#!/usr/bin/perl -w
#
# $Id: throttleimg,v 1.4 1998/09/14 16:15:01 don Exp $

use Image::Magick;
use Getopt::Long;

GetOptions( "help|h|?!" => \$help,
	    "quiet|q!" => \$quiet,
	    "time|t=f" => \$time,
	    "steps|s=i" => \$steps,
	    "same-size!" => \$same_size,
	    "same-quality!" => \$same_quality,
	    "same-colors!" => \$same_colors,
            "undo|u" => \$undo,
	    );

usage() if $help || !@ARGV;
do_undo() if $undo;

if (!$time) {
    print STDERR "--time option wasn't specified, assuming 5.0 seconds.\n";
    $time = 5.0;
} elsif ($time < 0) {
    print STDERR "--time option must be a positive float.\n";
    exit 1;
}
if (!$steps) {
    print STDERR "--steps option wasn't specified, assuming 3 steps.\n";
    $steps = 3;
} elsif ($steps < 1 || $steps > 35 || ($steps != int($steps))) {
    print STDERR "--steps option must be an integer between 1 and 35.\n";
    exit 1;
}

my $count = 0;
foreach my $file (@ARGV) {
    if (-d $file) {
	print STDERR "Skipping $file, it's already a directory.\n";
        next;
    } elsif ($file !~ /\.(?:gif|jpg)$/) {
	print STDERR "Skipping $file, doesn't appear to be a GIF or JPEG.\n";
	next;
    }

    print "Processing $file...\n" unless $quiet;
    
    mkdir "$file.dir", 0775 or die $!;
    rename $file, "$file.dir/Z-$file" or die $!;
    rename "$file.dir", $file or die $!;

    print "Creating control file for $time seconds.\n" unless $quiet;
    open (CONF, "> $file/.throttle") or die $!;
    flock (CONF, 2);
    print CONF "$time\n";
    close CONF;

    my $des = "0";
    for my $i (0 .. $steps - 1) {
	my $percent = $i / $steps;
	
	my $image = new Image::Magick;
	$image->Read("$file/Z-$file");
	my ($width, $height) = $image->Get("width", "height");
	
	my @changes = ();
	if (!$same_size) {
	    my $new_width = $width * (.25 + .75 * $percent);
	    my $new_height = $height * (.25 + .75 * $percent);
	    $image->Scale(width => $new_width, height => $new_height);
	    push(@changes, "size=${new_width}x${new_height}");
	}
	if (!$same_quality && ($image->Get("magick") eq "JPG")) {
	    my $quality = 10 + 90 * $percent;
	    $image->Set(quality => $quality);
	    push(@changes, "quality=${quality}%");
	}
	if (!$same_colors && ($image->Get("magick") eq "GIF")) {
            my $colors = 10 + 245 * $percent;
            $image->Quantize(colors => $colors, colorspace => "RGB",
                             dither => "true");
            push(@changes, "colors=$colors");

	}
	$image->Write("$file/" . ++$des . "-$file");
	print "Wrote $des-$file, ", (-s "$file/$des-$file"), " bytes: ",
	      join(", ", @changes), "\n" unless $quiet;
    }
    print "Original is now Z-$file, ", (-s "$file/Z-$file"),
          " bytes\n" unless $quiet;
    $count++;
}

print "Done.  Modified $count file", $count == 1 ? "":"s", ".\n" unless $quiet;

sub do_undo {
    foreach my $file (@ARGV) {
	$file =~ s|/$||;
	if (!(-d $file)) {
	    print STDERR "Skipping $file, it isn't directory.\n";
	    next;
	} elsif (!(-e "$file/.throttle")) {
	    print STDERR "Skipping $file, no .throttle file found.\n";
	    next;
	} elsif ($file !~ /\.(?:gif|jpg)$/) {
	    print STDERR "Skipping $file, doesn't appear to be a ".
                         "GIF or JPEG.\n";
	    next;
	} elsif (!(-e "$file/Z-$file")) {
	    print STDERR "Skipping $file, no original (\"Z-$file\") found.\n";
	    next;
	}

	print "Processing $file...\n" unless $quiet;
    
	rename "$file", "$file.dir" or die $!;
	rename "$file.dir/Z-$file", "$file" or die $!;

	opendir (SF, "$file.dir") || die $!;
	foreach (readdir(SF)) {
	    if (/^[0-9A-Y]-$file$/ || /^\.throttle/) {
		print "Removing $_...\n" unless $quiet;
		unlink "$file.dir/$_";
	    }
	}
        closedir SF;

	rmdir "$file.dir" or
	    print STDERR "The directory contained non-throttle files... ".
		"moved them to $file.dir/\n";
	
	print "Unthrottled $file from $file/Z-$file.\n" unless $quiet;
    }
    print STDERR "Done.\n" unless $quiet;
    exit;
}

sub usage {
    print STDERR <<"EndOfUsage";
Usage:  throttleimg [options] file1 ...

  --help           this screen
  --quiet          don't output anything to STDOUT
  --time=2.3       time (in seconds) that the image should take to load
  --steps=4        number of different images to create
  --same-size      don't change the image resolution
  --same-colors    don't change the number of colors (default for JPEGs)  
  --same-quality   don't change the image quality (default for GIFs)
  --undo           does the opposite: makes it a normal image
EndOfUsage
    exit 1;
}

__END__

=head1 NAME

throttleimg - Script to automatically split images into multiple sizes

=head1 SYNOPSIS

throttleimg [options] file1 ...

=head1 DESCRIPTION

throttleimg is a script distributed with Apache::Throttle.  It can be used
to automatically create a set of different size images from one large image
and store them in a format that Apache::Throttle will understand.

The file (or files) you specify will be replaced with a directory of the
same name. The original file will be saved in this directory as
"Z-<original name>".  throttleimg will then create a set of images (the
number of images can be set with the --steps option and defaults to 3)
that look like the original image but have a lower quality.

Theoretically, this script can be used to automatically convert all of your
existing images to be controlled by Apache::Throttle.  You might try a
command like:

    find /home/httpd -name '*.gif' -o -name '*.jpg' | \
        xargs throttleimg --time=5 --steps=3

=head1 OPTIONS

=over 4

=item --help, -h

Shows usage information.

=item --quiet, -q

This option tells throttleimg not to output any status messages to
STDOUT.  Only warnings and errors are printed to STDERR.

=item --time=<seconds>, -t=<seconds>

This is the time in seconds that the image should take to load.  It is
used to determine the speed required to download each image.  This can
be a floating point number.

=item --steps=<images>, -s=<seconds>

This option tells throttleimg how many different images to make.

=item --same-size

This option tells throttleimg not to change the size of the images
created.  You probably want to use this if you're using these images
inline in a HTML page and don't plan to use WIDTH and HEIGHT arguments
in the <IMG> tag.

=item --same-colors

This option tells throttleimg not to change the number of colors in
the images created.  It is the default value for JPEGs.

=item --same-quality

This option tells throttleimg not to change the quality of the images
created.  It is the default value for GIFs.

=item --undo, -u

This option causes throttleimg to do the opposite of what it normally
does.  Instead of turning an image into a directory of different images,
it removes all of the images created by a previous call to throttleimg
and replaces the directory with the original image.

=back

=head1 AUTHOR

Don Schwarz <dons@xnet.com>

=head1 SEE ALSO

L<Apache::Throttle>, L<mod_perl>

=head1 COPYRIGHT

Copyright (c) 1998 Don Schwarz. All rights reserved. This program is free
software; you can redistribute it and/or modify it under the same terms
as Perl itself.

=cut