#!/usr/local/bin/perl 
#
# Gateway script to convert some sample LaTeX files into HTML "on the fly"
# using the LaTeX2HTML translator.
#
# Written by Nikos Drakos (nikos@cbl.leeds.ac.uk)
# 26-APR-1994, Computer Based Learning Unit, University of Leeds.
#

$USER = "/usr/cblelca/nikos";
$LATEX2HTML = "$USER/bin/www94.script/latex2html";
$DEBUG = 0;
$OUT_DIR = "$USER/WWW/tmp/examples";
$EXAMPLES_DIR = "$USER/rep/papers/www94/examples";
$INIT = "$EXAMPLES_DIR/latex2html-init";
$LOG = "$OUT_DIR/LOG";

# This is for debugging only...
$PRINTENV = '/usr/ucb/printenv';
$| = 1;

require("$USER/WWW/cgi-bin/getformargs.pl");

&debug if $DEBUG;

&convert;
#
# FORM FIELDS:
#
# t - title
# address 
# split   
# no_navigation - navigation panel
# show_section_numbers
# ascii_mode
# info

# example
#

# GLOBAL VARIABLES
# 
# $result
# $example - 2, 3 or 5
# %in - holds the data from the form
# $command_line - holds the users choices which are passed on to latex2html

sub convert {
    unless (&busy) {
	($ENV{'QUERY_STRING'} ?
	 &GetFormArgs :
	 do {%in = ("t", "my document", "split", "0", "show_section_numbers", "0",
		    "example", "Mathematical Equations", "address", "Me",
		    "no_navigation", "1", "ascii_mode", 1, "info", "hello\n all\nsss")});
	$example = "example" . &get_example;
	&get_command_line;
	do {
	    print "Content-type: text/plain\n\n\n";
	    print "$LATEX2HTML -init_file $INIT $command_line -dir $OUT_DIR $EXAMPLES_DIR/$example.tex";} if $DEBUG;
#`/usr/bin/X11/xterm -display "cblipca:0.0"`;
	&redirect_output;
	system("$LATEX2HTML -init_file $INIT $command_line -dir $OUT_DIR $EXAMPLES_DIR/$example.tex");
        &output_back_to_normal;
	&log;
	$result = "http://cbl.leeds.ac.uk/nikos/tmp/examples/$example/$example.html\n";
    }
    &print_result;
}

sub get_command_line {
    local($_,$key,$val);
    if ($example eq "example5") {	# CHEATING because must start afresh 
				# if -ascii_mode is used
	$dir = "$OUT_DIR/example5";
	( $in{"ascii_mode"} ?
	 system("cp $dir/images.ascii $dir/images.pl") :
	 system("cp $dir/images.normal $dir/images.pl"));
    }
    foreach ("show_section_numbers", "no_navigation", "ascii_mode") {
	# if they are 0 blow them away otherwise leave them as options
	# with no arguments
	( $in{$_} ? $in{$_} = "" : delete($in{$_}));
    }
    foreach ("t", "address", "info") {
	$in{$_} = &truncate(&clean($in{$_}));
	delete($in{"$_"}) unless $in{"$_"};
    }
    foreach $key (keys %in) {
       	$command_line .= "-$key ". (($in{$key} ne "") ? "\'$in{$key}\' " : "");}
}

sub clean {
    local($_) = @_;
    # Remove newlines and shell metacharacters
    s/(\n|\W)/$1 if ($1 eq " ");/eg;
    $_;
}

sub truncate {
    local($_) = @_;
    local($message) = "<P><b> Sorry... The rest was thrown away to make the conversion faster.</b>";
    s/^(.{0,1000})(.{1001,})/$1 $message/;
    $_;
}
sub get_example {
    local($_);
    $_ = $in{'example'};
    delete $in{'example'};	# Blow it away
    if (/Structure/) {2}
    elsif (/Cross/)  {3}
    elsif (/Mathematical/) {5};
}

sub busy {
    local(@count, $count);
    @count = grep(/perl/, `ps -axur`);
    $count = @count; # Get number of perl processes running
    ( ($count > 1) ?
     $result = "Someone else has beaten you to it!\n" .
     "Please try again later in 30-60 seconds." :	# This will return true (ie busy)
     0);			# All is OK - Continue  
    }

sub print_result {
    if ($result =~ /nikos/) {
	print "Location: $result\n\n\n"}
    else {
	print "Content-type: text/plain\n\n\n";
	print $result;
    }
}

sub print_parameters {
    local($key);
    foreach $key (keys %in) {
	print "$key -- $in{$key} \n";
    }
}
    
sub redirect_output {
    open(SO, ">&STDOUT");
    open(SE, ">&STDERR");

    open(STDOUT, ">/tmp/foo$$");
    open(STDERR,">&STDOUT");

    select(STDERR); $| = 1;
    select(STDOUT); $| = 1;
}

sub output_back_to_normal {
    close(STDOUT);
    close(STDERR);
    open(STDOUT, ">&SO");
    open(STDERR, ">&SE");
}

sub log {
    open(OUTPUT, ">>$LOG");
    print OUTPUT join("\t:\t", $ENV{'REMOTE_HOST'}, $ENV{'REMOTE_ADDR'}, `date`)
	if $ENV{'QUERY_STRING'};
    close OUTPUT;
}

sub debug {
    print "Content-type: text/plain\n\n\n";
    $_ = `$PRINTENV`;
    s/ /<P>/g;
    print;
};