#!/usr/bin/perl -w

# Written By Martin Owens, Copyright 2007; GPLv3

use strict;

if($ARGV[0] eq '--help') {
	print "Disc Media File Calculator - This program will calculate how files can best fit onto a CD ROM or other disc media.

Uusage: $0 DiscSizeInMB Directories ...";
	exit 0;
} elsif($ARGV[0] eq '--version') {
	print "\nDisc Media File Calculator - Version 1.04 (2007-09-12)\n\n";
	exit 0;
}

if(@ARGV > 3 or $ARGV[0] !~ /^\d+$/) {
	die "Incorrect use:

  $0 DiscSizeInMB ISO-Location [Directories...]

  Example:

  $0 680 /tmp/iso-disc ~/my-files/ ~/my-music/ ~/.*

";
}

my $disksize = shift(@ARGV) * 1024 * 1024;
my $isoroot  = shift(@ARGV);
my $dirs = @ARGV ? '"'.join('" "', @ARGV).'"' : '.';

open( USE, "du -ab $dirs|" );

#print "Setting it $ARGV[0]\n";

my @discs;
my @sizes;
my @files;

print "\nGenerating list of files...";

while ( <USE> ) {
	if($_ =~ /(\d+)\s+(.+)/) {
		if(-f $2) {
			print ".";
			push @sizes, $1;
			push @files, $2;
		}
	}
}

close( USE );

print "\nSorting files...";

my @sfiles = @files[ sort { $sizes[$b] <=> $sizes[$a] } 0 .. $#sizes ];
my @ssizes = sort { $b <=> $a } @sizes;

FILE: for(my $i=0;$i<=$#sfiles;$i++) {
	my $file = $sfiles[$i];
	my $size = $ssizes[$i];
	foreach my $disk (@discs) {
		if($disk->{'space'} > $size) {
			push @{$disk->{'files'}}, $file;
			$disk->{'space'} -= $size;
			$disk->{'count'}++;
			next FILE
		}
	}
	# We need a new disk
	if($disksize > $size) {
		push @discs, { space => $disksize - $size, count => 1, files => [ $file ] };
	} else {
		warn "Error unable to fit $file onto any Disc, discs are too small.\n";
	}
}

print "\nCreating iso disc images...\n";

my $index = 0;
foreach my $disc (@discs) {
	$index++;
	my $isofile = "$isoroot-$index.iso";
	print "Creating ISO file '$isofile'\n";
		open(ISOFILE, "|mkisofs -J -input-charset iso8859-1 -graft-points -quiet -o $isofile -A BACKUP -path-list -");
			foreach my $file (@{$disc->{'files'}}) {
				$file =~ /^(.*?)[^\/]+$/;
				my $dir = $1;
				$dir =~ s/^\.?\///;
				#print "  - $dir=$file\n";
				if($dir) {
					print ISOFILE "$dir=$file\n";
				} else {
					print ISOFILE "$file\n";
				}
			}
			print "Writing ISO file to disk\n"; 
		close(ISOFILE);
	print "\n";
}

exit 0;