#!/usr/bin/perl -w
#
# Written by Travis Kent Beste
# Thu Aug 16 10:37:10 CDT 2007
#
# $Id: create_thumbnail.pl,v 1.3 2007/08/21 15:45:13 travis Exp $
# $Source: /cvs_repository/thumbnails/create_thumbnail.pl,v $

use strict;
use Data::Dumper;
use Image::Magick;
use Getopt::Std;
$|++;


my %opts;
getopts('f:w:dhi', \%opts);

#----------------------------------------#
# main
#----------------------------------------#
my $filename = $opts{'f'} || '';
my $width    = $opts{'w'} || 120;
my $debug    = $opts{'d'} || 0;
my $info     = $opts{'i'} || 0;
my $help     = $opts{'h'} || 0;

if ($help) {
	usage();
}

if ($info) {
	if (! -e $filename) {
		usage();
	}


	my $image         = Image::Magick->new(magick=>'JPEG');
	my $x             = $image->Read($filename);
	printf "\twidth         : %d\n", $image->Get('width');
	printf "\theight        : %d\n", $image->Get('height');
	exit;
}

# thumbnail width we're going for
my $projected_width = $width;  # the width that we're shooting for
my $projected_error = 20;      # the margin of error to check for

print "projected_width : $projected_width\n";
print "projected_error : $projected_error\n";

if (! -e $filename) {

	opendir(DIR, './');
	my @files = sort grep(/jpg$/i, readdir(DIR));
	closedir(DIR);

	foreach my $filename (@files) {
		if ( ($filename !~ /\.small\./) && ($filename !~ /\.thumb\./) ) {
			process_file($filename, $debug);
		}
	}

} else {
	process_file($filename, $debug);
}


exit(0);

#----------------------------------------#
# subroutines
#----------------------------------------#
sub usage {
	print "Usage: $0\n";
	print "\t-d : debug\n";
	print "\t-w : width of final image requested\n";
	print "\t-f : file, defaults to reading directory for files ending with '.jpg'\n";
	print "\t-i : info, you'll need to supply -f\n";
	print "\t-h : help, this menu\n";
	exit(0);
}

sub get_divisor {
	my $width   = shift;
	my $divisor = 0;
	my $prev    = $width;
	my $issue   = 0;

	for(my $i = 1; $i < 20; $i++) {
		if (
				($width / $i) < ($projected_width + $projected_error) &&
				($width / $i) > ($projected_width - $projected_error)
			) {
			return $i;
		}

		if ( ($prev - ($width/$i)) > 200) {
			$issue = 1;
		}
		$prev = $width/$i;
		if ($debug) {
			printf "%3d - %4d  %4d  %4d\n", $i, $projected_width + $projected_error, ($width/$i), $projected_width - $projected_error;
		}
	}

	if ($issue == 1) {
		return get_float_divisor($width);
	}
}

sub get_float_divisor {
	my $width   = shift;
	my $divisor = 0;
	my $prev    = $width;
	my $issue   = 0;

	for(my $i = 1; $i < 5; $i++) {
		for(my $j = 0; $j < 10; $j++) {
			my $divisor = sprintf("%d.%d", $i, $j);
			print "$divisor\n";
			if (
					($width / $divisor) < ($projected_width + $projected_error) &&
					($width / $divisor) > ($projected_width - $projected_error)
				) {
				return $divisor;
			}
			if ($debug) {
				printf "%3d - %4d  %4d  %4d\n", $i, $projected_width + $projected_error, $width/$divisor, $projected_width - $projected_error;
			}
		}
	}
}

sub process_file {
	my $filename  = shift;
	my $debug     = shift;
	my $thumbnail = $filename;

	print "inspecting $filename...\n";

	$thumbnail =~ s/\.jpg//i;
	$thumbnail .= '.small.jpg';
	if (! -e $thumbnail) {
		print "processing $filename...\n";
		my $image         = Image::Magick->new(magick=>'JPEG');
		my $x             = $image->Read($filename);
		printf "\twidth         : %d\n", $image->Get('width');
		printf "\theight        : %d\n", $image->Get('height');
		my $divisor       = get_divisor($image->Get('width'));
		printf "\tdivisor       : %5.2f\n", $divisor;
		my $scaled_width  = sprintf("%d", $image->Get('width') / $divisor);
		printf "\tscaled_width  : $scaled_width\n";
		my $scaled_height = sprintf("%d", $image->Get('height') / $divisor);
		printf "\tscaled_height : $scaled_height\n";

		# scale the image
		$x = $image->Scale(width=>$scaled_width, height=> $scaled_height);
		
		# write the thumbnail
		$x = $image->Write($thumbnail);
	} else {
		print "thumbnail exists...\n";
	}

	# move the uppercase to lowercase for '.jpg'
	if ($filename =~ /JPG$/) {
		my $new = $filename;
		my $old = $filename;
		$new =~ s/\.JPG/\.jpg/;
		printf "\tmv $old $new";
		system("mv $old $new");
	}
	print "Done.\n";
}