<?php

/**
 * @file
 * UUID path module functions.
 */

/**
 * Implements hook_entity_uuid_load().
 */
function uuid_path_entity_uuid_load(&$entities, $entity_type) {
  _uuid_path_load_url_aliases($entities, $entity_type);
}

/**
 * Implements hook_entity_uuid_save().
 */
function uuid_path_entity_uuid_save(&$entity, $entity_type) {
  _uuid_path_save_url_aliases($entity, $entity_type);
}

/**
 * Loads url aliases in the corresponding entity.
 */
function _uuid_path_load_url_aliases(&$entities, $entity_type) {
  $info = entity_get_info($entity_type);
  // We only care about entities with URLs.
  if (!isset($info['uri callback'])) {
    return;
  }

  $callback = $info['uri callback'];
  foreach ($entities as $id => $entity) {
    $path = $callback($entity);
    $aliases = _uuid_path_url_alias_load($path['path']);

    // Ignore local IDs.
    foreach ($aliases as &$alias) {
      unset($alias->pid);
      unset($alias->source);
    }

    $entities[$id]->url_alias = $aliases;
  }
}

/**
 * Saves the received url aliases.
 */
function _uuid_path_save_url_aliases(&$entity, $entity_type) {
  $info = entity_get_info($entity_type);

  // We only care when there is a url callback.
  if (!isset($info['uri callback'])) {
    return FALSE;
  }

  $callback = $info['uri callback'];
  $uri = $callback($entity);
  $path = $uri['path'];

  // Delete existing aliases.
  path_delete(array('source' => $path));

  // Continue if aliases are present.
  if (empty($entity->url_alias)) {
    return FALSE;
  }

  foreach ($entity->url_alias as $alias) {
    $entry = (array) $alias;
    $entry['source'] = $path;
    path_save($entry);
  }
}

/**
 * Loads all aliases associated with a path.
 *
 * @param string $path
 *   The source path to look up.
 *
 * @return array
 *   Array of paths or NULL if none found.
 */
function _uuid_path_url_alias_load($path) {
  return db_select('url_alias')
    ->condition('source', $path)
    ->fields('url_alias')
    ->execute()
    ->fetchAll(PDO::FETCH_OBJ);
}