<?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_EXTENSIONS', '7z|aac|avi|csv|doc|exe|flv|gif|gz|jpe?g|js|mp(3|4|e?g)|mov|pdf|phps|png|ppt|rar|sit|tar|torrent|txt|wma|wmv|xls|xml|zip');

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_perm() {
  return array('administer google analytics', 'use PHP for tracking visibility');
}

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 google analytics'),
      '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', '');

  // 1. Check if the GA account number has a value.
  // 2. Track page views based on visibility value.
  // 3. Check if we should track the currently active user's role.
  if (!empty($id) && _googleanalytics_visibility() && _googleanalytics_track($user)) {

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

    // Should a local cached copy of urchin.js or ga.js be used?
    $js_file = ($legacy_version) ? 'urchin.js' : 'ga.js';
    $url = 'http://www.google-analytics.com/'. $js_file;

    if (variable_get('googleanalytics_cache', 0) && (variable_get('file_downloads', FILE_DOWNLOADS_PUBLIC) == FILE_DOWNLOADS_PUBLIC) && $source = _googleanalytics_cache($url)) {
      drupal_add_js($source, 'module', $scope);
    }
    else {
      $script = 'var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");';
      $script .= 'document.write(unescape("%3Cscript src=\'" + gaJsHost + "google-analytics.com/'. $js_file .'\' type=\'text/javascript\'%3E%3C/script%3E"));';
      drupal_add_js($script, 'inline', $scope);
    }

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

    // 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)) .');';
        }
      }
    }

    // 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';
        }
      }
    }

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

    // Should the legacy code be used?
    $script = '';
    if ($legacy_version) {
      $script .= '_uacct = '. drupal_to_js($id) .';';
      if (!empty($segmentation)) {
        $script .= $segmentation;
      }
      if (!empty($codesnippet)) {
        $script .= $codesnippet;
      }
      $script .= 'urchinTracker('. $url_custom .');';
    }
    else {
      $script .= 'var pageTracker = _gat._getTracker('. drupal_to_js($id) .');';
      $script .= 'pageTracker._initData();';
      if (!empty($segmentation)) {
        $script .= $segmentation;
      }
      if (!empty($codesnippet)) {
        $script .= $codesnippet;
      }
      $script .= 'pageTracker._trackPageview('. $url_custom .');';
    }

    drupal_add_js($script, 'inline', 'footer');
  }
}

/**
 * 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.
  $form['roles'] = array(
    '#type' => 'fieldset',
    '#title' => t('User role tracking'),
    '#collapsible' => TRUE,
    '#description' => t('Define what user roles should be tracked by Google Analytics.'),
  );

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

  $roles = _googleanalytics_user_roles();
  foreach ($roles as $rid => $rname) {
    $form['roles']['googleanalytics_track_'. $rid] = array(
      '#type' => 'checkbox',
      '#title' => check_plain($rname),
      '#default_value' => variable_get('googleanalytics_track_'. $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
    );
  }

  // Link specific configurations.
  $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_EXTENSIONS),
    '#description' => t('A pipe separated list of file extensions that should be tracked when clicked. Example: !extensions', array('!extensions' => GA_TRACKFILES_EXTENSIONS))
  );

  // Page specific visibility configurations.
  $form['page_vis_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Page specific tracking settings'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );

  $access = user_access('use PHP for tracking visibility');
  $visibility = variable_get('googleanalytics_visibility', 0);
  $pages = variable_get('googleanalytics_pages', '');

  if ($visibility == 2 && !$access) {
    $form['page_vis_settings'] = array();
    $form['page_vis_settings']['visibility'] = array('#type' => 'value', '#value' => 2);
    $form['page_vis_settings']['pages'] = array('#type' => 'value', '#value' => $pages);
  }
  else {
    $options = array(t('Add to every page except the listed pages.'), t('Add to only the listed pages.'));
    $description = t("Enter one page per line as Drupal paths. The '*' character is a wildcard. Example paths are %blog for the blog page and %blog-wildcard for every personal blog. %front is the front page.", array('%blog' => 'blog', '%blog-wildcard' => 'blog/*', '%front' => '<front>'));

    if ($access) {
      $options[] = t('Add if the following PHP code returns <code>TRUE</code> (PHP-mode, experts only).');
      $description .= ' '. t('If the PHP-mode is chosen, enter PHP code between %php. Note that executing incorrect PHP-code can break your Drupal site.', array('%php' => '<?php ?>'));
    }
    $form['page_vis_settings']['googleanalytics_visibility'] = array(
      '#type' => 'radios',
      '#title' => t('Add tracking to specific pages'),
      '#options' => $options,
      '#default_value' => $visibility,
    );
    $form['page_vis_settings']['googleanalytics_pages'] = array(
      '#type' => 'textarea',
      '#title' => t('Pages'),
      '#default_value' => $pages,
      '#description' => $description,
    );
  }

  // Advanced feature configurations.
  $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('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('Custom JavaScript code'),
    '#default_value' => variable_get('googleanalytics_codesnippet', ''),
    '#rows' => 5,
    '#description' => t('You can add custom Google Analytics <a href="@snippets">code snippets</a> here. These will be added to every page that Google Analytics appears on. <strong>Do not include the &lt;script&gt; tags</strong>, and always end your code with a semicolon (;).', array('@snippets' => 'http://drupal.org/node/248699'))
  );

  $form['advanced']['googleanalytics_js_scope'] = array(
    '#type' => 'select',
    '#title' => t('JavaScript scope'),
    '#description' => t("<strong>Warning:</strong> Google recommends adding the external JavaScript files to footer for performance reasons."),
    '#options' => array(
      'footer' => t('Footer'),
      'header' => t('Header'),
    ),
    '#default_value' => variable_get('googleanalytics_js_scope', 'footer'),
  );

  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.'));
  }
}

function googleanalytics_admin_settings_form_submit($form_id, $form_values) {
  // Trim pages variable.
  $form_values['googleanalytics_pages'] = trim($form_values['googleanalytics_pages']);
  system_settings_form_submit($form_id, $form_values);
}

/**
 * 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) {
  $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;
}

/**
 * Based on visibility setting this function returns TRUE if GA code should
 * be added to the current page and otherwise FALSE.
 */
function _googleanalytics_visibility() {

  $visibility = variable_get('googleanalytics_visibility', 0);
  $pages = variable_get('googleanalytics_pages', '');

  // Match path if necessary.
  if (!empty($pages)) {
    if ($visibility < 2) {
      $path = drupal_get_path_alias($_GET['q']);
      // Compare with the internal and path alias (if any).
      $page_match = _googleanalytics_match_path($path, $pages);
      if ($path != $_GET['q']) {
        $page_match = $page_match || _googleanalytics_match_path($_GET['q'], $pages);
      }
      // When $visibility has a value of 0, the block is displayed on
      // all pages except those listed in $pages. When set to 1, it
      // is displayed only on those pages listed in $pages.
      $page_match = !($visibility xor $page_match);
    }
    else {
      $page_match = drupal_eval($pages);
    }
  }
  else {
    $page_match = TRUE;
  }

  return $page_match;
}

/**
 * D6 backport of drupal_match_path().
 */
function _googleanalytics_match_path($path, $patterns) {
  static $regexps;

  if (!isset($regexps[$patterns])) {
    $regexps[$patterns] = '/^('. preg_replace(array('/(\r\n?|\n)/', '/\\\\\*/', '/(^|\|)\\\\<front\\\\>($|\|)/'), array('|', '.*', '\1'. preg_quote(variable_get('site_frontpage', 'node'), '/') .'\2'), preg_quote($patterns, '/')) .')$/';
  }
  return preg_match($regexps[$patterns], $path);
}

/**
 * D6 backport orders core standard roles on top and translate core roles.
 */
function _googleanalytics_user_roles() {
  // System roles take the first two positions.
  $roles = array(
    DRUPAL_ANONYMOUS_RID => NULL,
    DRUPAL_AUTHENTICATED_RID => NULL,
  );

  $result = db_query('SELECT * FROM {role} ORDER BY name');

  while ($role = db_fetch_object($result)) {
    switch ($role->rid) {
      // We only translate the built in role names
      case DRUPAL_ANONYMOUS_RID:
        $roles[$role->rid] = t($role->name);
        break;
      case DRUPAL_AUTHENTICATED_RID:
        $roles[$role->rid] = t($role->name);
        break;
      default:
        $roles[$role->rid] = $role->name;
    }
  }

  // Filter to remove unmatched system roles.
  return array_filter($roles);
}