<?php
// $Id: xmlsitemap.module,v 1.104 2011-02-09 21:45:59 davereid Exp $

/**
 * @defgroup xmlsitemap XML sitemap
 */

/**
 * @file
 * Main file for the xmlsitemap module.
 */

/**
 * The maximum number of links in one sitemap chunk file.
 */
define('XMLSITEMAP_MAX_SITEMAP_LINKS', 50000);

/**
 * The maximum filesize of a sitemap chunk file.
 */
define('XMLSITEMAP_MAX_SITEMAP_FILESIZE', 10485760);

define('XMLSITEMAP_FREQUENCY_YEARLY', 31449600); // 60 * 60 * 24 * 7 * 52
define('XMLSITEMAP_FREQUENCY_MONTHLY', 2419200); // 60 * 60 * 24 * 7 * 4
define('XMLSITEMAP_FREQUENCY_WEEKLY', 604800); // 60 * 60 * 24 * 7
define('XMLSITEMAP_FREQUENCY_DAILY', 86400); // 60 * 60 * 24
define('XMLSITEMAP_FREQUENCY_HOURLY', 3600); // 60 * 60
define('XMLSITEMAP_FREQUENCY_ALWAYS', 60);

/**
 * Short lastmod timestamp format.
 */
define('XMLSITEMAP_LASTMOD_SHORT', 'Y-m-d');

/**
 * Medium lastmod timestamp format.
 */
define('XMLSITEMAP_LASTMOD_MEDIUM', 'Y-m-d\TH:i\Z');

/**
 * Long lastmod timestamp format.
 */
define('XMLSITEMAP_LASTMOD_LONG', 'c');

/**
 * The default inclusion status for link types in the sitemaps.
 */
define('XMLSITEMAP_STATUS_DEFAULT', 0);

/**
 * The default priority for link types in the sitemaps.
 */
define('XMLSITEMAP_PRIORITY_DEFAULT', 0.5);

/**
 * Implements hook_hook_info().
 */
function xmlsitemap_hook_info() {
  $hooks = array(
    'xmlsitemap_link_info',
    'xmlsitemap_link_info_alter',
    'xmlsitemap_link_alter',
    'xmlsitemap_index_links',
    'xmlsitemap_context_info',
    'xmlsitemap_context_info_alter',
    'xmlsitemap_context_url_options',
    'xmlsitemap_context',
    'xmlsitemap_sitemap_insert',
    'xmlsitemap_sitemap_update',
    'xmlsitemap_sitemap_operations',
    'xmlsitemap_sitemap_delete',
    'xmlsitemap_sitemap_link_url_options_alter',
    'query_xmlsitemap_generate_alter',
    'query_xmlsitemap_link_bundle_access_alter',
    'form_xmlsitemap_sitemap_edit_form_alter',
  );

  $hooks = array_combine($hooks, $hooks);
  foreach ($hooks as $hook => $info) {
    $hooks[$hook] = array('group' => 'xmlsitemap');
  }

  return $hooks;
}

/**
 * Implements hook_help().
 */
function xmlsitemap_help($path, $arg) {
  $output = '';

  switch ($path) {
    case 'admin/help/xmlsitemap':
    case 'admin/config/search/xmlsitemap/settings/%/%/%':
    case 'admin/config/search/xmlsitemap/edit/%':
    case 'admin/config/search/xmlsitemap/delete/%':
      return;
    case 'admin/help#xmlsitemap':
      break;
    case 'admin/config/search/xmlsitemap':
      break;
    case 'admin/config/search/xmlsitemap/rebuild':
      $output .= '<p>' . t("This action rebuilds your site's XML sitemap and regenerates the cached files, and may be a lengthy process. If you just installed XML sitemap, this can be helpful to import all your site's content into the sitemap. Otherwise, this should only be used in emergencies.") . '</p>';
  }

  if (arg(0) == 'admin' && strpos($path, 'xmlsitemap') !== FALSE && user_access('administer xmlsitemap')) {
    module_load_include('inc', 'xmlsitemap');
    if ($arg[1] == 'config') {
      // Alert the user to any potential problems detected by hook_requirements.
      xmlsitemap_check_status();
    }
    $output .= _xmlsitemap_get_blurb();
  }

  return $output;
}

/**
 * Implements hook_perm().
 */
function xmlsitemap_permission() {
  $permissions['administer xmlsitemap'] = array(
    'title' => t('Administer XML sitemap settings.'),
  );
  return $permissions;
}

/**
 * Implements hook_menu().
 */
function xmlsitemap_menu() {
  $items['admin/config/search/xmlsitemap'] = array(
    'title' => 'XML sitemap',
    'description' => "Configure your site's XML sitemaps to help search engines find and index pages on your site.",
    'page callback' => 'drupal_get_form',
    'page arguments' => array('xmlsitemap_sitemap_list_form'),
    'access arguments' => array('administer xmlsitemap'),
    'file' => 'xmlsitemap.admin.inc',
  );
  $items['admin/config/search/xmlsitemap/list'] = array(
    'title' => 'List',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $items['admin/config/search/xmlsitemap/add'] = array(
    'title' => 'Add new XML sitemap',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('xmlsitemap_sitemap_edit_form'),
    'access arguments' => array('administer xmlsitemap'),
    'type' => MENU_LOCAL_ACTION,
    'file' => 'xmlsitemap.admin.inc',
    'modal' => TRUE,
    'options' => array('modal' => TRUE),
  );
  $items['admin/config/search/xmlsitemap/edit/%xmlsitemap_sitemap'] = array(
    'title' => 'Edit XML sitemap',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('xmlsitemap_sitemap_edit_form', 5),
    'access arguments' => array('administer xmlsitemap'),
    'file' => 'xmlsitemap.admin.inc',
    'modal' => TRUE,
  );
  $items['admin/config/search/xmlsitemap/delete/%xmlsitemap_sitemap'] = array(
    'title' => 'Delete XML sitemap',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('xmlsitemap_sitemap_delete_form', 5),
    'access arguments' => array('administer xmlsitemap'),
    'file' => 'xmlsitemap.admin.inc',
    'modal' => TRUE,
  );

  $items['admin/config/search/xmlsitemap/settings'] = array(
    'title' => 'Settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('xmlsitemap_settings_form'),
    'access arguments' => array('administer xmlsitemap'),
    'type' => MENU_LOCAL_TASK,
    'file' => 'xmlsitemap.admin.inc',
    'weight' => 10,
  );
  $items['admin/config/search/xmlsitemap/settings/%xmlsitemap_link_bundle/%'] = array(
    'load arguments' => array(6),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('xmlsitemap_link_bundle_settings_form', 5),
    'access callback' => 'xmlsitemap_link_bundle_access',
    'access arguments' => array(5),
    'file' => 'xmlsitemap.admin.inc',
    'modal' => TRUE,
  );

  $items['admin/config/search/xmlsitemap/rebuild'] = array(
    'title' => 'Rebuild links',
    'description' => 'Rebuild the site map.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('xmlsitemap_rebuild_form'),
    'access callback' => '_xmlsitemap_rebuild_form_access',
    'type' => MENU_LOCAL_TASK,
    'file' => 'xmlsitemap.admin.inc',
    'weight' => 20,
  );

  $items['sitemap.xml'] = array(
    'page callback' => 'xmlsitemap_output_chunk',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
    'file' => 'xmlsitemap.pages.inc',
  );
  $items['sitemap.xsl'] = array(
    'page callback' => 'xmlsitemap_output_xsl',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
    'file' => 'xmlsitemap.pages.inc',
  );

  return $items;
}

/**
 * Menu access callback; determines if the user can use the rebuild links page.
 */
function _xmlsitemap_rebuild_form_access() {
  module_load_include('generate.inc', 'xmlsitemap');
  $rebuild_types = xmlsitemap_get_rebuildable_link_types();
  return !empty($rebuild_types) && user_access('administer xmlsitemap');
}

/**
 * Implements hook_cron().
 *
 * @todo Use new Queue system. Need to add {sitemap}.queued.
 * @todo Regenerate one at a time?
 */
function xmlsitemap_cron() {
  // If there were no new or changed links, skip.
  if (!variable_get('xmlsitemap_regenerate_needed', FALSE)) {
    return;
  }

  // If the minimum sitemap lifetime hasn't been passed, skip.
  $lifetime = REQUEST_TIME - variable_get('xmlsitemap_generated_last', 0);
  if ($lifetime < variable_get('xmlsitemap_minimum_lifetime', 0)) {
    return;
  }

  // Regenerate the sitemap XML files.
  module_load_include('generate.inc', 'xmlsitemap');
  xmlsitemap_run_unprogressive_batch('xmlsitemap_regenerate_batch');
}

/**
 * Implements hook_modules_enabled().
 */
function xmlsitemap_modules_enabled(array $modules) {
  cache_clear_all('xmlsitemap:', 'cache', TRUE);
}

/**
 * Implements hook_modules_disabled().
 */
function xmlsitemap_modules_disabled(array $modules) {
  cache_clear_all('xmlsitemap:', 'cache', TRUE);
}

/**
 * Implements hook_robotstxt().
 */
function xmlsitemap_robotstxt() {
  if ($sitemap = xmlsitemap_sitemap_load_by_context()) {
    $robotstxt[] = 'Sitemap: ' . url($sitemap->uri['path'], $sitemap->uri['options']);
    return $robotstxt;
  }
}

/**
 * Internal default variables for xmlsitemap_var().
 */
function xmlsitemap_variables() {
  return array(
    'xmlsitemap_rebuild_needed' => FALSE,
    'xmlsitemap_regenerate_needed' => FALSE,
    'xmlsitemap_minimum_lifetime' => 0,
    'xmlsitemap_generated_last' => 0,
    'xmlsitemap_xsl' => 1,
    'xmlsitemap_prefetch_aliases' => 1,
    'xmlsitemap_chunk_size' => 'auto',
    'xmlsitemap_batch_limit' => 100,
    'xmlsitemap_path' => 'xmlsitemap',
    'xmlsitemap_base_url' => $GLOBALS['base_url'],
    'xmlsitemap_developer_mode' => 0,
    'xmlsitemap_frontpage_priority' => 1.0,
    'xmlsitemap_frontpage_changefreq' => XMLSITEMAP_FREQUENCY_DAILY,
    'xmlsitemap_lastmod_format' => XMLSITEMAP_LASTMOD_MEDIUM,
    'xmlsitemap_gz' => FALSE,
    // Removed variables are set to NULL so they can still be deleted.
    'xmlsitemap_regenerate_last' => NULL,
    'xmlsitemap_custom_links' => NULL,
    'xmlsitemap_priority_default' => NULL,
    'xmlsitemap_languages' => NULL,
    'xmlsitemap_max_chunks' => NULL,
    'xmlsitemap_max_filesize' => NULL,
  );
}

/**
 * Internal implementation of variable_get().
 */
function xmlsitemap_var($name, $default = NULL) {
  $defaults = &drupal_static(__FUNCTION__);
  if (!isset($defaults)) {
    $defaults = xmlsitemap_variables();
  }

  $name = 'xmlsitemap_' . $name;

  // @todo Remove when stable.
  if (!isset($defaults[$name])) {
    trigger_error(strtr('Default variable for %variable not found.', array('%variable' => drupal_placeholder($name))));
  }

  return variable_get($name, isset($default) || !isset($defaults[$name]) ? $default : $defaults[$name]);
}

/**
 * @defgroup xmlsitemap_api XML sitemap API.
 * @{
 * This is the XML sitemap API to be used by modules wishing to work with
 * XML sitemap and/or link data.
 */

/**
 * Load an XML sitemap array from the database.
 *
 * @param $smid
 *   An XML sitemap ID.
 *
 * @return
 *   The XML sitemap object.
 */
function xmlsitemap_sitemap_load($smid) {
  $sitemap = xmlsitemap_sitemap_load_multiple(array($smid));
  return $sitemap ? reset($sitemap) : FALSE;
}

/**
 * Load multiple XML sitemaps from the database.
 *
 * @param $smids
 *   An array of XML sitemap IDs, or FALSE to load all XML sitemaps.
 * @param $conditions
 *   An array of conditions in the form 'field' => $value.
 *
 * @return
 *   An array of XML sitemap objects.
 */
function xmlsitemap_sitemap_load_multiple($smids = array(), array $conditions = array()) {
  if ($smids !== FALSE) {
    $conditions['smid'] = $smids;
  }

  $query = db_select('xmlsitemap_sitemap');
  $query->fields('xmlsitemap_sitemap');
  foreach ($conditions as $field => $value) {
    $query->condition($field, $value);
  }

  $sitemaps = $query->execute()->fetchAllAssoc('smid');
  foreach ($sitemaps as $smid => $sitemap) {
    $sitemaps[$smid]->context = unserialize($sitemap->context);
    $sitemaps[$smid]->uri = xmlsitemap_sitemap_uri($sitemaps[$smid]);
  }

  return $sitemaps;
}

/**
 * Load an XML sitemap array from the database based on its context.
 *
 * @param $context
 *   An optional XML sitemap context array to use to find the correct XML
 *   sitemap. If not provided, the current site's context will be used.
 *
 * @see xmlsitemap_get_current_context()
 */
function xmlsitemap_sitemap_load_by_context(array $context = NULL) {
  if (!isset($context)) {
    $context = xmlsitemap_get_current_context();
  }
  $hash = xmlsitemap_sitemap_get_context_hash($context);
  $smid = db_query_range("SELECT smid FROM {xmlsitemap_sitemap} WHERE smid = :hash", 0, 1, array(':hash' => $hash))->fetchField();
  return xmlsitemap_sitemap_load($smid);
}

/**
 * Save changes to an XML sitemap or add a new XML sitemap.
 *
 * @param $sitemap
 *   The XML sitemap array to be saved. If $sitemap->smid is omitted, a new
 *   XML sitemap will be added.
 *
 * @todo Save the sitemap's URL as a column?
 */
function xmlsitemap_sitemap_save(stdClass $sitemap) {
  if (!isset($sitemap->context)) {
    $sitemap->context = array();
  }

  // Make sure context is sorted before saving the hash.
  $sitemap->is_new = empty($sitemap->smid);
  $sitemap->old_smid = $sitemap->is_new ? NULL : $sitemap->smid;
  $sitemap->smid = xmlsitemap_sitemap_get_context_hash($sitemap->context);

  // If the context was changed, we need to perform additional actions.
  if (!$sitemap->is_new && $sitemap->smid != $sitemap->old_smid) {
    // Rename the files directory so the sitemap does not break.
    $old_sitemap = (object) array('smid' => $sitemap->old_smid);
    $old_dir = xmlsitemap_get_directory($old_sitemap);
    $new_dir = xmlsitemap_get_directory($sitemap);
    xmlsitemap_directory_move($old_dir, $new_dir);

    // Change the smid field so drupal_write_record() does not fail.
    db_update('xmlsitemap_sitemap')
      ->fields(array('smid' => $sitemap->smid))
      ->condition('smid', $sitemap->old_smid)
      ->execute();

    // Mark the sitemaps as needing regeneration.
    variable_set('xmlsitemap_regenerate_needed', TRUE);
  }

  if ($sitemap->is_new) {
    drupal_write_record('xmlsitemap_sitemap', $sitemap);
    module_invoke_all('xmlsitemap_sitemap_insert', $sitemap);
  }
  else {
    drupal_write_record('xmlsitemap_sitemap', $sitemap, array('smid'));
    module_invoke_all('xmlsitemap_sitemap_update', $sitemap);
  }

  return $sitemap;
}

/**
 * Delete an XML sitemap.
 *
 * @param $smid
 *   An XML sitemap ID.
 */
function xmlsitemap_sitemap_delete($smid) {
  xmlsitemap_sitemap_delete_multiple(array($smid));
}

/**
 * Delete multiple XML sitemaps.
 *
 * @param $smids
 *   An array of XML sitemap IDs.
 */
function xmlsitemap_sitemap_delete_multiple(array $smids) {
  if (!empty($smids)) {
    $sitemaps = xmlsitemap_sitemap_load_multiple($smids);
    db_delete('xmlsitemap_sitemap')
        ->condition('smid', $smids)
        ->execute();

    foreach ($sitemaps as $sitemap) {
      xmlsitemap_clear_directory($sitemap, TRUE);
      module_invoke_all('xmlsitemap_sitemap_delete', $sitemap);
    }
  }
}

/**
 * Return the expected file path for a specific sitemap chunk.
 *
 * @param $sitemap
 *   An XML sitemap array.
 * @param $chunk
 *   An optional specific chunk in the sitemap. Defaults to the index page.
 */
function xmlsitemap_sitemap_get_file(stdClass $sitemap, $chunk = 'index') {
  return xmlsitemap_get_directory($sitemap) . "/{$chunk}.xml";
}

/**
 * Find the maximum file size of all a sitemap's XML files.
 *
 * @param $sitemap
 *   The XML sitemap array.
 */
function xmlsitemap_sitemap_get_max_filesize(stdClass $sitemap) {
  $dir = xmlsitemap_get_directory($sitemap);
  $sitemap->max_filesize = 0;
  foreach (file_scan_directory($dir, '/\.xml$/') as $file) {
    $sitemap->max_filesize = max($sitemap->max_filesize, filesize($file->uri));
  }
  return $sitemap->max_filesize;
}

function xmlsitemap_sitemap_get_context_hash(array &$context) {
  asort($context);
  return drupal_hash_base64(serialize($context));
}

/**
 * Returns the uri elements of an XML sitemap.
 *
 * @param $sitemap
 *   An unserialized data array for an XML sitemap.
 * @return
 *   An array containing the 'path' and 'options' keys used to build the uri of
 *   the XML sitemap, and matching the signature of url().
 */
function xmlsitemap_sitemap_uri(stdClass $sitemap) {
  $uri['path'] = 'sitemap.xml';
  $uri['options'] = module_invoke_all('xmlsitemap_context_url_options', $sitemap->context);
  drupal_alter('xmlsitemap_context_url_options', $uri['options'], $sitemap->context);
  $uri['options'] += array(
    'absolute' => TRUE,
    'base_url' => variable_get('xmlsitemap_base_url', $GLOBALS['base_url']),
  );
  return $uri;
}

/**
 * Load a specific sitemap link from the database.
 *
 * @param $entity_type
 *   A string with the entity type.
 * @param $entity_id
 *   An integer with the entity ID.
 * @return
 *   A sitemap link (array) or FALSE if the conditions were not found.
 */
function xmlsitemap_link_load($entity_type, $entity_id) {
  $link = xmlsitemap_link_load_multiple(array('type' => $entity_type, 'id' => $entity_id));
  return $link ? reset($link) : FALSE;
}

/**
 * Load sitemap links from the database.
 *
 * @param $conditions
 *   An array of conditions on the {xmlsitemap} table in the form
 *   'field' => $value.
 * @return
 *   An array of sitemap link arrays.
 */
function xmlsitemap_link_load_multiple(array $conditions = array()) {
  $query = db_select('xmlsitemap');
  $query->fields('xmlsitemap');

  foreach ($conditions as $field => $value) {
    $query->condition($field, $value);
  }

  $links = $query->execute()->fetchAll(PDO::FETCH_ASSOC);

  return $links;
}

/**
 * Saves or updates a sitemap link.
 *
 * @param $link
 *   An array with a sitemap link.
 */
function xmlsitemap_link_save(array $link) {
  $link += array(
    'access' => 1,
    'status' => 1,
    'status_override' => 0,
    'lastmod' => 0,
    'priority' => XMLSITEMAP_PRIORITY_DEFAULT,
    'priority_override' => 0,
    'changefreq' => 0,
    'changecount' => 0,
    'language' => LANGUAGE_NONE,
  );

  // Allow other modules to alter the link before saving.
  drupal_alter('xmlsitemap_link', $link);

  // Temporary validation checks.
  // @todo Remove in final?
  if ($link['priority'] < 0 || $link['priority'] > 1) {
    trigger_error(t('Invalid sitemap link priority %priority.<br />@link', array('%priority' => $link['priority'], '@link' => var_export($link, TRUE))), E_USER_ERROR);
  }
  if ($link['changecount'] < 0) {
    trigger_error(t('Negative changecount value. Please report this to <a href="@516928">@516928</a>.<br />@link', array('@516928' => 'http://drupal.org/node/516928', '@link' => var_export($link, TRUE))), E_USER_ERROR);
    $link['changecount'] = 0;
  }

  $existing = db_query_range("SELECT loc, access, status, lastmod, priority, changefreq, changecount, language FROM {xmlsitemap} WHERE type = :type AND id = :id", 0, 1, array(':type' => $link['type'], ':id' => $link['id']))->fetchAssoc();

  // Check if this is a changed link and set the regenerate flag if necessary.
  if (!variable_get('xmlsitemap_regenerate_needed', FALSE)) {
    _xmlsitemap_check_changed_link($link, $existing, TRUE);
  }

  if ($existing) {
    drupal_write_record('xmlsitemap', $link, array('type', 'id'));
  }
  else {
    drupal_write_record('xmlsitemap', $link);
  }

  // Allow other modules to respond after saving the link.
  //module_invoke_all('xmlsitemap_save_link', $link);

  return $link;
}

/**
 * Perform a mass update of sitemap data.
 *
 * If visible links are updated, this will automatically set the regenerate
 * needed flag to TRUE.
 *
 * @param $updates
 *   An array of values to update fields to, keyed by field name.
 * @param $conditions
 *   An array of values to match keyed by field.
 * @return
 *   The number of links that were updated.
 */
function xmlsitemap_link_update_multiple($updates = array(), $conditions = array(), $check_flag = TRUE) {
  // If we are going to modify a visible sitemap link, we will need to set
  // the regenerate needed flag.
  if ($check_flag && !variable_get('xmlsitemap_regenerate_needed', FALSE)) {
    _xmlsitemap_check_changed_links($conditions, $updates, TRUE);
  }

  // Process updates.
  $query = db_update('xmlsitemap');
  $query->fields($updates);
  foreach ($conditions as $field => $value) {
    $query->condition($field, $value);
  }

  return $query->execute();
}

/**
 * Delete a specific sitemap link from the database.
 *
 * If a visible sitemap link was deleted, this will automatically set the
 * regenerate needed flag.
 *
 * @param $entity_type
 *   A string with the entity type.
 * @param $entity_id
 *   An integer with the entity ID.
 * @return
 *   The number of links that were deleted.
 */
function xmlsitemap_link_delete($entity_type, $entity_id) {
  $conditions = array('type' => $entity_type, 'id' => $entity_id);
  return xmlsitemap_link_delete_multiple($conditions);
}

/**
 * Delete multiple sitemap links from the database.
 *
 * If visible sitemap links were deleted, this will automatically set the
 * regenerate needed flag.
 *
 * @param $conditions
 *   An array of conditions on the {xmlsitemap} table in the form
 *   'field' => $value.
 * @return
 *   The number of links that were deleted.
 */
function xmlsitemap_link_delete_multiple(array $conditions) {
  // Because this function is called from sub-module uninstall hooks, we have
  // to manually check if the table exists since it could have been removed
  // in xmlsitemap_uninstall().
  // @todo Remove this check when http://drupal.org/node/151452 is fixed.
  if (!db_table_exists('xmlsitemap')) {
    return FALSE;
  }

  if (!variable_get('xmlsitemap_regenerate_needed', TRUE)) {
    _xmlsitemap_check_changed_links($conditions, array(), TRUE);
  }

  $query = db_delete('xmlsitemap');
  foreach ($conditions as $field => $value) {
    $query->condition($field, $value);
  }

  return $query->execute();
}

/**
 * Check if there is a visible sitemap link given a certain set of conditions.
 *
 * @param $conditions
 *   An array of values to match keyed by field.
 * @param $flag
 *   An optional boolean that if TRUE, will set the regenerate needed flag if
 *   there is a match. Defaults to FALSE.
 * @return
 *   TRUE if there is a visible link, or FALSE otherwise.
 */
function _xmlsitemap_check_changed_links(array $conditions = array(), array $updates = array(), $flag = FALSE) {
  // If we are changing status or access, check for negative current values.
  $conditions['status'] = (!empty($updates['status']) && empty($condition['status'])) ? 0 : 1;
  $conditions['access'] = (!empty($updates['access']) && empty($condition['access'])) ? 0 : 1;

  $query = db_select('xmlsitemap');
  $query->addExpression('1');
  foreach ($conditions as $field => $value) {
    $query->condition($field, $value);
  }
  $query->range(0, 1);
  $changed = $query->execute()->fetchField();

  if ($changed && $flag) {
    variable_set('xmlsitemap_regenerate_needed', TRUE);
  }

  return $changed;
}

/**
 * Check if there is sitemap link is changed from the existing data.
 *
 * @param $link
 *   An array of the sitemap link.
 * @param $original_link
 *   An optional array of the existing data. This should only contain the
 *   fields necessary for comparison. If not provided the existing data will be
 *   loaded from the database.
 * @param $flag
 *   An optional boolean that if TRUE, will set the regenerate needed flag if
 *   there is a match. Defaults to FALSE.
 * @return
 *   TRUE if the link is changed, or FALSE otherwise.
 */
function _xmlsitemap_check_changed_link(array $link, $original_link = NULL, $flag = FALSE) {
  $changed = FALSE;

  if ($original_link === NULL) {
    // Load only the fields necessary for data to be changed in the sitemap.
    $original_link = db_query_range("SELECT loc, access, status, lastmod, priority, changefreq, changecount, language FROM {xmlsitemap} WHERE type = :type AND id = :id", 0, 1, array(':type' => $link['type'], ':id' => $link['id']))->fetchAssoc();
  }

  if (!$original_link) {
    if ($link['access'] && $link['status']) {
      // Adding a new visible link.
      $changed = TRUE;
    }
  }
  else {
    if (!($original_link['access'] && $original_link['status']) && $link['access'] && $link['status']) {
      // Changing a non-visible link to a visible link.
      $changed = TRUE;
    }
    elseif ($original_link['access'] && $original_link['status'] && array_diff_assoc($original_link, $link)) {
      // Changing a visible link
      $changed = TRUE;
    }
  }

  if ($changed && $flag) {
    variable_set('xmlsitemap_regenerate_needed', TRUE);
  }

  return $changed;
}

/**
 * @} End of "defgroup xmlsitemap_api"
 */

function xmlsitemap_get_directory(stdClass $sitemap = NULL) {
  $directory = &drupal_static(__FUNCTION__);

  if (!isset($directory)) {
    $directory = variable_get('xmlsitemap_path', 'xmlsitemap');
  }

  if (!empty($sitemap->smid)) {
    return file_build_uri($directory . '/' . $sitemap->smid);
  }
  else {
    return file_build_uri($directory);
  }
}

/**
 * Check that the sitemap files directory exists and is writable.
 */
function xmlsitemap_check_directory(stdClass $sitemap = NULL) {
  $directory = xmlsitemap_get_directory($sitemap);
  $result = file_prepare_directory($directory, FILE_CREATE_DIRECTORY | FILE_MODIFY_PERMISSIONS);
  if (!$result) {
    watchdog('file system', 'The directory %directory does not exist or is not writable.', array('%directory' => $directory), WATCHDOG_ERROR);
  }
  return $result;
}

function xmlsitemap_check_all_directories() {
  $directories = array();

  $sitemaps = xmlsitemap_sitemap_load_multiple(FALSE);
  foreach ($sitemaps as $smid => $sitemap) {
    $directory = xmlsitemap_get_directory($sitemap);
    $directories[$directory] = $directory;
  }

  foreach ($directories as $directory) {
    $result = file_prepare_directory($directory, FILE_CREATE_DIRECTORY | FILE_MODIFY_PERMISSIONS);
    if ($result) {
      $directories[$directory] = TRUE;
    }
    else {
      $directories[$directory] = FALSE;
    }
  }

  return $directories;
}

function xmlsitemap_clear_directory(stdClass $sitemap = NULL, $delete = FALSE) {
  $directory = xmlsitemap_get_directory($sitemap);
  return _xmlsitemap_delete_recursive($directory, $delete);
}

/**
 * Move a directory to a new location.
 *
 * @param $old_dir
 *   A string specifying the filepath or URI of the original directory.
 * @param $new_dir
 *   A string specifying the filepath or URI of the new directory.
 * @param $replace
 *   Replace behavior when the destination file already exists.
 *
 * @return
 *   TRUE if the directory was moved successfully. FALSE otherwise.
 */
function xmlsitemap_directory_move($old_dir, $new_dir, $replace = FILE_EXISTS_REPLACE) {
  $success = file_prepare_directory($new_dir, FILE_CREATE_DIRECTORY | FILE_MODIFY_PERMISSIONS);

  $old_path = drupal_realpath($old_dir);
  $new_path = drupal_realpath($new_dir);
  if (!is_dir($old_path) || !is_dir($new_path) || !$success) {
    return FALSE;
  }

  $files = file_scan_directory($old_dir, '/.*/');
  foreach ($files as $file) {
    $file->uri_new = $new_dir . '/' . basename($file->filename);
    $success &= (bool) file_unmanaged_move($file->uri, $file->uri_new, $replace);
  }

  // The remove the directory.
  $success &= drupal_rmdir($old_dir);
  return $success;
}

/**
 * Recursively delete all files and folders in the specified filepath.
 *
 * This is a backport of Drupal 7's file_unmanaged_delete_recursive().
 *
 * Note that this only deletes visible files with write permission.
 *
 * @param $path
 *   A filepath relative to the Drupal root directory.
 * @param $delete_root
 *   A boolean if TRUE will delete the $path directory afterwards.
 */
function _xmlsitemap_delete_recursive($path, $delete_root = FALSE) {
  // Resolve streamwrapper URI to local path.
  $path = drupal_realpath($path);
  if (is_dir($path)) {
    $dir = dir($path);
    while (($entry = $dir->read()) !== FALSE) {
      if ($entry == '.' || $entry == '..') {
        continue;
      }
      $entry_path = $path . '/' . $entry;
      file_unmanaged_delete_recursive($entry_path, TRUE);
    }
    $dir->close();
    return $delete_root ? drupal_rmdir($path) : TRUE;
  }
  return file_unmanaged_delete($path);
}

/**
 * Returns information about supported sitemap link types.
 *
 * @param $type
 *   (optional) The link type to return information for. If omitted,
 *   information for all link types is returned.
 * @param $reset
 *   (optional) Boolean whether to reset the static cache and do nothing. Only
 *   used for tests.
 *
 * @see hook_xmlsitemap_link_info()
 * @see hook_xmlsitemap_link_info_alter()
 */
function xmlsitemap_get_link_info($type = NULL, $reset = FALSE) {
  global $language;
  $link_info = &drupal_static(__FUNCTION__);

  if ($reset) {
    $link_info = NULL;
    entity_info_cache_clear();
  }
  elseif ($cached = cache_get('xmlsitemap:link_info:' . $language->language)) {
    $link_info = $cached->data;
  }

  if (!isset($link_info)) {
    $link_info = entity_get_info();
    foreach ($link_info as $key => $info) {
      if (empty($info['uri callback']) || !isset($info['xmlsitemap'])) {
        // Remove any non URL-able or XML sitemap un-supported entites.
        unset($link_info[$key]);
      }
      foreach ($info['bundles'] as $bundle_key => $bundle) {
        if (!isset($bundle['xmlsitemap'])) {
          // Remove any un-supported entity bundles.
          //unset($link_info[$key]['bundles'][$bundle_key]);
        }
      }
    }
    $link_info = array_merge($link_info, module_invoke_all('xmlsitemap_link_info'));
    foreach ($link_info as $key => &$info) {
      $info += array(
        'type' => $key,
        'base table' => FALSE,
        'bundles' => array(),
        'xmlsitemap' => array(),
      );
      if (!isset($info['xmlsitemap']['rebuild callback']) && !empty($info['base table']) && !empty($info['entity keys']['id']) && !empty($info['xmlsitemap']['process callback'])) {
        $info['xmlsitemap']['rebuild callback'] = 'xmlsitemap_rebuild_batch_fetch';
      }
      foreach ($info['bundles'] as $bundle => &$bundle_info) {
        $bundle_info += array(
          'xmlsitemap' => array(),
        );
        $bundle_info['xmlsitemap'] += xmlsitemap_link_bundle_load($key, $bundle, FALSE);
      }
    }
    drupal_alter('xmlsitemap_link_info', $link_info);
    ksort($link_info);
    // Cache by language since this info contains translated strings.
    cache_set('xmlsitemap:link_info:' . $language->language, $link_info);
  }

  if (isset($type)) {
    return isset($link_info[$type]) ? $link_info[$type] : NULL;
  }

  return $link_info;
}

function xmlsitemap_get_link_type_enabled_bundles($entity_type) {
  $bundles = array();
  $info = xmlsitemap_get_link_info($entity_type);
  foreach ($info['bundles'] as $bundle => $bundle_info) {
    $settings = xmlsitemap_link_bundle_load($entity_type, $bundle);
    if (!empty($settings['status'])) {
    //if (!empty($bundle_info['xmlsitemap']['status'])) {
      $bundles[] = $bundle;
    }
  }
  return $bundles;
}

function xmlsitemap_get_link_type_indexed_status($entity_type, $bundle = '') {
  $info = xmlsitemap_get_link_info($entity_type);

  $status['indexed'] = db_query("SELECT COUNT(id) FROM {xmlsitemap} WHERE type = :entity AND subtype = :bundle", array(':entity' => $entity_type, ':bundle' => $bundle))->fetchField();
  $status['visible'] = db_query("SELECT COUNT(id) FROM {xmlsitemap} WHERE type = :entity AND subtype = :bundle AND status = 1 AND access = 1", array(':entity' => $entity_type, ':bundle' => $bundle))->fetchField();

  $total = new EntityFieldQuery();
  $total->entityCondition('entity_type', $entity_type);
  $total->entityCondition('bundle', $bundle);
  $total->entityCondition('entity_id', 0, '>');
  //$total->addTag('xmlsitemap_link_bundle_access');
  $total->addTag('xmlsitemap_link_indexed_status');
  $total->addMetaData('entity', $entity_type);
  $total->addMetaData('bundle', $bundle);
  $total->addMetaData('entity_info', $info);
  $total->count();
  $status['total'] = $total->execute();

  return $status;
}

/**
 * Implements hook_entity_query_alter().
 *
 * @todo Remove when http://drupal.org/node/1054168 is fixed.
 */
function xmlsitemap_entity_query_alter($query) {
  $conditions = &$query->entityConditions;

  // Alter user entity queries only.
  if (isset($conditions['entity_type']) && $conditions['entity_type']['value'] == 'user' && isset($conditions['bundle'])) {
    unset($conditions['bundle']);
  }
}

function xmlsitemap_link_bundle_settings_save($entity, $bundle, array $settings, $update_links = TRUE) {
  if ($update_links) {
    $old_settings = xmlsitemap_link_bundle_load($entity, $bundle);
    if ($settings['status'] != $old_settings['status']) {
      xmlsitemap_link_update_multiple(array('status' => $settings['status']), array('type' => $entity, 'subtype' => $bundle, 'status_override' => 0));
    }
    if ($settings['priority'] != $old_settings['priority']) {
      xmlsitemap_link_update_multiple(array('priority' => $settings['priority']), array('type' => $entity, 'subtype' => $bundle, 'priority_override' => 0));
    }
  }

  variable_set("xmlsitemap_settings_{$entity}_{$bundle}", $settings);
  cache_clear_all('xmlsitemap:link_info:', 'cache', TRUE);
  //xmlsitemap_get_link_info(NULL, TRUE);
}

function xmlsitemap_link_bundle_rename($entity, $bundle_old, $bundle_new) {
  if ($bundle_old != $bundle_new) {
    $settings = xmlsitemap_link_bundle_load($entity, $bundle_old);
    variable_del("xmlsitemap_settings_{$entity}_{$bundle_old}");
    xmlsitemap_link_bundle_settings_save($entity, $bundle_new, $settings, FALSE);
    xmlsitemap_link_update_multiple(array('subtype' => $bundle_new), array('type' => $entity, 'subtype' => $bundle_old));
  }
}

/**
 * Rename a link type.
 */
function xmlsitemap_link_type_rename($entity_old, $entity_new, $bundles = NULL) {
  $variables = db_query("SELECT name FROM {variable} WHERE name LIKE :pattern", array(':pattern' => db_like('xmlsitemap_settings_' . $entity_old . '_') . '%'))->fetchCol();
  foreach ($variables as $variable) {
    $value = variable_get($variable);
    variable_del($variable);
    if (isset($value)) {
      $variable_new = str_replace($entity_old, $entity_new, $variable);
      variable_set($variable_new, $value);
    }
  }

  xmlsitemap_link_update_multiple(array('type' => $entity_new), array('type' => $entity_old), FALSE);
  xmlsitemap_get_link_info(NULL, TRUE);
}

function xmlsitemap_link_bundle_load($entity, $bundle, $load_bundle_info = TRUE) {
  $info = array(
    'entity' => $entity,
    'bundle' => $bundle,
  );
  if ($load_bundle_info) {
    $entity_info = xmlsitemap_get_link_info($entity);
    if (isset($entity_info['bundles'][$bundle])) {
      $info['info'] = $entity_info['bundles'][$bundle];
    }
  }
  $info += variable_get("xmlsitemap_settings_{$entity}_{$bundle}", array());
  $info += array(
    'status' => XMLSITEMAP_STATUS_DEFAULT,
    'priority' => XMLSITEMAP_PRIORITY_DEFAULT,
  );
  return $info;
}

function xmlsitemap_link_bundle_delete($entity, $bundle, $delete_links = TRUE) {
  variable_del("xmlsitemap_settings_{$entity}_{$bundle}");
  if ($delete_links) {
    xmlsitemap_link_delete_multiple(array('type' => $entity, 'subtype' => $bundle));
  }
  cache_clear_all('xmlsitemap:link_info:', 'cache', TRUE);
  //xmlsitemap_get_link_info(NULL, TRUE);
}

function xmlsitemap_link_bundle_access($entity, $bundle = NULL) {
  if (is_array($entity) && !isset($bundle)) {
    $bundle = $entity;
  }
  else {
    $bundle = xmlsitemap_link_bundle_load($entity, $bundle);
  }

  if (isset($bundle['info']['admin'])) {
    $admin = $bundle['info']['admin'];
    $admin += array('access arguments' => array());

    if (!isset($admin['access callback']) && count($admin['access arguments']) == 1) {
      $admin['access callback'] = 'user_access';
    }

    if (!empty($admin['access callback'])) {
      return call_user_func_array($admin['access callback'], $admin['access arguments']);
    }
  }

  return FALSE;
}

function xmlsitemap_get_bundle_path($entity, $bundle) {
  $info = xmlsitemap_get_link_info($entity);

  if (!empty($info['bundles'][$bundle]['admin']['real path'])) {
    return $info['bundles'][$bundle]['admin']['real path'];
  }
  elseif (!empty($info['bundles'][$bundle]['admin']['path'])) {
    return $info['bundles'][$bundle]['admin']['path'];
  }
  else {
    return FALSE;
  }
}

/**
 * Implements hook_field_attach_rename_bundle().
 */
function xmlsitemap_field_attach_rename_bundle($entity_type, $bundle_old, $bundle_new) {
  xmlsitemap_link_bundle_rename($entity_type, $bundle_old, $bundle_new);
}

/**
 * Implements hook_field_attach_delete_bundle().
 */
function xmlsitemap_field_attach_delete_bundle($entity_type, $bundle, $instances) {
  xmlsitemap_link_bundle_delete($entity_type, $bundle, TRUE);
}

/**
 * Determine the frequency of updates to a link.
 *
 * @param $interval
 *   An interval value in seconds.
 * @return
 *   A string representing the update frequency according to the sitemaps.org
 *   protocol.
 */
function xmlsitemap_get_changefreq($interval) {
  if ($interval <= 0 || !is_numeric($interval)) {
    return FALSE;
  }

  foreach (xmlsitemap_get_changefreq_options() as $value => $frequency) {
    if ($interval <= $value) {
      return $frequency;
    }
  }

  return 'never';
}

/**
 * Get the current number of sitemap chunks.
 */
function xmlsitemap_get_chunk_count($reset = FALSE) {
  static $chunks;
  if (!isset($chunks) || $reset) {
    $count = max(xmlsitemap_get_link_count($reset), 1);
    $chunks = ceil($count / xmlsitemap_get_chunk_size($reset));
  }
  return $chunks;
}

/**
 * Get the current number of sitemap links.
 */
function xmlsitemap_get_link_count($reset = FALSE) {
  static $count;
  if (!isset($count) || $reset) {
    $count = db_query("SELECT COUNT(id) FROM {xmlsitemap} WHERE access = 1 AND status = 1")->fetchField();
  }
  return $count;
}

/**
 * Get the sitemap chunk size.
 *
 * This function is useful with the chunk size is set to automatic as it will
 * calculate the appropriate value. Use this function instead of @code
 * xmlsitemap_var('chunk_size') @endcode when the actual value is needed.
 *
 * @param $reset
 *   A boolean to reset the saved, static result. Defaults to FALSE.
 * @return
 *   An integer with the number of links in each sitemap page.
 */
function xmlsitemap_get_chunk_size($reset = FALSE) {
  static $size;
  if (!isset($size) || $reset) {
    $size = xmlsitemap_var('chunk_size');
    if ($size === 'auto') {
      $count = max(xmlsitemap_get_link_count($reset), 1); // Prevent divide by zero.
      $size = min(ceil($count / 10000) * 5000, XMLSITEMAP_MAX_SITEMAP_LINKS);
    }
  }
  return $size;
}

/**
 * Recalculate the changefreq of a sitemap link.
 *
 * @param $link
 *   A sitemap link array.
 */
function xmlsitemap_recalculate_changefreq(&$link) {
  $link['changefreq'] = round((($link['changefreq'] * $link['changecount']) + (REQUEST_TIME - $link['lastmod'])) / ($link['changecount'] + 1));
  $link['changecount']++;
  $link['lastmod'] = REQUEST_TIME;
}

/**
 * Calculates the average interval between UNIX timestamps.
 *
 * @param $timestamps
 *   An array of UNIX timestamp integers.
 * @return
 *   An integer of the average interval.
 */
function xmlsitemap_calculate_changefreq($timestamps) {
  sort($timestamps);
  $count = count($timestamps) - 1;
  $diff = 0;

  for ($i = 0; $i < $count; $i++) {
    $diff += $timestamps[$i + 1] - $timestamps[$i];
  }

  return $count > 0 ? round($diff / $count) : 0;
}

/**
 * Submit handler; Set the regenerate needed flag if variables have changed.
 *
 * This function needs to be called before system_settings_form_submit() or any
 * calls to variable_set().
 */
function xmlsitemap_form_submit_flag_regenerate($form, $form_state) {
  foreach ($form_state['values'] as $variable => $value) {
    $stored_value = variable_get($variable, 'not_a_variable');
    if (is_array($value) && !empty($form_state['values']['array_filter'])) {
      $value = array_keys(array_filter($value));
    }
    if ($stored_value != 'not_a_variable' && $stored_value != $value) {
      variable_set('xmlsitemap_regenerate_needed', TRUE);
      drupal_set_message(t('XML sitemap settings have been modified and the files should be regenerated. You can <a href="@run-cron">run cron manually</a> to regenerate the cached files.', array('@run-cron' => url('admin/reports/status/run-cron', array('query' => drupal_get_destination())))), 'warning', FALSE);
      return;
    }
  }
}

/**
 * Set the current user stored in $GLOBALS['user'].
 *
 * @todo Remove when http://drupal.org/node/287292 is fixed.
 */
function xmlsitemap_switch_user($new_user = NULL) {
  global $user;
  $user_original = &drupal_static(__FUNCTION__);

  if (!isset($new_user)) {
    if (isset($user_original)) {
      // Restore the original user.
      $user = $user_original;
      $user_original = NULL;
      drupal_save_session(TRUE);
    }
    else {
      return FALSE;
    }
  }
  elseif (is_numeric($new_user) && $user->uid != $new_user) {
    // Get the full user object.
    if (!$new_user) {
      $new_user = drupal_anonymous_user();
    }
    elseif (!$new_user = user_load($new_user)) {
      return FALSE;
    }

    // Backup the original user object.
    if (!isset($user_original)) {
      $user_original = $user;
      drupal_save_session(FALSE);
    }

    $user = $new_user;
  }
  elseif (is_object($new_user) && $user->uid != $new_user->uid) {
    // Backup the original user object.
    if (!isset($user_original)) {
      $user_original = $user;
      drupal_save_session(FALSE);
    }

    $user = $new_user;
  }
  else {
    return FALSE;
  }

  return $user;
}

/**
 * Restore the user that was originally loaded.
 *
 * @return
 *  Current user.
 */
function xmlsitemap_restore_user() {
  return xmlsitemap_switch_user();
}

function xmlsitemap_process_form_link_options($form, &$form_state) {
  $link = &$form_state['values']['xmlsitemap'];
  $fields = array('status' => XMLSITEMAP_STATUS_DEFAULT, 'priority' => XMLSITEMAP_PRIORITY_DEFAULT);

  foreach ($fields as $field => $default) {
    if ($link[$field] === 'default') {
      $link[$field] = isset($link[$field . '_default']) ? $link[$field . '_default'] : $default;
      $link[$field . '_override'] = 0;
    }
    else {
      $link[$field . '_override'] = 1;
    }
  }
}

function xmlsitemap_link_bundle_settings_form_submit($form, &$form_state) {
  $entity = $form['xmlsitemap']['#entity'];
  $bundle = $form['xmlsitemap']['#bundle'];

  // Handle new bundles by fetching the proper bundle key value from the form
  // state values.
  if (empty($bundle)) {
    $entity_info = $form['xmlsitemap']['#entity_info'];
    if (isset($entity_info['bundle keys']['bundle'])) {
      $bundle_key = $entity_info['bundle keys']['bundle'];
      if (isset($form_state['values'][$bundle_key])) {
        $bundle = $form_state['values'][$bundle_key];
        $form['xmlsitemap']['#bundle'] = $bundle;
      }
    }
  }

  xmlsitemap_link_bundle_settings_save($entity, $bundle, $form_state['values']['xmlsitemap']);

  $entity_info = $form['xmlsitemap']['#entity_info'];
  if (!empty($form['xmlsitemap']['#show_message'])) {
    drupal_set_message(t('XML sitemap settings for the @bundle-label %bundle have been saved.', array('@bundle-label' => drupal_strtolower($entity_info['bundle label']), '%bundle' => $entity_info['bundles'][$bundle]['label'])));
  }

  // Unset the form values since we have already saved the bundle settings and
  // we don't want these values to get saved as variables in-case this form
  // also uses system_settings_form().
  unset($form_state['values']['xmlsitemap']);
}

/**
 * @todo Document this function.
 * @todo Make these translatable
 */
function xmlsitemap_get_changefreq_options() {
  return array(
    XMLSITEMAP_FREQUENCY_ALWAYS => 'always',
    XMLSITEMAP_FREQUENCY_HOURLY => 'hourly',
    XMLSITEMAP_FREQUENCY_DAILY => 'daily',
    XMLSITEMAP_FREQUENCY_WEEKLY => 'weekly',
    XMLSITEMAP_FREQUENCY_MONTHLY => 'monthly',
    XMLSITEMAP_FREQUENCY_YEARLY => 'yearly',
  );
}

/**
 * Load a language object by its language code.
 *
 * @todo Remove when http://drupal.org/node/660736 is fixed in Drupal core.
 *
 * @param $language
 *   A language code. If not provided the default language will be returned.
 * @return
 *   A language object.
 */
function xmlsitemap_language_load($language = LANGUAGE_NONE) {
  $languages = &drupal_static(__FUNCTION__);

  if (!isset($languages)) {
    $languages = language_list();
    $languages[LANGUAGE_NONE] = NULL;
  }

  return isset($languages[$language]) ? $languages[$language] : NULL;
}

/**
 * @defgroup xmlsitemap_context_api XML sitemap API for sitemap contexts.
 * @{
 */

function xmlsitemap_get_context_info($context = NULL, $reset = FALSE) {
  global $language;
  $info = &drupal_static(__FUNCTION__);

  if ($reset) {
    $info = NULL;
  }
  elseif ($cached = cache_get('xmlsitemap:context_info:' . $language->language)) {
    $info = $cached->data;
  }

  if (!isset($info)) {
    $info = module_invoke_all('xmlsitemap_context_info');
    drupal_alter('xmlsitemap_context_info', $info);
    ksort($info);
    // Cache by language since this info contains translated strings.
    cache_set('xmlsitemap:context_info:' . $language->language, $info);
  }

  if (isset($context)) {
    return isset($info[$context]) ? $info[$context] : NULL;
  }

  return $info;
}

/**
 * Get the sitemap context of the current request.
 */
function xmlsitemap_get_current_context() {
  $context = &drupal_static(__FUNCTION__);

  if (!isset($context)) {
    $context = module_invoke_all('xmlsitemap_context');
    drupal_alter('xmlsitemap_context', $context);
    asort($context);
  }

  return $context;
}

function _xmlsitemap_sitemap_context_summary(stdClass $sitemap, $context_key, array $context_info) {
  $context_value = isset($sitemap->context[$context_key]) ? $sitemap->context[$context_key] : NULL;

  if (!isset($context_value)) {
    return t('Default');
  }
  elseif (!empty($context_info['summary callback'])) {
    return $context_info['summary callback']($context_value);
  }
  else {
    return $context_value;
  }
}

/**
 * @} End of "defgroup xmlsitemap_context_api"
 */

/**
 * Run a not-progressive batch operation.
 */
function xmlsitemap_run_unprogressive_batch() {
  $batch = batch_get();
  if (!empty($batch)) {
    // If there is already something in the batch, don't run.
    return FALSE;
  }

  $args = func_get_args();
  $batch_callback = array_shift($args);

  if (!lock_acquire($batch_callback)) {
    return FALSE;
  }

  // Attempt to increase the execution time.
  drupal_set_time_limit(240);

  // Build the batch array.
  $batch = call_user_func_array($batch_callback, $args);
  batch_set($batch);

  // We need to manually set the progressive variable again.
  // @todo Remove when http://drupal.org/node/638712 is fixed.
  $batch =& batch_get();
  $batch['progressive'] = FALSE;

  // Run the batch process.
  batch_process();

  lock_release($batch_callback);
  return TRUE;
}

/**
 * Workaround for missing breadcrumbs on callback and action paths.
 *
 * @todo Remove when http://drupal.org/node/576290 is fixed.
 */
function _xmlsitemap_set_breadcrumb($path = 'admin/config/search/xmlsitemap') {
  $breadcrumb = array();
  $path = explode('/', $path);
  do {
    $menu_path = implode('/', $path);
    $menu_item = menu_get_item($menu_path);
    array_unshift($breadcrumb, l($menu_item['title'], $menu_path));
  } while (array_pop($path) && !empty($path));
  array_unshift($breadcrumb, l(t('Home'), NULL));
  drupal_set_breadcrumb($breadcrumb);
}

function xmlsitemap_get_operation_link($url, $options = array()) {
  static $destination;

  if (!isset($destination)) {
    $destination = drupal_get_destination();
  }

  $link = array('href' => $url) + $options;

  // Fetch the item's menu router link info and title.
  if (!isset($link['title'])) {
    $item = menu_get_item($url);
    $link['title'] = $item['title'];
  }

  $link += array('query' => $destination);
  return $link;
}