<?php
// $Id: ip2country.module,v 1.12 2010/10/17 17:02:07 tr Exp $

/**
 * @file
 * Determination of user's Country based on IP
 *
 * This module uses the IP Address that a user is connected from to deduce
 * the Country where the user is located.  This method is not foolproof,
 * because a user may connect through an anonymizing proxy, or may be in
 * an unusual case, such as getting service from a neighboring country,
 * or using an IP block leased from a company in another country.
 * Additionaly, users accessing a server on a local network may be using
 * an IP that is not assigned to any country (e.g. 192.168.x.x).
 *
 * Country determination occurs upon user login.  If a country can be
 * determined from the IP address, the ISO 3166 2-character country code
 * is stored in the Drupal $user object as $user->country_iso_code_2.
 * If no country can be determined, this member is left unset.
 *
 * The database used is maintained by ARIN, the American Registry for
 * Internet Numbers (http://www.arin.net/about_us/index.html), which is
 * one of the 5 official Regional Internet Registries (RIR) responsible
 * for assigning IP addresses.  The claim is the database is 98% accurate,
 * with most of the problems coming from users in less-developed countries.
 * Regardless, there's no more-authoritive source of this information.
 *
 * @author Tim Rohaly.    <http://drupal.org/user/202830>
 * @version $Id: ip2country.module,v 1.12 2010/10/17 17:02:07 tr Exp $
 */


/** Utility functions for loading IP/Country DB from external sources */
module_load_include('inc', 'ip2country', 'ip2country');


/******************************************************************************
 * Drupal Hooks                                                               *
 ******************************************************************************/


/**
 * Implementation of hook_help().
 */
function ip2country_help($path, $arg) {
  switch ($path) {
    case 'admin/help#ip2country':
      return t('Detects Country of user based on IP address.');
      break;

    case 'admin/settings/ip2country':
      return t('Configuration settings for the ip2country module.');
      break;
  }
}


/**
 * Implementation of hook_perm().
 */
function ip2country_perm() {
  return array('administer ip2country');
}


/**
 * Implementation of hook_cron().
 *
 * Updates the IP to Country database automatically on a periodic
 * basis.  Default period is 1 week.
 */
function ip2country_cron() {
  if (variable_get('ip2country_last_update', 0) <=
      time() - variable_get('ip2country_update_interval', 604800)) {
    ip2country_update_database(variable_get('ip2country_rir', 'arin'));
    variable_set('ip2country_last_update', time());
    if (variable_get('ip2country_watchdog', 1)) {
      watchdog('ip2country', 'Database updated from @registry server.', array('@registry' => drupal_strtoupper(variable_get('ip2country_rir', 'arin'))), WATCHDOG_NOTICE);
    }
  }
}


/**
 * Implementation of hook_menu().
 *
 * Called when Drupal is building menus.  Cache parameter lets module know
 * if Drupal intends to cache menu or not - different results may be
 * returned for either case.
 *
 * @return
 *   An array with the menu path, callback, and parameters.
 */
function ip2country_menu() {
  $items = array();

  $items['admin/settings/ip2country'] = array(
    'title'            => 'IP to Country Settings',
    'description'      => 'Configure the IP/Country settings',
    'access arguments' => array('administer ip2country'),
    'page callback'    => 'drupal_get_form',
    'page arguments'   => array('ip2country_admin_settings'),
    'type'             => MENU_NORMAL_ITEM,
    'file'             => 'ip2country.admin.inc',
  );
  $items['admin/settings/ip2country/update'] = array(
    'title'            => 'Update Database',
    'access arguments' => array('administer ip2country'),
    'page callback'    => '_ip2country_update',
    'type'             => MENU_CALLBACK,
    'file'             => 'ip2country.admin.inc',
  );
  $items['admin/settings/ip2country/lookup'] = array(
    'title'            => 'Lookup IP Address in Database',
    'access arguments' => array('administer ip2country'),
    'page callback'    => '_ip2country_lookup',
    'type'             => MENU_CALLBACK,
    'file'             => 'ip2country.admin.inc',
  );

  return $items;
}


/**
 * Implementation of hook_user().
 *
 * Detects IP and determines country upon user login.
 */
function ip2country_user($op, &$edit, &$account, $category = NULL) {
  switch ($op) {
    case 'login':
      // Successful login. First determine user's country based on IP
      $ip = ip_address();
      $country_code = ip2country_get_country($ip);

      // Now check to see if this user has "administer ip2country" permission
      // and if debug mode set.  If both are TRUE, use debug information
      // instead of real information
      if (user_access('administer ip2country') &&
          variable_get('ip2country_debug', FALSE)) {
        $type = variable_get('ip2country_test_type', 0);
        if ($type == 0) {  // Debug Country entered
          $country_code = variable_get('ip2country_test_country', 'US');
        }
        else {  // Debug IP entered
          $ip = variable_get('ip2country_test_ip', $ip);
          $country_code = ip2country_get_country($ip);
        }
        drupal_set_message(t('Using DEBUG value for Country - @country', array('@country' => $country_code)));
      }

      // Finally, save country, if it has been determined
      if ($country_code) {
        // Store the ISO country code in the $user object
        user_save($account, array('country_iso_code_2' => $country_code));
      }

      break;
  }
}


/******************************************************************************
 * Module Functions                                                           *
 ******************************************************************************/


/**
 * Get the ISO 3166 2-character country Code from the IP address
 *
 * @return
 *   FALSE if the lookup failed to find a country for this IP
 */
function ip2country_get_country($ip_address) {
  $ipl = ip2long($ip_address);
  if (is_long($ip_address)) {
    $ipl = ip_address;
  }

  // Locate IP within ranges
  $sql    = "SELECT country FROM {ip2country}
             WHERE (%d >= ip_range_first AND %d <= ip_range_last) LIMIT 1";
  $result = db_result(db_query($sql, $ipl, $ipl));

  return $result;
}


/**
 * Get the total count of IP ranges in database
 */
function ip2country_get_count() {
  $sql   = "SELECT COUNT(*) FROM {ip2country}";
  $count = db_result(db_query($sql));
  return (int) $count;
}