package MT::Plugin::BanNonJapaneseTBPing;
# mt-ban-nonja-tb.pl
# - Deny or moderate Non Japanese trackback ping using MT3 CommentFilter API
#
# Author:  Yasuhiro Horiuchi <horiuchi at vcube.com>
# License: same as Perl
#

use strict;
our $VERSION = "0.2";

# charcter repetation
our $CharRep = 3;

# number of match
our $NofMatch = 1;

use MT;
use MT::Plugin;
use MT::I18N;

my $plugin = MT::Plugin->new({
    name => "BanNonJapaneseTBPing v$VERSION",
    description => "Deny Non japanese trackback ping",
});

MT->add_plugin($plugin);
MT->add_callback('TBPingFilter', 2, $plugin, \&handler);

sub handler {
    my($eh, $app, $ping) = @_;
    my $charset = MT::ConfigMgr->instance->PublishCharset;
    my $excerpt = MT::I18N::encode_text($ping->excerpt, $charset, 'euc');
    my @match = $excerpt =~ /((?:\xA4[\xA1-\xF3]|\xA1[\xAB\xAC\xB5\xB6])|(?:\xA5[\xA1-\xF6]|\xA1[\xA6\xBC\xB3\xB4])){$CharRep,}/g;
    if ( @match < $NofMatch ) {
        my $remote_ip = $ENV{'HTTP_X_FORWARDED_FOR'} || $app->remote_ip;
        $app->log("Non Japanese trackback ping from $remote_ip");
        return 0;
    }
    return 1;
}

1;