<?php
// $Id$
/*
 * Drupal Module: GoogleAnalytics
 * Adds the required Javascript to the bottom of all your Drupal pages
 * to allow tracking by the Google Analytics statistics package.
 *
 * @author: Mike Carter <www.ixis.co.uk/contact>
 */

define('GA_TRACKFILES', 'pdf|zip|mp3');

function googleanalytics_help($section) {
  switch ($section) {
    case 'admin/settings/googleanalytics':
      return t('Google Analytics is a free statistics package based on the excellent Urchin system.');
  }
}

function googleanalytics_menu($maycache) {
  $items = array();
  if ($maycache) {
    $items[] = array(
      'path' => 'admin/settings/googleanalytics',
      'title' => t('Google Analytics'),
      'description' => t('Configure the settings used to generate your Google Analytics tracking code.'),
      'callback' => 'drupal_get_form',
      'callback arguments' => 'googleanalytics_admin_settings_form',
      'access' => user_access('administer site configuration'),
      'type' => MENU_NORMAL_ITEM,
    );
  }
  return $items;
}

/**
 * Implementation of hook_footer()  to insert Javascript at the end of the page
 */
function googleanalytics_footer($main = 0) {
  global $user;

  $id = variable_get('googleanalytics_account', '');

  // Check if we should track the currently active user's role
  $track = _googleanalytics_track($user);

  // Don't track page views in the admin sections
  if ($id && (arg(0) != 'admin') && $track == TRUE) {

    $prefix = '://www';

    // Are we on a secure page?
    if (isset($_SERVER['HTTPS']) && !empty($_SERVER['HTTPS']) && (strtolower($_SERVER['HTTPS']) != 'off')) {
      $prefix = 's://ssl';
    }

    // Use the old version of Google Analytics?
    $legacy_version = variable_get('googleanalytics_legacy_version', TRUE);

    // Add User profile segmentation values
    if (is_array($profile_fields = variable_get('googleanalytics_segmentation', '')) && ($user->uid > 0)) {

      $p = module_invoke('profile', 'load_profile', $user);

      $fields = array();
      foreach ($profile_fields as $field => $title) {
        $value = $user->$field;

        if (is_array($value)) {
          $value = implode(',', $value);
        }

        $fields[$field] = $value;
      }

      // Only show segmentation variable if there are specified fields.
      $segmentation = '';
      if (count($fields) > 0) {
        if ($legacy_version) {
          $segmentation = '__utmSetVar('. drupal_to_js(implode(':', $fields)) .');';
        } else {
          $segmentation = 'pageTracker._setVar('. drupal_to_js(implode(':', $fields)) .');';
        }
      }
    }

    // Download tracking
    $path = drupal_get_path('module', 'googleanalytics');
    if (variable_get('googleanalytics_trackfiles', TRUE) && $trackfiles_extensions = variable_get('googleanalytics_trackfiles_extensions', GA_TRACKFILES)) {
      drupal_add_js(array('googleanalytics' => array('trackDownload' => $trackfiles_extensions, 'LegacyVersion' => $legacy_version)), 'setting', 'header');
      drupal_add_js($path .'/downloadtracker.js', 'module', 'footer');
    }

    // Add any custom code snippets if specified
    $codesnippet = variable_get('googleanalytics_codesnippet', '');

    // Should a local cached copy of urchin.js or ga.js be used?
    if (variable_get('googleanalytics_cache', 0) && (variable_get('file_downloads', FILE_DOWNLOADS_PUBLIC) == FILE_DOWNLOADS_PUBLIC)) {
      if ($legacy_version) {
        $source = _googleanalytics_cache('http://www.google-analytics.com/urchin.js');
      }
      else {
        $source = _googleanalytics_cache('http://www.google-analytics.com/ga.js');
      }
      if (!empty($source)) {
        $source = base_path() . $source;
      }
    }
    if (!isset($source)) {
      if ($legacy_version) {
        $source = 'http'. $prefix .'.google-analytics.com/urchin.js';
      }
      else {
        $source = 'http'. $prefix .'.google-analytics.com/ga.js';
      }
    }

    // Site search tracking support.
    $url_custom = '';
    if (module_exists('search') && variable_get('googleanalytics_site_search', FALSE) && arg(0) == 'search') {
      $keys = search_get_keys();
      $url_custom = drupal_to_js(url('search/'. arg(1), 'search='. trim($keys)));
    }

    // Track access denied (403) and file not found (404) pages.
    if (function_exists('drupal_get_headers')) {
      $headers = drupal_get_headers();
      if (strstr($headers, 'HTTP/1.1 403 Forbidden')) {
        if ($legacy_version) {
          // See http://www.google.com/support/analytics/bin/answer.py?answer=86928
          $url_custom = '"/403.html?page=" + _udl.pathname + _udl.search';
        }
        else {
          // See http://www.google.com/support/analytics/bin/answer.py?answer=86927
          $url_custom = '"/403.html?page=" + document.location.pathname + document.location.search + "&from=" + document.referrer';
        }
      }
      elseif (strstr($headers, 'HTTP/1.1 404 Not Found')) {
        if ($legacy_version) {
          $url_custom = '"/404.html?page=" + _udl.pathname + _udl.search';
        }
        else {
          $url_custom = '"/404.html?page=" + document.location.pathname + document.location.search + "&from=" + document.referrer';
        }
      }
    }

    // Should the legacy code be used?
    if ($legacy_version) {
      $script = '<script type="text/javascript" src="'. $source ."\"></script>\n";
      $script .= '<script type="text/javascript">';
      $script .= '_uacct = '. drupal_to_js($id) .';';
      if (!empty($segmentation)) {
        $script .= $segmentation;
      }
      if (!empty($codesnippet)) {
        $script .= $codesnippet;
      }
      $script .= 'urchinTracker('. $url_custom .');';
      $script .= "</script>\n";
    }
    else {
      $script = '<script type="text/javascript">';
      $script .= 'document.write(unescape("%3Cscript src=\''. $source .'\' type=\'text/javascript\'%3E%3C/script%3E"));';
      $script .= "</script>\n";
      $script .= '<script type="text/javascript">';
      $script .= 'var pageTracker = _gat._getTracker('. drupal_to_js($id) .');';
      $script .= 'pageTracker._initData();';
      if (!empty($segmentation)) {
        $script .= $segmentation;
      }
      if (!empty($codesnippet)) {
        $script .= $codesnippet;
      }
      $script .= 'pageTracker._trackPageview('. $url_custom .');';
      $script .= "</script>\n";
    }
    
    return $script;
  }
}

/**
 * Implementation of hook_admin_settings() for configuring the module
 */
function googleanalytics_admin_settings_form() {
  $form['account'] = array(
    '#type' => 'fieldset',
    '#title' => t('Analytics Account Settings'),
    '#collapsible' => FALSE,
  );

  $form['account']['googleanalytics_account'] = array(
    '#type' => 'textfield',
    '#title' => t('Google Analytics account number'),
    '#default_value' => variable_get('googleanalytics_account', 'UA-'),
    '#size' => 15,
    '#maxlength' => 20,
    '#required' => TRUE,
    '#description' => t('The user account number (UA-xxxxxx-x) is unique to the websites domain. You can obtain a user account from the <a href="@url">Google Analytics</a> website.', array('@url' => 'http://www.google.com/analytics/'))
  );

  $form['account']['googleanalytics_legacy_version'] = array(
    '#type' => 'checkbox',
    '#title' => t('Legacy Google Analytics'),
    '#default_value' => variable_get("googleanalytics_legacy_version", TRUE),
    '#description' => t('This will enable Legacy Google Analytics instead of most recent.<br /> Please note that Legacy Google Analytics will not receive feature updates and is not compatible with new features.'),
   );

  // Render the role overview.
  $result = db_query('SELECT * FROM {role} ORDER BY name');

  $form['roles'] = array(
    '#type' => 'fieldset',
    '#title' => t('User Role Tracking'),
    '#collapsible' => TRUE,
    '#description' => t('Define what user roles should be tracked by Google Analytics. <strong>Note:</strong> Drupal Admin pages are never tracked.'),
  );

  $form['roles']['googleanalytics_track__user1'] = array(
    '#type' => 'checkbox',
    '#title' => t('Admin (user 1)'),
    '#default_value' => variable_get('googleanalytics_track__user1', FALSE),
  );

  while ($role = db_fetch_object($result)) {
    $form['roles']['googleanalytics_track_'. $role->rid] = array(
      '#type' => 'checkbox',
      '#title' => check_plain($role->name),
      '#default_value' => variable_get('googleanalytics_track_'. $role->rid, FALSE),
    );
  }

  $form['segmentation'] = array(
    '#type' => 'fieldset',
    '#title' => t('User Segmentation'),
    '#collapsible' => TRUE,
    '#description' => t('If your users have profile fields completed, you can track your logged in users based on a defined profile field.')
  );

  if (!module_exists('profile')) {
    $form['segmentation']['profile'] = array(
      '#type' => 'markup',
      '#value' => t('You need to activate the !profile to use this feature.', array('!profile' => l(t('Profile module'), 'admin/build/modules'))),
      '#prefix' => '<p>',
      '#suffix' => '</p>'
      );
  }
  else {
    // Compile a list of fields to show.
    $fields = array(
      'uid' => t('User ID'),
      'name' => t('Username'),
      'roles' => t('User Roles')
    );
    $result = db_query('SELECT name, title, type, weight FROM {profile_fields} ORDER BY weight');
    while ($record = db_fetch_object($result)) {
      $fields[$record->name] = $record->title;
    }

    $form['segmentation']['googleanalytics_segmentation'] = array(
      '#type' => 'select',
      '#title' => t('Track'),
      '#description' => t('Selecting one or more values allows you to track users by profile values rather than simply an IP address. To select multiple items, hold down CTRL whilst selecting fields.'),
      '#default_value' => variable_get('googleanalytics_segmentation', ''),
      '#options' => $fields,
      '#size' => 10,
      '#multiple' => TRUE
    );
  }

  $form['linktracking'] = array(
    '#type' => 'fieldset',
    '#title' => t('Link tracking'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
  );
  $form['linktracking']['googleanalytics_trackfiles'] = array(
    '#type' => 'checkbox',
    '#title' => t('Track files'),
    '#default_value' => variable_get('googleanalytics_trackfiles', TRUE),
    '#description' => t('Enables tracking of files based on below file extensions list.')
  );
  $form['linktracking']['googleanalytics_trackfiles_extensions'] = array(
    '#type' => 'textfield',
    '#title' => t('File Extensions To Track'),
    '#default_value' => variable_get('googleanalytics_trackfiles_extensions', GA_TRACKFILES),
    '#description' => t('A pipe seperated list of file extensions that should be tracked when clicked. Example !extensions', array('!extensions' => GA_TRACKFILES))
  );

  $form['advanced'] = array(
    '#type' => 'fieldset',
    '#title' => t('Advanced'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
    '#description' => t('You can add custom Google Analytics code here.')
  );

  $form['advanced']['googleanalytics_cache'] = array(
    '#type' => 'checkbox',
    '#title' => t('Cache tracking code file locally'),
    '#description' => t("If checked, the tracking code file is received from Google Analytics and cached locally. It is updated daily from Google's servers to ensure updates to tracking code are reflected in the local copy. Do not activate this until after Google Analytics has confirmed your tracker."),
    '#default_value' => variable_get('googleanalytics_cache', 0),
  );
  if (variable_get('file_downloads', FILE_DOWNLOADS_PUBLIC) == FILE_DOWNLOADS_PRIVATE) {
    $form['advanced']['googleanalytics_cache']['#disabled'] = TRUE;
    $form['advanced']['googleanalytics_cache']['#description'] .= ' '. t('<a href="!url">Public file transfers</a> must be enabled to allow local caching.', array('!url' => url('admin/settings/file-system', drupal_get_destination())));
  }

  $site_search_dependencies = '<div class="admin-dependencies">';
  $site_search_dependencies .= t('Depends on: !dependencies', array('!dependencies' => (module_exists('search') ? 'Search'. t(' (<span class="admin-enabled">enabled</span>)') : 'Search'. t(' (<span class="admin-disabled">disabled</span>)'))));
  $site_search_dependencies .= '</div>';

  // Google already have many translations, if not - they display a note to change the language.
  global $locale;
  $form['advanced']['googleanalytics_site_search'] = array(
    '#type' => 'checkbox',
    '#title' => t('Do Track Internal Search'),
    '#description' => t('If checked, internal search keywords are tracked. You must configure your Google account to use the internal query parameter <em>search</em>. For more information see <a href="!url">How do I set up Site Search for my profile</a>.', array('!url' => 'http://www.google.com/support/analytics/bin/answer.py?hl='. $locale .'&amp;answer=75817')) . $site_search_dependencies,
    '#default_value' => variable_get('googleanalytics_site_search', FALSE),
    '#disabled' => (module_exists('search') ? FALSE : TRUE),
  );

  $form['advanced']['googleanalytics_codesnippet'] = array(
    '#type' => 'textarea',
    '#title' => t('JavaScript Code'),
    '#default_value' => variable_get('googleanalytics_codesnippet', ''),
    '#rows' => 15,
    '#description' => t('Paste <a href="@snippets">custom code snippets here</a>. These will be added to every page that Google Analytics appears on. For help with this feature see the <a href="@blog">cutroni.com blog</a>. <strong>Do not include the &lt;script&gt; tags</strong>, and always end your code with a semicolon (;).', array('@snippets' => 'http://drupal.org/node/39282', '@blog' => 'http://cutroni.com/blog/'))
  );

  return system_settings_form($form);
}

function googleanalytics_admin_settings_form_validate($form_id, $form_values) {
  if (!preg_match('/^UA-\d{4,}-\d+$/', $form_values['googleanalytics_account'])) {
    form_set_error('googleanalytics_account', t('A valid Google Analytics account number is case sensitive and formated like UA-xxxxxx-x.'));
  }
}

/**
 * Implementation of hook_requirements().
 */
function googleanalytics_requirements($phase) {
  $requirements = array();

  if ($phase == 'runtime') {
    // Raise warning if Google user account has not been set yet.
    if (!preg_match('/^UA-\d{4,}-\d+$/', variable_get('googleanalytics_account', 'UA-'))) {
      $requirements['googleanalytics'] = array(
        'title' => t('Google Analytics module'),
        'description' => t('Google Analytics module has not been configured yet. Please configure its settings from the <a href="@url">Google Analytics settings page</a>.', array('@url' => url('admin/settings/googleanalytics'))),
        'severity' => REQUIREMENT_ERROR,
        'value' => t('Not configured'),
      );
    }
  }

  return $requirements;
}

/**
 * Implementation of hook_cron().
 */
function googleanalytics_cron() {
  // Regenerate the google analytics urchin.js or ga.js every day.
  if (time() - variable_get('googleanalytics_last_cache', 0) >= 86400) {
    // Legacy google analytics version.
    file_delete(file_directory_path() .'/googleanalytics/urchin.js');

    // New google analytics version.
    file_delete(file_directory_path() .'/googleanalytics/ga.js');
    variable_set('googleanalytics_last_cache', time());
  }
}

/**
 * Download and cache the urchin.js file locally.
 * @param $location
 *   The full URL to the external javascript file.
 * @return mixed
 *   The path to the local javascript file on success, boolean FALSE on failure.
 */
function _googleanalytics_cache($location = 'http://www.google-analytics.com/urchin.js') {
  $directory = file_directory_path() .'/googleanalytics';
  $file_destination = $directory .'/'. basename($location);
  if (!file_exists($file_destination)) {
    $result = drupal_http_request($location);
    if ($result->code == 200) {
      // Check that the files directory is writable
      if (file_check_directory($directory, FILE_CREATE_DIRECTORY)) {
        return file_save_data($result->data, $directory .'/'. basename($location), FILE_EXISTS_REPLACE);
      }
    }
  }
  else {
    return $file_destination;
  }
}

/**
 *
 * @param $account
 *   A user object containing an array of roles to check
 * @return boolean
 *   A decision on if the current user is being tracked by GAnalytics
 */
function _googleanalytics_track($account) {
  // By default we don't track users.
  $track = FALSE;

  foreach (array_keys($account->roles) as $role) {
    // Add the tracking code if user is member of one role that should be tracked.
    if (variable_get('googleanalytics_track_'. $role, FALSE)) {
      $track = TRUE;
    }
  }

  // Handle behavior for administrative user 1.
  if ($account->uid == 1 && variable_get('googleanalytics_track__user1', FALSE)) {
    // Enable tracking of user 1 if tracking for "authenticated user" is disabled.
    $track = TRUE;
  }
  elseif ($account->uid == 1 && !variable_get('googleanalytics_track__user1', FALSE)) {
    // User 1 is a member of "authenticated user". Disable user tracking
    // if user 1 shouldn't, but "authenticated user" should be tracked.
    $track = FALSE;
  }

  return $track;
}