#! /usr/bin/perl

use warnings;
use strict;


use IO::File;
use Getopt::Std;

my $conf = {bans           => 'bans.txt',
            bans_to_remove => 'bans_to_remove.txt',
            bans_to_keep   => 'bans_to_keep.txt',
	    minimum_age    => 1209600, # two weeks
	    max_ubans      => 4,
           };

my $options = {};
getopt('b:k:r:a:',$options);

$conf->{bans} = $options->{b} || $conf->{bans};
$conf->{bans_to_remove} = $options->{r} || $conf->{bans_to_remove};
$conf->{bans_to_keep} = $options->{k} || $conf->{bans_to_keep};
$conf->{minimum_age} = $options->{a} || $conf->{minimum_age};

my $bans_fh = new IO::File $conf->{bans}, 'r' or die "Unable to open file $conf->{bans} for reading: $!";;

my $bans_r_fh = new IO::File $conf->{bans_to_remove}, 'w' or
     die "Unable to open file $conf->{bans_to_remove} for writing: $!";

my $bans_k_fh = new IO::File $conf->{bans_to_keep}, 'w' or
     die "Unable to open file $conf->{bans_to_keep} for writing: $!";

my @bans_to_remove;

while (<$bans_fh>) {
     # pull the ban and the times.
     print {$bans_k_fh} $_ and next unless my ($channel, $banmask, $time) = 
	  $_ =~ /(\#\w+)\:\s+ban\s+([\w\d\*\@\%\!\-\_\.]+)\s+\[by\s*.*?\,\s+(\d+)\s+secs/;
     print {$bans_k_fh} $_ and next unless $time > $conf->{minimum_age};

     # Ignore bans against specific users.
     print {$bans_k_fh} $_ and next if $banmask =~ /^\%?\w/;

     # Ignore wide bans
     print {$bans_k_fh} $_ and next if $banmask =~ /\*\!.*?\@.*\*.*/;

     push @bans_to_remove, $banmask;
}


while (my @unbans = splice(@bans_to_remove,0,$conf->{max_ubans})) {
     print {$bans_r_fh} q(/mode -), q(b) x ($#unbans+1), q( ), join(' ',@unbans);
     print {$bans_r_fh} qq(\n);
}