# Selima Website Content Management System
# GeoIP.pm: The GeoIP-related subroutines.

#  Copyright (c) 2004-2018 imacat.
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

# Author: imacat <imacat@mail.imacat.idv.tw>
# First written: 2004-10-16

package Selima::GeoIP;
use 5.008;
use strict;
use warnings;
use base qw(Exporter);
use vars qw(@EXPORT @EXPORT_OK);
BEGIN {
@EXPORT = qw(country_lookup);
@EXPORT_OK = @EXPORT;
# Prototype declaration
sub country_lookup(;$);
}

use Geo::IP qw(GEOIP_MEMORY_CACHE);
use Net::CIDR::Lite qw();

BEGIN {
if (exists $ENV{"MOD_PERL_API_VERSION"} && $ENV{"MOD_PERL_API_VERSION"} >= 2) {
    require Apache2::Connection;
}
}

use Selima::DataVars qw(:env);

use vars qw($PRIVATE_NETWORKS);
$PRIVATE_NETWORKS = Net::CIDR::Lite->new(
    qw(10.0.0.0/8 172.16.0.0/12 192.168.0.0/16));

use constant CT_PRIVATE => "AA";
use constant CT_UNKNOWN => "ZZ";

# country_lookup: Look-up country from IP
sub country_lookup(;$) {
    local ($_, %_);
    my ($GI, $ip, $ct);
    $ip = $_[0];
    # Default to look up the client
    $ip = $IS_MODPERL? ($IS_MP2?
            Apache2::RequestUtil->request->connection->remote_ip:
            Apache->request->connection->remote_ip):
            $ENV{"REMOTE_ADDR"}
        if !defined $ip;
    # Start a new GeoIP handler.  It rarely needs to be cached
    $GI = Geo::IP->new(GEOIP_MEMORY_CACHE);
    # Look up in the GeoIP database
    return uc $_ if defined($_ = $GI->country_code_by_addr($ip));
    # Look up private IP
    return CT_PRIVATE if $PRIVATE_NETWORKS->find($ip);
    # Not known
    return CT_UNKNOWN;
}

return 1;