package CPAN::Version;

use strict;
use vars qw($VERSION);
$VERSION = "5.5001";

# CPAN::Version::vcmp courtesy Jost Krieger
sub vcmp {
my($self,$l,$r) = @_;
local($^W) = 0;
CPAN->debug("l[$l] r[$r]") if $CPAN::DEBUG;

return 0 if $l eq $r; # short circuit for quicker success

for ($l,$r) {
s/_//g;
}
CPAN->debug("l[$l] r[$r]") if $CPAN::DEBUG;
for ($l,$r) {
next unless tr/.// > 1 || /^v/;
s/^v?/v/;
1 while s/\.0+(\d)/.$1/; # remove leading zeroes per group
}
CPAN->debug("l[$l] r[$r]") if $CPAN::DEBUG;
if ($l=~/^v/ <=> $r=~/^v/) {
for ($l,$r) {
next if /^v/;
$_ = $self->float2vv($_);
}
}
CPAN->debug("l[$l] r[$r]") if $CPAN::DEBUG;
my $lvstring = "v0";
my $rvstring = "v0";
if ($] >= 5.006
&& $l =~ /^v/
&& $r =~ /^v/) {
$lvstring = $self->vstring($l);
$rvstring = $self->vstring($r);
CPAN->debug(sprintf "lv[%vd] rv[%vd]", $lvstring, $rvstring) if $CPAN::DEBUG;
}

return (
($l ne "undef") <=> ($r ne "undef")
||
$lvstring cmp $rvstring
||
$l <=> $r
||
$l cmp $r
);
}

sub vgt {
my($self,$l,$r) = @_;
$self->vcmp($l,$r) > 0;
}

sub vlt {
my($self,$l,$r) = @_;
$self->vcmp($l,$r) < 0;
}

sub vge {
my($self,$l,$r) = @_;
$self->vcmp($l,$r) >= 0;
}

sub vle {
my($self,$l,$r) = @_;
$self->vcmp($l,$r) <= 0;
}

sub vstring {
my($self,$n) = @_;
$n =~ s/^v// or die "CPAN::Version::vstring() called with invalid arg [$n]";
pack "U*", split /\./, $n;
}

# vv => visible vstring
sub float2vv {
my($self,$n) = @_;
my($rev) = int($n);
$rev ||= 0;
my($mantissa) = $n =~ /\.(\d{1,12})/; # limit to 12 digits to limit
# architecture influence
$mantissa ||= 0;
$mantissa .= "0" while length($mantissa)%3;
my $ret = "v" . $rev;
while ($mantissa) {
$mantissa =~ s/(\d{1,3})// or
die "Panic: length>0 but not a digit? mantissa[$mantissa]";
$ret .= ".".int($1);
}
# warn "n[$n]ret[$ret]";
$ret =~ s/(\.0)+/.0/; # v1.0.0 => v1.0
$ret;
}

sub readable {
my($self,$n) = @_;
$n =~ /^([\w\-\+\.]+)/;

return $1 if defined $1 && length($1)>0;
# if the first user reaches version v43, he will be treated as "+".
# We'll have to decide about a new rule here then, depending on what
# will be the prevailing versioning behavior then.

if ($] < 5.006) { # or whenever v-strings were introduced
# we get them wrong anyway, whatever we do, because 5.005 will
# have already interpreted 0.2.4 to be "0.24". So even if he
# indexer sends us something like "v0.2.4" we compare wrongly.

# And if they say v1.2, then the old perl takes it as "v12"

if (defined $CPAN::Frontend) {
$CPAN::Frontend->mywarn("Suspicious version string seen [$n]\n");
} else {
warn("Suspicious version string seen [$n]\n");
}
return $n;
}
my $better = sprintf "v%vd", $n;
CPAN->debug("n[$n] better[$better]") if $CPAN::DEBUG;
return $better;
}

1;

__END__

=head1 NAME

CPAN::Version - utility functions to compare CPAN versions

=head1 SYNOPSIS

use CPAN::Version;

CPAN::Version->vgt("1.1","1.1.1"); # 1 bc. 1.1 > 1.001001

CPAN::Version->vlt("1.1","1.1"); # 0 bc. 1.1 not < 1.1

CPAN::Version->vcmp("1.1","1.1.1"); # 1 bc. first is larger

CPAN::Version->vcmp("1.1.1","1.1"); # -1 bc. first is smaller

CPAN::Version->readable(v1.2.3); # "v1.2.3"

CPAN::Version->vstring("v1.2.3"); # v1.2.3

CPAN::Version->float2vv(1.002003); # "v1.2.3"

=head1 DESCRIPTION

This module mediates between some version that perl sees in a package
and the version that is published by the CPAN indexer.

It's only written as a helper module for both CPAN.pm and CPANPLUS.pm.

As it stands it predates version.pm but has the same goal: make
version strings visible and comparable.

=head1 LICENSE

This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

=cut

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