#!/usr/bin/perl
#
#   Program to process specially coded LaTex files
#   to generate multiple versions of the document.
#   For example, lecture notes, slides, and partial
#   lecture notes from the same source file.
#
# Special commands of the form <XXX>  can be inserted
# in the first column of lines in the LaTex document
# to control which lines go to which streams.
# Streams are named by a single letter.
#
# Defined in terms of Perl regexps, the commands are:
# ^<stream,[ \t]*(\w)>        # define a new stream
# ^<\*([a-zA-Z]+)>            # set default output
# ^<\*>                       # set default output to all streams
# ^<([a-zA-Z]+)>              # send this line to specific streams
# ^<\!([a-zA-Z]+)>            # block this line from specific streams
#
#  Command line options:
#
#       --out [hsn]     ! select one output stream (single character)
#       --quiet         ! discard other streams (default is comment)
#       --tex           ! automate the latex command
#       --clean         ! clean up the latex mess and the .[nhs].tex file
#
#  $st selects the default output stream to be generated when
#      this program is run on a file
#
#       Blake Hannaford
#       University of Washington
#       June 2001
#
use Getopt::Long;
$ifhandle = 1239817239187;
$ofhandle = 89120398230487;

%optctl = ("out=s" => \$st, "quiet"=> \$q);

#$st = "h";       # "handouts"
$st = "s";        # "slides"
#$st = "n";       # "notes"

#&GetOptions(\%optctl);
if(&GetOptions("out=s" => \$st, "quiet"=> \$q, "clean"=> \$cl, "tex"=> \$te) == 0 ) {
print STDERR <<XXXX;

 coursetex  -- a processor for generating multiple versions
                (e.g. slides, notes, handouts)
               from a single latex document.

 usage:   courstex [filename] [--options]

   output file is filename.[hsn].tex
   if no filename STDIN and STDOUT are used
   options:
       --out [hsn]     ! select one output stream (single character)
       --quiet         ! discard other streams (default is comment)

XXXX

exit 1;
}

#print STDERR "\@ARGV[0] = @ARGV[0], \@ARGV[1] = @ARGV[1]\n" ;
#print STDERR @ARGV[0];
#print STDERR "\n";

#
#  Get filename from command line if present or default
#      to STDIN/STDOUT
#
if(@ARGV[0] ne "") { $fname = @ARGV[0];
               if(open($ifhandle,$fname)){
                   $fname1 = $fname;
                   $fname1 =~ s/\..*/\./;                      # get rid of extension
                   $fname1 = $fname1 . $st . ".tex" ;
                   open($ofhandle, ">" . $fname1);             # create output file
                   }
               else{print STDERR "Sorry, can't find or open $fname \n"; die;}
               }
else{$ifhandle = STDIN; $ofhandle = STDOUT; }

$line = 0;

$valid_streams  = "nhs";                # the (pre)defined streams
$active_streams = $valid_streams;       # default streams

while (<$ifhandle>)
  {
   chomp;
   $line++;
   $sok = 1;              # syntax OK for generic lines
   $cmd = 0;              # storage for possible stream command

   $this_line = $active_streams;      # streams for current line

   if(m/(^<.*>)/) {   # Analyze stream control commands
      $cmd =  $1 ;                # store the command
      $sok = 0;                   # assume syntax error unless match below

      if(m/^<stream,[ \t]*(\w)>/) {        # define a new stream
          if(index($valid_streams, $1) < 0) {
              $valid_streams .= $1; }
          #print STDERR "   valid streams:", $valid_streams, "\n";
          $sok++; }

 #     if(m/^<command,[ \t]*(\w),[ \t]*\"(.*)\"[ \t]*>/) {        # accept a processing command for a stream
 #         @commands($1) = $2;
 #         #print STDERR "   Command: $1,$2", "\n";
 #         $sok++; }

      if(m/^<\*([a-zA-Z]+)>/){             # set default output
          $active_streams = $this_line = $1;
          $sok++;}

      if(m/^<\*>/){                     # set all streams to default output
          $active_streams = $this_line = $valid_streams;
          $sok++;}

      if(m/^<([a-zA-Z]+)>/){               # send this line to specific streams
          $this_line= $1 ;
          #print STDERR "    current line to: ", $this_line, "\n";
          $sok++;}

      if(m/^<\!([a-zA-Z]+)>/){             # block this line from specific streams
          $this_line =~ s/$1// ;
          #print STDERR "    current line to: ", $this_line, "\n";
          $sok++;}

      if($sok == 1){ s/(^<.*>)// ; }        # clear the command
      }

   if($sok == 0) {print STDERR "Coursetex syntax error: [line ", $line, "] ", $_, "\n";
                  $this_line = 0;  }

   # print STDERR "[", "$this_line",      "] ", $_ , "\n" ;

   if(index($this_line, $st) < 0)   # if not in stream
        {
        if($q ==0){  #and not quiet mode
               print $ofhandle "%" ;                             # comment out lines NOT in this stream
               if($sok == 1 && $cmd != 0){print $ofhandle $cmd ;}        # restore the command if cleared
               print $ofhandle  $_;
               print $ofhandle  "\n";
               }
        }
   else {    # this line is IN the current stream
        print $ofhandle  $_  ;        # print the line  
        if($cmd ne 0  )
            {print $ofhandle "\t%",$cmd}     # tack command onto end as a comment
        print $ofhandle  "\n";
        }

 }

close($ofhandle);
close($ifhandle);

if($te == 1)  { system ("latex $fname1\n");
               $fnameroot = $fname1;
               $fnameroot =~ s/\.tex//;                     # truncate file name
               if($cl != 0) {system("mv $fnameroot.log junk");
                             system("mv $fnameroot.aux junk");
                             #system("mv $fnameroot.");  # clean up junk files
                             }
               }

exit 1;