files.  Also,
 * cause initialization of the output stuff and flush it out
 * at the end.
 */

int
main(int argc, char **argv)
{
	FILE *fi;
	int errs = 0;
	int number;		/* LIZ@UOM 6/18/85 */

	goal_length = GOAL_LENGTH;
	max_length = MAX_LENGTH;
	setout();
	lineno = 1;
	mark = -10;

	setlocale(LC_ALL, "");

	/*
	 * LIZ@UOM 6/18/85 -- Check for goal and max length arguments 
	 */
	if (argc > 1 && !strcmp(argv[1], "-C")) {
		center++;
		argc--;
		argv++;
	}
	if (argc > 1 && (1 == (sscanf(argv[1], "%d", &number)))) {
		argv++;
		argc--;
		goal_length = abs(number);
		if (argc > 1 && (1 == (sscanf(argv[1], "%d", &number)))) {
			argv++;
			argc--;
			max_length = abs(number);
		}
	}
	if (max_length <= goal_length) {
		fprintf(stderr, "Max length must be greater than %s\n",
			"goal length");
		exit(1);
	}
	if (argc < 2) {
		fmt(stdin);
		oflush();
		exit(0);
	}
	while (--argc) {
		if ((fi = fopen(*++argv, "r")) == NULL) {
			perror(*argv);
			errs++;
			continue;
		}
		fmt(fi);
		fclose(fi);
	}
	oflush();
	exit(errs);
}

/*
 * Read up characters from the passed input file, forming lines,
 * doing ^H processing, expanding tabs, stripping trailing blanks,
 * and sending each line down for analysis.
 */
static void
fmt(FILE *fi)
{
	char linebuf[BUFSIZ], canonb[BUFSIZ];
	char *cp, *cp2;
	int c, col, add_space;

	if (center) {
		while (1) {
			cp = fgets(linebuf, BUFSIZ, fi);
			if (!cp)
				return;
			while (*cp && isspace(*cp))
				cp++;
			cp2 = cp + strlen(cp) - 1;
			while (cp2 > cp && isspace(*cp2))
				cp2--;
			if (cp == cp2)
				putchar('\n');
			col = cp2 - cp;
			for (c = 0; c < (goal_length-col)/2; c++)
				putchar(' ');
			while (cp <= cp2)
				putchar(*cp++);
			putchar('\n');
		}
	}
	c = getc(fi);
	while (c != EOF) {
		/*
		 * Collect a line, doing ^H processing.
		 * Leave tabs for now.
		 */
		cp = linebuf;
		while (c != '\n' && c != EOF && cp-linebuf < BUFSIZ-1) {
			if (c == '\b') {
				if (cp > linebuf)
					cp--;
				c = getc(fi);
				continue;
			}
			if(!(isprint(c) || c == '\t' || c >= 160)) {
				c = getc(fi);
				continue;
			}
			*cp++ = c;
			c = getc(fi);
		}
		*cp = '\0';

		/*
		 * By default, add space after the end of current input
		 * (normally end of line)
		 */
		add_space = 1;

		/*
		 * If the input line is longer than linebuf buffer can hold,
		 * process the data read so far as if it was a separate line -
		 * if there is any whitespace character in the read data,
		 * process all the data up to it, otherwise process all.
		 */
		if (c != '\n' && c != EOF && !isspace(c)) {
			/*
			 * Find out if any whitespace character has been read.
			 */
			for(cp2 = cp; cp2 >= linebuf
				&& !isspace((unsigned char)*cp2); cp2--);

			if (cp2 < linebuf) {
				/*
				 * ungetc() last read character so that it
				 * won't get lost.
				 */
				ungetc(c, fi);
				/*
				 * Don't append space on the end in split().
				 */
				add_space = 0;
			} else {
				/*
				 * To avoid splitting a word in a middle,
				 * ungetc() all characters after last
				 * whitespace char.
				 */
				while (!isspace(c) && (cp >= linebuf)) {
					ungetc(c, fi);
					c = *--cp;
				}
				*cp = '\0';
			}
		}
		
		/*
		 * Expand tabs on the way to canonb.
		 */
		col = 0;
		cp = linebuf;
		cp2 = canonb;
		while ((c = *cp++) != 0) {
			if (c != '\t') {
				col++;
				if (cp2-canonb < BUFSIZ-1)
					*cp2++ = c;
				continue;
			}
			do {
				if (cp2-canonb < BUFSIZ-1)
					*cp2++ = ' ';
				col++;
			} while ((col & 07) != 0);
		}

		/*
		 * Swipe trailing blanks from the line.
		 */
		for (cp2--; cp2 >= canonb && *cp2 == ' '; cp2--)
			;
		*++cp2 = '\0';
		prefix(canonb, add_space);
		if (c != EOF)
			c = getc(fi);
	}
}

/*
 * Take a line devoid of tabs and other garbage and determine its
 * blank prefix.  If the indent changes, call for a linebreak.
 * If the input line is blank, echo the blank line on the output.
 * Finally, if the line minus the prefix is a mail header, try to keep
 * it on a line by itself.
 */
static void
prefix(const char line[], int add_space)
{
	const char *cp;
	char **hp;
	int np, h;

	if (strlen(line) == 0) {
		oflush();
		putchar('\n');
		return;
	}
	for (cp = line; *cp == ' '; cp++)
		;
	np = cp - line;

	/*
	 * The following horrible expression attempts to avoid linebreaks
	 * when the indent changes due to a paragraph.
	 */
	if (np != pfx && (np > pfx || abs(pfx-np) > 8))
		oflush();
	if ((h = ishead(cp)) != 0)
		oflush(), mark = lineno;
	if (lineno - mark < 3 && lineno - mark > 0)
		for (hp = &headnames[0]; *hp != (char *) 0; hp++)
			if (ispref(*hp, cp)) {
				h = 1;
				oflush();
				break;
			}
	if (!h && (h = (*cp == '.')))
		oflush();
	pfx = np;
	if (h) {
		pack(cp, strlen(cp));
		oflush();
	} else
		split(cp, add_space);
	lineno++;
}

/*
 * Split up the passed line into output "words" which are
 * maximal strings of non-blanks with the blank separation
 * attached at the end.  Pass these words along to the output
 * line packer.
 */
static void
split(const char line[], int add_space)
{
	const char *cp;
	char *cp2;
	char word[BUFSIZ];
	int wordl;		/* LIZ@UOM 6/18/85 */

	cp = line;
	while (*cp) {
		cp2 = word;
		wordl = 0;	/* LIZ@UOM 6/18/85 */

		/*
		 * Collect a 'word,' allowing it to contain escaped white
		 * space. 
		 */
		while (*cp && *cp != ' ') {
			if (*cp == '\\' && isspace((unsigned char)cp[1]))
				*cp2++ = *cp++;
			*cp2++ = *cp++;
			wordl++;/* LIZ@UOM 6/18/85 */
		}

		/*
		 * Guarantee a space at end of line. Two spaces after end of
		 * sentence punctuation. 
		 */
		if (*cp == '\0' && add_space) {
			*cp2++ = ' ';
			if (strchr(".:!", cp[-1]))
				*cp2++ = ' ';
		}
		while (*cp == ' ')
			*cp2++ = *cp++;
		*cp2 = '\0';
		/*
		 * LIZ@UOM 6/18/85 pack(word); 
		 */
		pack(word, wordl);
	}
}

/*
 * Output section.
 * Build up line images from the words passed in.  Prefix
 * each line with correct number of blanks.  The buffer "outbuf"
 * contains the current partial line image, including prefixed blanks.
 * "outp" points to the next available space therein.  When outp is NOSTR,
 * there ain't nothing in there yet.  At the bottom of this whole mess,
 * leading tabs are reinserted.
 */
char	outbuf[BUFSIZ];			/* Sandbagged output line image */
char	*outp;				/* Pointer in above */

/*
 * Initialize the output section.
 */
static void
setout(void)
{
	outp = NOSTR;
}

/*
 * Pack a word onto the output line.  If this is the beginning of
 * the line, push on the appropriately-sized string of blanks first.
 * If the word won't fit on the current line, flush and begin a new
 * line.  If the word is too long to fit all by itself on a line,
 * just give it its own and hope for the best.
 *
 * LIZ@UOM 6/18/85 -- If the new word will fit in at less than the
 *	goal length, take it.  If not, then check to see if the line
 *	will be over the max length; if so put the word on the next
 *	line.  If not, check to see if the line will be closer to the
 *	goal length with or without the word and take it or put it on
 *	the next line accordingly.
 */

/*
 * LIZ@UOM 6/18/85 -- pass in the length of the word as well
 * pack(word)
 *	char word[];
 */
static void
pack(const char word[], int wl)
{
	const char *cp;
	int s, t;

	if (outp == NOSTR)
		leadin();
	/*
	 * LIZ@UOM 6/18/85 -- change condition to check goal_length; s is the
	 * length of the line before the word is added; t is now the length
	 * of the line after the word is added
	 *	t = strlen(word);
	 *	if (t+s <= LENGTH) 
	 */
	s = outp - outbuf;
	t = wl + s;
	if ((t <= goal_length) ||
	    ((t <= max_length) && (t - goal_length <= goal_length - s))) {
		/*
		 * In like flint! 
		 */
		for (cp = word; *cp; *outp++ = *cp++);
		return;
	}
	if (s > pfx) {
		oflush();
		leadin();
	}
	for (cp = word; *cp; *outp++ = *cp++);
}

/*
 * If there is anything on the current output line, send it on
 * its way.  Set outp to NOSTR to indicate the absence of the current
 * line prefix.
 */
static void
oflush(void)
{
	if (outp == NOSTR)
		return;
	*outp = '\0';
	tabulate(outbuf);
	outp = NOSTR;
}

/*
 * Take the passed line buffer, insert leading tabs where possible, and
 * output on standard output (finally).
 */
static void
tabulate(char line[])
{
	char *cp;
	int b, t;

	/*
	 * Toss trailing blanks in the output line.
	 */
	cp = line + strlen(line) - 1;
	while (cp >= line && *cp == ' ')
		cp--;
	*++cp = '\0';
	
	/*
	 * Count the leading blank space and tabulate.
	 */
	for (cp = line; *cp == ' '; cp++)
		;
	b = cp-line;
	t = b >> 3;
	b &= 07;
	if (t > 0)
		do
			putc('\t', stdout);
		while (--t);
	if (b > 0)
		do
			putc(' ', stdout);
		while (--b);
	while (*cp)
		putc(*cp++, stdout);
	putc('\n', stdout);
}

/*
 * Initialize the output line with the appropriate number of
 * leading blanks.
 */
static void
leadin(void)
{
	int b;
	char *cp;

	for (b = 0, cp = outbuf; b < pfx; b++)
		*cp++ = ' ';
	outp = cp;
}

/*
 * Is s1 a prefix of s2??
 */
static int
ispref(const char *s1, const char *s2)
{

	while (*s1++ == *s2)
		;
	return (*s1 == '\0');
}