# Copyright (C) 1998,2002 Julian Gilbey <jdg@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or (at
# your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.

# The functions in this Perl module are versort, upstream_versort and
# deb_versort.  They each take as input an array of elements of the form
# [version, data, ...] and sort them into decreasing order according to dpkg's
# understanding of version sorting.  The output is a sorted array.  In
# upstream_versort, "version" is assumed to be an upstream version number only,
# whereas in deb_versort, "version" is assumed to be a Debian version number,
# possibly including an epoch and/or a Debian revision. versort is available
# for compatibility reasons. It compares versions as Debian versions
# (i.e. 1-2-4 < 1-3) but disables checks for wellformed versions.
#
# The returned array has the greatest version as the 0th array element.

package Devscripts::Versort;
use Dpkg::Version;

sub versort (@) {
    return _versort(0, sub { return shift->[0] }, @_);
}

sub deb_versort (@) {
    return _versort(1, sub { return shift->[0] }, @_);
}

sub upstream_versort (@) {
    return _versort(0, sub { return "1:" . shift->[0] . "-0" }, @_);
}

sub _versort ($@) {
    my ($check, $getversion, @namever_pairs) = @_;

    foreach my $pair (@namever_pairs) {
        unshift(@$pair,
            Dpkg::Version->new(&$getversion($pair), check => $check));
    }

    my @sorted = sort { $b->[0] <=> $a->[0] } @namever_pairs;

    foreach my $pair (@sorted) {
        shift @$pair;
    }

    return @sorted;
}

1;