#!/usr/bin/perl

package NEWEST;

use Getopt::Long;
use File::Basename;

my $src_dir;
my $basename;
my $type = "tar.gz";
my $versions;
my $help;
my %KEEPER;


GetOptions(
           "src_dir=s" => \$src_dir,
           "basename=s" => \$basename,
	   "type=s" => \$type,
	   "versions!" => \$versions,
           "help!" => \$help
           );

if (!defined $src_dir || !defined $basename) {
  $help = 1;
}

if ($help) {
  &help();
  exit;
}


&extract_version(\$src_dir, \$basename, \$type, \%KEEPER);
&print_max(\%KEEPER, \$type, \$versions, &find_max(\%KEEPER));



sub extract_version {
  my $src_dir = shift;
  my $basename = shift;
  my $type = shift;
  my $KEEPER = shift;

  while (glob("$${src_dir}/$${basename}*")) {
    my $base = basename("$_",".$${type}");
    my @ver = split /-/, $base;
    my @nums = split /\./, $ver[$#ver];

    my $new;
    for (my $i=0; $i<$#nums+1; $i++) {
      $new =~ s/^([0-9]*)([a-zA-Z]*)$/$1/;
      $new .= 10000+$nums[$i];
      $new .= $2;
    }
    $KEEPER->{"$new"} = [$base,$ver[$#ver]];
  }

  return;
}



sub find_max {
  my $KEEPER = shift;

  return reverse sort (keys %$KEEPER);
}



sub print_max {
  my $KEEPER = shift;
  my $type = shift;
  my $versions = shift;
  my $max_key = shift;

  if ($${versions}) {
    print "$KEEPER->{$max_key}->[1]\n";
  }
  else {
    print "$KEEPER->{$max_key}->[0]" . ".$${type}\n";
  }

  return;
}



sub help {

  print qq("newest" finds the tarball in a given directory with the newest version number
and returns it's filename. "newest" is meant to be embedded in UNIX shell
scripts.

Usage:

newest  -(src_dir | s)      /path/to/dir/with/tarballs
        -(basename | b)     BaseName (ex. BaseName-2.10.tar.gz)
        -(type | t)         Type of file (default: tar.gz)
        -(versions | v)     Print only version information
	-(help | h)         Prints usage help

Ex: \$ /opt/bin/newest -s /opt/incoming/pm_modules -b Data-Dumper
    Data-Dumper-2.101.tar.gz

Both arguments, '-s' and '-b' are required; '-t' and '-v' are optional.

);

  return;
}