#!/usr/bin/perl

use strict;
use warnings;

use WannaBuild; # for version compare

if (!@ARGV) {
	print STDERR "Usage: $0 Packages1 Packages2 ..\n";
	print STDERR "\n";
	print STDERR "This perl scripts reads the Packages files given on the command line and\n";
	print STDERR "outputs a Packages file which contians each package exactly once, using the\n";
	print STDERR "one with the highest version number.\n";
	print STDERR "";
	print STDERR "Since it only looks at Package: and Version:, it works with Sources files\n";
	print STDERR "as well\n";
	exit 1;
}

my %version;
my %data;

local($/) = ""; # read in paragraph mode
while (<>) {
	my( $version, $name );
	/^Package:\s*(\S+)$/mi and $name = $1;
	/^Version:\s*(\S+)$/mi and $version = $1;
	if (!defined $name or !defined $version) {
		warn "Stanza without Package or Version\n";
		next;
	}

	if ((!exists $version{$name}) or version_less($version{name},$version)) {
		$version{$name} = $version;
		$data{$name} = $_;
	}
}

foreach (values %data) {
	s/\n*$/\n\n/;# always one empty line to separate stanzas
	print;
}