#!/usr/bin/perl
#   breaker.pl 1.6 2006-01-20 14:13:55-05 davidsen Exp

# breaker.pl - break a list of num/string values to max size chunks

$RevNum = '1.6';
$RevDate = '2006-01-20 14:13:55-05';

sub Usage;
sub by_size();

use Getopt::Std;
getopts("vdn:r:f:P:G") || Usage;
Usage unless defined $opt_n;
$MaxSize = $opt_n;
$Prefix = ( $opt_P ? $opt_P : "bklist." );
$Graft = $opt_G+0;

while (<>) {
	next unless m/^\s*(\d+)\s+(.+)$/;
	$item_size = $1 + $opt_f;
	$item_size = $opt_r * int(($item_size + $opt_r - 1) / $opt_r) if $opt_r;
	# validate the size
	if ($item_size > $MaxSize) {
		printf "Item too big, %6d %s\n", $item_size, $2;
		next;
	}
	*WV = \$vals[$n++];
	$WV->{count} = $item_size;
	$WV->{text} = $2;
	$total += $item_size;
}

# get the target number of media
$Nmedia = int(($total + $MaxSize - 1) / $MaxSize);
print "Nmedia: $Nmedia, total: $total, n: $n\n" if $opt_d;
$Target = $total / $Nmedia;

if ($opt_v) {
	printf "Total %d items, on %d media, target size %d (%.2f%%)\n",
		$total, $Nmedia, $Target, 100 * $Target / $MaxSize;
}

# sort by value for selection
@vals = sort by_size @vals;

# start building files
for ($file = 1; $file <= $Nmedia; ++$file) {
	$fname = sprintf("%s%03d", $Prefix, $file);
	open(OF, ">$fname") || die "Create $fname";
	$Ftotal = $FileCount = $n = 0;
	@putfiles = ();
	while ($n <= $#vals && $Ftotal < $Target) {
		if ($ItemSize = $vals[$n]->{count}) {
			$TrialSize = $Ftotal + $ItemSize;
			if ($TrialSize <= $MaxSize) {
				$Ftotal = $TrialSize;
				$vals[$n]->{count} = 0;
				++$FileCount;
				push(@putfiles, $vals[$n]->{text});
			}
		}
		++$n;
	}
	# sort and output
	foreach $file (sort @putfiles) {
		if ($Graft) {
			print OF "$file=$file\n";
		} else {
			print OF "$file\n";
		}
	}

	close OF;
	print "  File $fname built size $Ftotal with $FileCount items\n" if $opt_v;
}

exit 0;

#Usage - how to use this

sub Usage
{
	print "breaker - break lists by size\n"
	. "\n"
	. "Usage:\n"
	. "  breaker [ options ] [ file1 [ file2 [ file3 ... ] ] ]\n"
	. "\n"
	. "Options\n"
	. " -nNN      max size per media is NN\n"
	. "           THIS IS ACTUALLY REQUIRED, NOT OPTIONAL\n"
	. " -rNN      round up sizes to multiples on NN\n"
	. " -fNN      add fixed value to each item size\n"
	. " -Pstr     prefix the file number with \"str\" (def. \"bklist.\")\n"
	. " -G        format output as \"graft points\" for mkisofs. Each name appears\n"
	. "           as \"name=name\" in the output file.\n"
	. "\n"
	. " -v        verbose output while running\n"
	. " -d        debug output (varies with version)\n"
	. "\n";

	print "\nThis is v$RevNum ($RevDate)\n";

	exit 1;
}

sub by_size()
{
	$b->{count} <=> $a->{count} || $a->{text} cmp $b->{text};
}