<?php
// $Id: browscap.module,v 1.6.2.3.2.11 2009/09/30 17:16:40 greggles Exp $

/**
 * @file
 * Replacement for PHP's get_browser() function
 */

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

/**
 * Implementation of hook_menu().
 *
 * @return array
 */
function browscap_menu() {
  // LOG PAGES
  $items['admin/reports/browscap'] = array(
    'title' => t('Browscap'),
    'description' => t('Browser-specific site statistics.'),
    'page callback' => 'browscap_top_useragents',
    'page arguments' => array('all'),
    'access arguments' => array('access administration pages'),
    'weight' => 5);
  $items['admin/reports/browscap/useragents'] = array(
    'title' => t('All user agents'),
    'access arguments' => array('access administration pages'),
    'weight' => 1,
    'type' => MENU_DEFAULT_LOCAL_TASK
  );
  $items['admin/reports/browscap/browsers'] = array(
    'title' => t('Browsers'),
    'page callback' => 'browscap_top_useragents',
    'page arguments' => array('browsers'),
    'access arguments' => array('access administration pages'),
    'weight' => 2,
    'type' => MENU_LOCAL_TASK
  );
  $items['admin/reports/browscap/crawlers'] = array(
    'title' => t('Crawlers'),
    'page callback' => 'browscap_top_useragents',
    'page arguments' => array('crawlers'),
    'access arguments' => array('access administration pages'),
    'weight' => 3,
    'type' => MENU_LOCAL_TASK
  );

  // SETTINGS PAGE
  $items['admin/settings/browscap'] = array(
    'title' => t('Browscap'),
    'description' => t('Enable browscap site statistics.'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('browscap_settings'),
    'access arguments' => array('administer site configuration'),
  );

  $items['admin/settings/browscap/refresh'] = array(
    'title' => t('Browscap Refresh'),
    'page callback' => 'browscap_refresh',
    'access arguments' => array('administer site configuration'),
    'type' => MENU_CALLBACK,
  );
  $items['admin/reports/browscap/useragent/%browscap_useragent'] = array(
    'title' => 'Useragent details',
    'page callback' => 'browscap_useragent_properties',
    'page arguments' => array(4),
    'access arguments' => array('access administration pages'),
    'weight' => 5,
    'type' => MENU_LOCAL_TASK
  );
  return $items;
}

/**
 * Implementation of hook_exit().
 *
 * Keep tabs on browsers that visit
 */
function browscap_exit() {
  // If monitoring is enabled, record the browser
  if (variable_get('browscap_monitor', FALSE)) {
    if ($browser = browscap_get_browser()) {
      $browserstring = substr(trim($browser['parent']), 0, 255);
      if ($browserstring == '' or $browserstring == 'Default Browser') {
        $browserstring = trim($_SERVER['HTTP_USER_AGENT']);
      }
      db_query("UPDATE {browscap_statistics} SET counter = counter + 1, is_crawler=%d ".
        "WHERE parent='%s'", $browser['crawler'], $browserstring);
      // If we affected 0 rows, this is the first time we've seen this browser
      if (!db_affected_rows()) {
        // We must create a new row to store counters for the new browser.
        db_query('INSERT INTO {browscap_statistics} (parent,counter,is_crawler) '.
          "VALUES('%s', 1, %d)", $browserstring, $browser['crawler']);
      }
    }
  }
}

/**
 * Implementation of hook_cron().
 */
function browscap_cron() {
  // Has it been a week since the last (attempt to) import?
  $last_imported = variable_get('browscap_imported', 0);
  if (($last_imported + 60*60*24*7) < time()) {
    _browscap_import();
    variable_set('browscap_imported', time());
  }
}

/**
 * ******************** Menu Callbacks ************************
 */

/**
 * Callback for settings form.
 * Turn monitoring on or off and refresh the reference data.
 *
 * @return array
 */
function browscap_settings() {
  $form['browscap_data_status'] = array(
    '#value' => t('<p>Browscap data current as of %fileversion. [<a href="!refresh">Refresh now</a>]</p>',
                   array(
                     '%fileversion' => variable_get('browscap_version', t('Never fetched')),
                     '!refresh' => url('admin/settings/browscap/refresh'),
                   )),
  );

  $form['browscap_monitor'] = array(
    '#type' => 'checkbox',
    '#title' => t('Monitor browsers'),
    '#default_value' => variable_get('browscap_monitor', FALSE),
    '#description' => t('Monitor all user agents visiting the site. View the reports in the <a href="!reports">Browscap reports</a> area.',
                        array(
                          '!reports' => url('admin/reports/browscap'),
                        )),
  );
  return system_settings_form($form);
}

/**
 * Simple page callback to manually refresh the data.
 *
 */
function browscap_refresh() {
  _browscap_import(FALSE);
  drupal_goto('admin/settings/browscap');
}

/**
 * Menu callback; presents the user agents monitoring page.
 *
 * @param $view
 *   - "browsers": Only display "real" browsers
 *   - "crawlers": Only display search engine crawlers
 *   - "all": Display all user agents.
 */
function browscap_top_useragents($view = 'all') {
  if ($view == 'all') {
    $result = db_query('SELECT SUM(counter) FROM {browscap_statistics}');
    $total = db_result($result);
    if (!$total) $total = 1;
    $query = "SELECT parent,counter,(100*counter)/$total as percent,is_crawler FROM {browscap_statistics}";
    $query_cnt = 'SELECT COUNT(parent) FROM {browscap_statistics}';
    $title = t('Top user agents');
    $header = array(
      array('data' => t('User agent'), 'field' => 'parent'),
      array('data' => t('Count'), 'field' => 'counter', 'sort' => 'desc'),
      array('data' => t('Percent'), 'field' => 'percent'),
      array('data' => t('Crawler?'), 'field' => 'is_crawler')
    );
  }
  elseif ($view == 'browsers') {
    $result = db_query('SELECT SUM(counter) FROM {browscap_statistics} WHERE is_crawler=0');
    $total = db_result($result);
    if (!$total) $total = 1;
    $query = "SELECT parent,counter,(100*counter)/$total as percent FROM {browscap_statistics} WHERE is_crawler=0";
    $query_cnt = 'SELECT COUNT(parent) FROM {browscap_statistics} WHERE is_crawler=0';
    $title = t('Top browsers');
    $header = array(
      array('data' => t('Browser'), 'field' => 'parent'),
      array('data' => t('Count'), 'field' => 'counter', 'sort' => 'desc'),
      array('data' => t('Percent'), 'field' => 'percent')
    );
  }
  else {
    $result = db_query('SELECT SUM(counter) FROM {browscap_statistics} WHERE is_crawler=1');
    $total = db_result($result);
    if (!$total) $total = 1;
    $query = "SELECT parent,counter,(100*counter)/$total as percent FROM {browscap_statistics} WHERE is_crawler=1";
    $query_cnt = 'SELECT COUNT(parent) FROM {browscap_statistics} WHERE is_crawler=1';
    $title = t('Top crawlers');
    $header = array(
      array('data' => t('Crawler'), 'field' => 'parent'),
      array('data' => t('Count'), 'field' => 'counter', 'sort' => 'desc'),
      array('data' => t('Percent'), 'field' => 'percent')
    );
  }

  drupal_set_title($title);

  $query .= tablesort_sql($header);

  $result = pager_query($query, 50, 0, $query_cnt);
  $rows = array();

  while ($useragent = db_fetch_object($result)) {
    if (db_result(db_query_range("SELECT useragent FROM {browscap} WHERE useragent = '%s'", $useragent->parent, 0, 1))) {
      $parent = l($useragent->parent, 'admin/reports/browscap/useragent/'. urlencode($useragent->parent));
    }
    else {
      $parent = check_plain($useragent->parent);
    }
    if ($view == 'all') {
      if ($useragent->is_crawler) {
        $is_crawler = t('Yes');
      }
      else {
        $is_crawler = t('No');
      }
      $rows[] = array($parent, $useragent->counter, $useragent->percent, $is_crawler);
    }
    else {
      $rows[] = array($parent, $useragent->counter, $useragent->percent);
    }
  }
  if ($pager = theme('pager', NULL, 50, 0)) {
    $rows[] = array(array('data' => $pager, 'colspan' => 2));
  }

  $output = '';
  if (empty($rows)) {
    $output .= t('It appears that your site has not recorded any visits. If you want to record the visitors to your site you can enable "Monitor browsers" on the <a href="!settings_uri">Browscap settings screen</a>.', array('!settings_uri' => url('admin/settings/browscap')));
  }
  $output .= theme('table', $header, $rows);

  print theme('page', $output, $title);
}

/**
 * Provide data about the current browser or a known user agent string.
 *
 * @param string $useragent
 *   Optional user agent string to test.  If empty use the value from the current request.
 * @return array
 *  An array of data about the user agent.
 */
function browscap_get_browser($useragent = NULL) {
  if (!$useragent) {
    $useragent = $_SERVER['HTTP_USER_AGENT'];
  }
  // Cache the results
  $cacheid = $useragent;
  $cache = cache_get($cacheid, 'cache_browscap');
  if ((!empty($cache)) and ($cache->created > time() - 60*60*24)) {
    // Found a fresh entry in the cache
    $browserinfo = $cache->data;
  }
  else {
    // Note the 'backwards' use of LIKE - the useragent column contains
    // the wildcarded pattern to match against our full-length string
    // The ORDER BY chooses the most-specific matching pattern
    $browserinfo = db_fetch_object(db_query_range(
      "SELECT * from {browscap} WHERE '%s' LIKE useragent ORDER BY LENGTH(useragent) DESC",
      $useragent, 0, 1));
    // A couple of fieldnames not in our database, provided for
    // compatibility with PHP's get_browser()
    //$browserinfo->tables = $browserinfo->htmltables;
    cache_set($cacheid, $browserinfo, 'cache_browscap');
  }
  if (isset($browserinfo) && isset($browserinfo->data)) {
    $info = unserialize($browserinfo->data);
    $info['useragent'] = $useragent;
    $info['browser_name_pattern'] = strtr($browserinfo->useragent, '%_', '*?');
    return $info;
  }
}

/**
 * Determine whether the current visitor
 *
 * @param string $useragent
 *   Optional user agent string.
 */
function browscap_is_crawler($useragent = NULL) {
  $browser = browscap_get_browser($useragent);
  return (bool)$browser['crawler'];
}

// A numeric interpretation of browscap.csv's TRUE/FALSE/default fields
function _browscap_boolean($value) {
  switch ($value) {
    case 'TRUE':
    case 'true':
      return 1;
    case 'FALSE':
    case 'false':
    case 'default':
    default:
      return 0;
  }
}

/**
 * If there's a new version of browscap.csv, fetch it and update the
 * database.
 */
function _browscap_import($cron = TRUE) {
  // Politely check the version for updates before fetching the file
  $versionpage = drupal_http_request('http://browsers.garykeith.com/versions/version-number.asp');
  if (isset($versionpage->error)) {
    watchdog('browscap', 'Couldn\'t check version: '. $versionpage->error);
    if (!$cron) {
      drupal_set_message(t('Couldn\'t check version: ') . $versionpage->error, 'error');
    }
    return;
  }
  $browscapversion = trim($versionpage->data);
  $oldversion = variable_get('browscap_version', 'Never fetched');
  if ($browscapversion == $oldversion) {
    // No update, nothing to do here
    watchdog('browscap', 'No new version of browscap to import');
    if (!$cron) {
      drupal_set_message(t('No new version of browscap to import'));
    }
    return;
  }

  // Fetch the new version, and dump it in the temp directory
  $server = $_SERVER['SERVER_NAME'];
  $path = variable_get('file_directory_temp', '/tmp');
  $browscapfile = "$path/browscap_$server.ini";

  $browscap = drupal_http_request('http://browsers.garykeith.com/stream.asp?PHP_BrowsCapINI');
  if (isset($browscap->error) || empty($browscap)) {
    watchdog('browscap', t("Couldn't retrieve updated browscap: ") . $browscap->error);
    if (!$cron) {
      drupal_set_message(t("Couldn't retrieve updated browscap: ") . $browscap->error);
    }
    return;
  }
  $browscapfp = fopen($browscapfile, "w");
  fwrite($browscapfp, $browscap->data);
  fclose($browscapfp);

  $a = parse_ini_file($browscapfile, TRUE);
  if ($a) {
    // the first entry in the array is the version info
    $version = array_shift($a);
    foreach ($a as $key => $vals) {
      $e = $vals;
      // some recursive magic!
      $last_parent = array();
      while (isset($vals['Parent']) && $vals['Parent'] !== $last_parent) {
        $vals = isset($a[$vals['Parent']]) ? $a[$vals['Parent']] : array();
        $e = array_merge($vals, $e);
        $last_parent = $vals;
      }
      $useragent = strtr($key, '*?', '%_');
      $e = array_change_key_case($e);
      db_query("DELETE FROM {browscap} WHERE useragent = '%s'", $useragent);
      db_query("INSERT INTO {browscap} (useragent, data) VALUES ('%s', '%s')", $useragent, serialize($e));
    }

    cache_clear_all('*', 'cache_browscap', TRUE);
    variable_set('browscap_version', $browscapversion);
    watchdog('browscap', 'New version of browscap imported: '. $browscapversion);
    if (!$cron) {
      drupal_set_message(t('New version of browscap imported: ') . $browscapversion);
    }
  }
}

/*
 * Undo a recorded browser visit by request
 *
 * This function serves the statistics_filter module, enabling it
 * to ignore visits from specified roles.
 */
function browscap_unmonitor() {
  // No point if statistics aren't enabled
  if (!module_exists('statistics')) {
    return;
  }

  // If monitoring is enabled, unrecord the browser
  if (variable_get('browscap_monitor', FALSE)) {
    $browser = browscap_get_browser();
    $browserstring = trim($browser->parent);
    if ($browserstring == '' or $browserstring == 'Default Browser') {
      $browserstring = trim($_SERVER['HTTP_USER_AGENT']);
    }
    db_query("UPDATE {browscap_statistics} SET counter = counter - 1, is_crawler=%d ".
      "WHERE parent='%s'", $browser->crawler, $browserstring);
  }
}

/**
 * Loads details about a given useragent. Also used as a menu object loader.
 *
 * @param $useragent
 *   The name of the useragent to load.
 * @return
 *   The useragent array, FALSE otherwise.
 */
function browscap_useragent_load($useragent = NULL) {
  if (empty($useragent)) {
    return FALSE;
  }
  $row = db_fetch_object(db_query('SELECT * FROM {browscap} WHERE useragent = "%s"', $useragent));
  if (!$row) {
    return FALSE;
  }
  return unserialize($row->data);
}

/**
 * Page callback to show details about known useragents.
 *
 * @param $useragent
 *   The useragent object, loaded from the database.
 * @return string an HTMl blob representing the data about this useragent.
 */
function browscap_useragent_properties($useragent = NULL) {
  drupal_set_title(check_plain($useragent['browser'] .' '. $useragent['version']));
  $headers = array(t('Property'), t('Value'));
  foreach ($useragent as $key => $val) {
    $rows[] = array(check_plain($key), check_plain($val));
  }
  $output = theme('table', $headers, $rows);
  return $output;
}