#!/usr/bin/perl

################################################################################
# Copyright 1998-1999 by Jens Lippmann (lippmann@rbg.informatik.th-darmstadt.de)
#
# Permission to use, copy, modify, and distribute this software for any
# purpose and without fee is hereby granted, provided that the above
# copyright notice appears in all copies. This software is provided "as is"
# and without any express or implied warranties.
#
#
# cweb2html, a converter for CWEB LaTeX to LaTeX2HTML parseable LaTeX.
#
# This program converts CWEB produced TeX and substitutes several
# plain TeX macros with LaTeX macros.
# The output may be translated with LaTeX2HTML.
# Use with LaTeX2HTML to translate HyTeX specific commands.
# Corresponding to HTMLMAC.STY, HTMLMAC.TEX, HTMLMAC.PERL.
#
# $Source: /home/latex2ht/cvs/latex2html/user/cweb2html/cweb2html,v $
# $RCSfile: cweb2html,v $
# $Revision: 1.2 $
# $Date: 1999/04/09 19:25:32 $
# $Author: JCL $
# $State: Exp $
#
# Handles:
# - TeX macros \.{  \?  \\{  \&{  \,  \)  \|  $<$  $>$  \1...\9
# - TeX macros   \X...\X
# - TeX macros in code section \T{  \vb{
# - math symbols in code section
#
# BUGS: - does not prevent \vb{} string substitution in \.{} environment
#       - does not avoid command substitution in \verb/../ strings.
#
################################################################################
# History
#
# $Log: cweb2html,v $
# Revision 1.2  1999/04/09 19:25:32  JCL
# changed my e-Mail address
#
# Revision 1.1  1998/02/24 02:29:49  latex2html
# for 98.1
#
# Revision 1.1  1998/02/24 02:15:28  latex2html
# ready for 98.1
#
# Revision 1.16  1997/06/25 01:45:32  lippmann
# debugged
#
# Revision 1.15  1997/06/05 16:12:19  lippmann
# styled argument handling, new synopsis (-b changed to -bc !)
# introduced -bak/+bak switch, -pretty changed to -fold/+fold
# improved help information (usage)
# new backup mechanism (stores files in backup directory instead tagging them)
# new folding mechanism (replaced awk script with improved Perl logic)
#
# Revision 1.14  1997/06/02 16:45:08  lippmann
# renamed PROCESSCWEBTEXOFF to CWEB2HTMLOFF.
# setting CWEB2HTMLOFF to 1 causes the script to behave like a dummy
#
# Revision 1.13  1997/06/02 16:07:18  lippmann
# renamed from ProcessCwebTex to cweb2html
#
# Revision 1.12  1997/06/01 11:57:41  lippmann
# removed (Cweb,Hyweb) mode selection, produces different include file
# names instead
#
# Revision 1.11  1997/06/01 08:19:08  lippmann
# adapted to new name space of htmlmac.sty:
#
# HTmode, HTpretty, HTnoderef -> HTCweb...
# HTweb -> HTCweb
# \ciao -> \HTCwebdocumentend
# 1 -> HTCweboneright
# 2 -> HTCweboneleft
# 3 -> HTCweboptbreak
# 4 -> HTCwebthisleft
# 5 -> HTCwebbigoptbreak
# 6 -> HTCwebbreak
# 7 -> HTCwebbigbreak
# 8 -> HTCwebclearleft
# 9 -> HTCwebempty
# idit -> HTCwebidit
# idma -> HTCwebidma
# idbo -> HTCwebidbo
# idtt -> HTCwebidtt
# discr -> HTCwebdiscr
# mathque -> HTCwebmathque
# smllspc -> HTCwebsmllspc
#
# Revision 1.10  1997/05/31 01:49:53  lippmann
# o \HTwebNodeRef has a new synopsis that allows to handle a refinement list
#   (multi-part refinements cited in the list of refinements)
# o tested with multi-part refinements in Cweb and Hyweb mode, works in
#   conjunction with new htmlmac.sty, htmlmac.perl
# o backward compatibility on by default, use +b to switch off (faster then)
#
# Revision 1.9  1997/05/25 21:16:04  lippmann
# o backward compatibility is on by defaults, switch of with '+b'
# o handles now \Xnum(, num)*:...\X, occurring in cweave generated list of
#   refinements with multi-part refinements
# o handling of multi-part refinements still is immature
#
# Revision 1.8  1997/02/27 13:49:57  lippmann
# handling of comments/verbatim much improved
#
# Revision 1.7  1997/02/26 03:24:03  lippmann
# reverted flaw in % line concatenation
#
# Revision 1.6  1997/02/09 15:34:49  lippmann
# fixed bug with \HTwebpar
#
# Revision 1.5  1997/02/09 15:26:20  lippmann
# allow our special hycweave to end code sections also with \cio
#
# Revision 1.4  1997/01/26 19:19:07  lippmann
# introduced -b (backwards compatibility) switch and fixed minor bugs
#
# Revision 1.3  1996/12/11 12:35:48  lippmann
# changed to get to work with Schrod's LaTeX CWEB
#  o handles now \X <num> : ... \X if <num> is non-zero
#  o sets an outer mode macro to cweb or hyweb depending on cwebmac.tex
#    or hywebmac.tex inclusion
#  o handles preliminary \end{document}
#  o \B -> \HTwebB
#  o \par -> \HTwebpar in code section (program state), was: \cio
#
# Revision 1.2  1996/09/24 03:26:53  lippmann
# env variable to switch off processing of the script should be used this way:
#     setenv PROCESSCWEBTEXOFF 1
#
# Revision 1.1.1.1  1996/07/08 15:46:29  liefke
# initial version for Darmstadt
#
# Revision 1.1.1.1  1996/07/08 15:36:06  liefke
# initial version for Darmstadt
#
# Revision 1.6  1996/06/20 02:22:09  lippmann
# - the parsing of \X..\X has a totally new face.
#   + is welded into HTweb macros
#   + newlines between \X and \X are handled much better
#
# - Synopsis changed:
#   + input file list now possible
#   + .tex is no more appended!
#
#
################################################################################

exit(0) if $ENV{'CWEB2HTMLOFF'};

# set this if awk cannot be found
$AUTHOR = "lippmann";
$DEBUG = 0;
$FOLD = 0;
$KEEPBAK = 0;
$BAKDIR = "bak";
$BACKCOMP = 1;
$DESTDIR = ".";
$SRCDIR = ".";
$DS = '/';
$FILE = undef;


$RCSID = '$Id: cweb2html,v 1.2 1999/04/09 19:25:32 JCL Exp $';
$RCSID =~ /[^ ]* ([^ ]*),v ([^ ]*) ([^ ]*) ([^ ]*) ([^ ]*) ([^ ]*)/;
$PRGFILE = $1;
$RCSFILE = "$1,v";
$RCSREV = $2;
$RCSDATE = $3;
$RCSTIME = $4;
$RCSAUTHOR = $5;
$RCSSTATE = $6;

while ($ARGV[0] =~ /^-/ && (! ($ARGV[0] =~ /^--$/)))
{
    $_ = shift;
    if (/^-dest_dir$/) {
	&mis_usage("<no arg for -dest_dir>") if !$ARGV[0];
	$DESTDIR = shift;
    } elsif (/^-fold$/) {
	$FOLD=1;
    } elsif (/^\+fold$/) {
	$FOLD=0;
    } elsif (/^-debug$/) {
	$DEBUG++;
    } elsif (/^\+debug$/) {
	$DEBUG=0;
    } elsif (/^-bc$/) {
	$BACKCOMP=1;
    } elsif (/^\+bc$/) {
	$BACKCOMP=0;
    } elsif (/^-bak$/) {
	$KEEPBAK=1;
    } elsif (/^\+bak$/) {
	$KEEPBAK=0;
    } elsif (/^-h|help/) {
	&help_usage;
    } else {
	&usage("<unknown option: $_>");
    }
}
&mis_usage("<no file name given>") if !$ARGV[0];

&main;

sub main {
    foreach $FILE (@ARGV) {
	# get leading path of file name and store in $SRCDIR
        if ($FILE =~ s/^(.*)$DS//) {
	    $SRCDIR = $1;
	} else {
	    $SRCDIR = ".";
	}
	print "$PRGFILE v$RCSREV -- Doing $FILE\n";
        &process_file;
    }
}

sub process_file {
    die "$PRGFILE: error: Could not find $SRCDIR/$FILE\n"
	unless -f "$SRCDIR/$FILE";

    if ($KEEPBAK) {
	mkdir("$DESTDIR/$BAKDIR",0755) unless -d "$DESTDIR/$BAKDIR";

	die "$PRGFILE: error: Could not create backup directory <$DESTDIR/$BAKDIR>\n"
	    unless -d "$DESTDIR/$BAKDIR";

	rename("$SRCDIR/$FILE", "$DESTDIR/$BAKDIR/$FILE") ||
	    die "$PRGFILE: error: Could not create backup file <$DESTDIR/$BAKDIR/$FILE>\n";
    }

    open(HELP,">&STDOUT");
    &slurp_file($KEEPBAK ? "$DESTDIR/$BAKDIR/$FILE" : "$SRCDIR/$FILE");
    # file must have been read before we open output (dest dir may be src dir)
    open (STDOUT, ">$DESTDIR/$FILE");
    &pass1;

    if ($FOLD) {
	# close associated file and restore STDOUT
	open (STDOUT, ">&HELP");
	&slurp_file("$DESTDIR/$FILE");
	open (STDOUT, ">$DESTDIR/$FILE");
	&pass2;
    }

    open (STDOUT, ">&HELP");
    close HELP;
}

# Reads the entire input file into a single string. 
sub slurp_file  {
    local($filename) = @_;
    local(%string);

    open(INPUT,"<$filename") ||
	die "$PRGFILE: error: Could not open $filename\n";

    while (<INPUT>) {
	$string{'STRING'} .= $_;
    }
    $_ = delete $string{'STRING'}; # Blow it away and return the result
}

sub pass1 {
    local($verbatim) = 0;
    local($code_section) = 0;

    # Change input files to hook in our HTWEB style.
    # The closing \n is for LaTeX2HTML bugs (percent after \input...)
    s/\\input\Whywebmac\W/\\input{htcwebhy}\n/;
    s/\\input\Wcwebmac\W/\\input{htcweb}\n/;

    local($contents) = $_;

    while ($contents =~ s/.*\n//) {
	$_ = $&;

	if (/^\s*%/) { # comment
	    print;
	}
	elsif (/\\begin\s*\{(LVerbatim|verbatim)\*?\}/) {
	    # fails if inside \verb !
	    $verbatim++;
	    print;
	}
	elsif (/\\end\s*\{(LVerbatim|verbatim)\*?\}/) {
	    # fails if inside \verb !
	    $verbatim--;
	    print;
	}
	elsif ($verbatim) {
	    print;
	}
	else {
	    # Concat lines truncated with % (percent sign).
	    # The % might be inserted by pass2 to make the lines readable.
	    # One reason yet to do this is compliance with LaTeX2HTML
	    # versions which do not recognize \foo in \foo% at end of line.
	    # Another reason is to get bubble names parsed trucated this way.
	    # Also, concat lines truncated with \ (occurs within \.{}).
	    # This will not be reversed, so awkward line lengthes can occur
	    # with verbatim strings of unusual length.
	    # This approach produces wrong results on:
	    # - % at line end and space, tab at next line:
	    #   leaves space, tab in the text (should be removed, too)
	    # - % at line end followed by an empty line:
	    #   results in one newline between the tokens (must be two, ie., \par)
	    #
	    while (s/([^\\]|^)((\\\\)*)%+[ \t]*\n/$1$2/ ||
		   s/([^\\]|^)((\\\\)*)\\\n/$1$2\\ /) {
		# peek and fetch next line if available
		$contents =~ s/(.*\n?)//;
		$_ .= $1;
	    }

	    if (s/([^\\]|^)\\B\\/$1\\HTCwebB\\/o) {$code_section = 1;}

	    # try first to convert \.{}, \\{}, \&{}, \?, \, and \)
	    # take care that \\, \& etc. in a \.{} or \vb{} macro are unaffected
	    # therefore handle contents of \.{} and \vb{} macros first
	    # Do double substitution to catch \vb{}\vb{} or \.{}\.{} (problem with [^\\|^])

	    # handle verbatim strings in \vb
		s/([^\\]|^)\\vb\{(([^\\\}]|\\.)*)\}/$1."\\vb {".&subst_verbatim($2)."}"/geo;
		s/([^\\]|^)\\vb\{(([^\\\}]|\\.)*)\}/$1."\\vb {".&subst_verbatim($2)."}"/geo;
	    # replace \.{ if not \\.{
		s/([^\\]|^)\\\.\{(([^\\\}]|\\.)*)\}/$1."\\HTCwebidtt{".&subst_verbatim($2)."}"/geo;
		s/([^\\]|^)\\\.\{(([^\\\}]|\\.)*)\}/$1."\\HTCwebidtt{".&subst_verbatim($2)."}"/geo;

	    # process the total (maybe new) line with the other macros
	    s/\\\?/\\HTCwebmathque/go;
	    s/\\\\\{/\\HTCwebidit\{/go;
	    s/\\\&\{/\\HTCwebidbo\{/go;
	    s/\\\,/\\HTCwebsmllspc/go;
	    s/\\\)/\\HTCwebdiscr/go;
	    s/\\\|(\\_|[a-zA-Z])/\\HTCwebidma\{$1\}/go;
	    s/\$<\$/</go; s/\$>\$/>/go;

	    # The \<num> commands must get parsed order-sensitive.
	    # This is not done by LaTeX2HTML when they occur
	    # within others.
	    s/\\hbox\{\\(\d+)\}/\\\1/go;

	    if ($BACKCOMP) {
		s/\\1/\\HTCweboneright/go;
		s/\\2/\\HTCweboneleft/go;
		s/\\3([0-9])/\\HTCweboptbreak{$1}/go;
		s/\\4/\\HTCwebthisleft/go;
		s/\\5/\\HTCwebbigoptbreak/go;
		s/\\6/\\HTCwebbreak/go;
		s/\\7/\\HTCwebbigbreak/go;
		s/\\8/\\HTCwebclearleft/go;
		s/\\9/\\HTCwebempty/go;
	    }

# a kludge to spoof LaTeX2HTML
	    s/^\\end\{document\}$/\\HTCwebdocumentend/;

	    if ($code_section) {
		local($pre,$value);
		# replace unmasked dollars with alternate math sign
		# we don't care of \\$ (\\ at EOL) here
		# Do it twice to catch $$ (display math, maybe in comments)
		s/([^\\]|^)\$/$1\~/g;
		s/([^\\]|^)\$/$1\~/g;
# we need a better 'end of code section' marker than
# provided by CWEB.
# This delimits \B both in htmlmac.sty and htmlmac.perl.
		s/\\(par|cio)$/\\HTCwebpar/;
	    }
	    # handle escape command for constants
	    s/([^\\]|^)\\T\{([^\}]*)\}/$1."\\T\{".&subst_const($2)."\}"/geo;

	    # replace $\X...\X$ resp. \X...\X with \HTCwebNodeRef{..}{..}{..}
	    # this task must be done *after* dollar signs are handled


	    # revert $ conversion for \PB{~\X((not \X)*)\X~} (must occur in 1 line)
	    s/\\PB\{\~\\X(([^\\]|(\\[^X]))*)\\X\~\}/\\PB\{\$\\X$1\\X\$\}/go;

	    # and rip out \PB. This is necessary to get catcodes working, i.e.
	    # \X...\X must not be subjected as argument to any macro.
	    # This is a kludge to get it working with LaTeX CWEB, where \PB is
	    # defined for 'restricted program mode', but cwebmac.tex defines it
	    # to \relax nevertheless.
	    s/\\PB(\{[\~\$]?\\X)/$1/g unless $code_section;

	    # handle \X...\X null refs of HYWEB resp. normal refs of CWEB
	    # handle case that a newline may appear between \X...\X
	    while (/(\$)?\\X([\d, ]+):(\\underline\{\\HTCwebidbo\{)?/) {
		local($before,$after,$math,$labellist,$pretty) = ($`,$',$1,$2,$3);
		# There must be an '\\X' following
		$math = '\$' if $math;
		$pretty = '\}\}' if $pretty;
		local($cmdtail);
		# we need this tail only for external references
		$cmdtail = '~\\HTCwebX'
		    unless $labellist;

		if (!($after =~ s/$pretty\\X$math/\}$cmdtail/)) {
		    # go beyond end of line to substitute!
		    $contents =~ s/$pretty\\X$math/\}$cmdtail/;
		}
		if ($labellist) {
		    # In Cweb, $labellist may be a comma separated list of numbers.
		    # (multiply occurring refinements are handled this way in the
		    # list of refinements).
		    # Make comma separated list with elements {section_<no>}{<no>}.
		    $labellist =~ s/(\d+)/\{section_$1\}\{$1\}/g;

		    $_ = join('',$before,"\\HTCwebNodeRef\{",$labellist,"\}\{",$after);
		} else {
		    $_ = join('',$before,"\\HTCwebX~\\HTCwebNodeRefExt\{",$after);
		}
	    }

	    # then, care of \X...\X normal refs for HYWEB
	    while (/(\$?)\\X((\\noderef\{[^\}]*\}\{[^\}]*\}(, )?)+):\\underline\{\\HTCwebidbo\{/) {
		local($before,$after,$math,$labellist) = ($`,$',$1,$2);
		# There must be an '\\X' following
		$math =~ s/\$/\\\$/;
		if (!($after =~ s/\}\}\\X$math/\}/)) {
		    # go beyond end of line to substitute!
		    $contents =~ s/\}\}\\X$math/\}/;
		}
		$labellist =~ s/\\noderef//g;
		$_ = join('',$before,"\\HTCwebNodeRef\{",$labellist,"\}\{",$after);
	    }


	    if (/\\HTCwebpar$/) {$code_section = 0;}
	    print;
	}
    }
}

sub subst_const {
    local($_) = @_;

    s/\\\^/{\\hex}/g;
    s/\\\~/{\\oct}/g;
    $_;
}

sub subst_verbatim {
    local($_) = @_;

    s/\\\\/\{\\BS\}/g;
    s/\\\{/\{\\LB\}/g;
    s/\\\}/\{\\RB\}/g;
    s/\\~/\{\\TL\}/g;
    s/\\ /\{\\SP\}/g;
    s/\\_/\{\\UL\}/g;
    s/\\&/\{\\AM\}/g;
    s/\\\^/\{\\CF\}/g;
    $_;
}


# Parse file in $_ and truncate long lines with percent signs to improve
# readability of output.
# Precondition: Percents at end of non-comment lines cannot occur, because such
# lines are concatenated during pass one.
#
sub pass2 {
    local($verbatim) = 0;
    local($contents) = $_;

    while ($contents =~ s/.*\n//) {
	$_ = $&;

	if (/^\s*%/) {	# comment
	    print;
	}
	elsif (/\\begin\s*\{(LVerbatim|verbatim)\*?\}/) {
	    # fails if inside \verb !
	    $verbatim++;
	    print;
	}
	elsif (/\\end\s*\{(LVerbatim|verbatim)\*?\}/) {
	    # fails if inside \verb !
	    $verbatim--;
	    print;
	}
	elsif ($verbatim) {
	    print;
	}
	elsif (length >= 80) {
	    if (/((^|[^\\])(\\\\)*)\\verb/) {
		# long line containing \verb, try to break before or forget it
		if (length($`) || length($1)) {
		    print $`, $1, "%\n\\verb", $';
		} else {
		    print;
		}
	    } else {
		# long line without \verb, banzai!

		if (s/((^|[^\\])(\\\\)*)(%+)/$1%\n/) {
		    local($comment) = $4.$';
		    # we have a semi-line comment.
		    # take it to a single line and shorten remainder.
		    # this saves false breakpoint detection in comments.
		    &cutline;
		    print $_, $comment;
		} else {
		    &cutline;
		    print;
		}
	    }
	} else {
	    print;
	}
    }
}


# Cut line longer than 79 chars (included the trailing newline) by
# finding a breakpoint and inserting a %.
# Strategy: find all breakpoints occurring < 80 chars, choose last one
# before 70. char if exists, else next one if exists, else do no break.
# A breakpoint is any unmasked opening/closing brace not followed
# by white space (is precious here!) or % (comment lines are already
# handled) and not occurring at line end.
# Preconditions:
# a) line must not be or end with a comment (=> false break)
# b) catcoded {, } (=> false break)
# Modifies $_.
#
sub cutline {
    while (length >= 80) {
	local($pre,$pat,$aft,$idx,$lastidx,$done,$lastdone);

	while (/((^|[^\\])(\\\\)*)(\{|\})([^\s%])/) {
	    ($pre,$pat,$aft) = ($`.$1,$4,$5.$');
	    $done .= $pre . $pat;
	    $idx = length($done);
	    $_ = $aft;
	    last if $idx >= 70;
	    $lastdone = $done;
	    $lastidx = $idx;
	}

	if (!$idx) {
	    # found no breakpoint at all, out
	    return;
	} elsif ($idx < 70) {
	    # found no suitable break above 69. char
	    print $done, "%\n";
	} elsif ($idx < 80) {
	    # found perfect breakpoint
	    print $done, "%\n";
	} elsif ($lastidx) {
	    # breakpoint above 79. char and breakpoint below 70., take latter
	    print $lastdone, "%\n";
	    $_ = join('', $pre, $pat, $aft);
	} else {
	    # single breakpoint above 79. char, take it
	    print $done, "%\n";
	}
    }
}


sub help_usage {
    print "Booting <help> system, please stand by...\n\n";
    print "HLP% $PRGFILE internal help system Version 7.6plus \"rightsized\"\n";
    print "HLP% User requested       : <help>.\n";
    print "HLP% Available ressources : <help>.\n";
    print "HLP% Activating           : <help>.\n";
    print "HLP% Have a nice day!\n";
    &usage;
}

sub mis_usage {
    print "AAAAAAAAAAAAAAAAAAAAAAArgh!!!!\n";
    print "You didn't invoke me the right way. Watch the error message below!\n\n";
    &usage;
}

sub usage {
    print (<<"_USAGE_");

RCS version:
  $RCSFILE Rev $RCSREV by $AUTHOR (last change $RCSDATE by $RCSAUTHOR)
Usage:
  $PRGFILE [+-bc] [+-bak] [+-debug] [-dest_dir <dest_dir>] [+-fold] [-h[elp]]
           <file> [more_files]
  where <dest_dir> specifies output directory and <file> may have a full path
  name specification. The arguments denoted with [ ] backets are optional.
  Giving an option with - sets it on, and + turns it definitely off.

  For each given <file>, this perl script processes the Cweb-like TeX contents
  and stores the result in <dest_dir>/<file>. The resulting file works together
  with htcweb.sty and can be fed into LaTeX2HTML to produce HTML output.
Options:
  -bc
  +bc
      Set/Unset backwards compatiblity to LaTeX2HTML releases 95.3 and 96.1x.
      Set by default.
  -bak
  +bak
      Keep/Discard original input files in backup directory. If they should be
      kept, they are stored in a backup direcory in <dest_dir>. Else if they
      should be discarded, original files will be overwritten unless
      <dest_dir> differs from the residing directory of the original file.
      Discards them by default.
  -debug
  +debug
      Sets/Zeroes debug level (reserved). Debug level is 0 by default.
  -dest_dir
      Specifies directory where to store the output files.
  -fold
  +fold
      If on, lines of the output file longer than 80 chars are broken with %.
      This may cause insertion of a space in HTML output with older LaTeX2HTML
      versions. Off by default.
  -h
  -help
      Prints this.
_USAGE_

    die("\n$PRGFILE: @_\n") if @_;
    exit(1);
}