*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

*   http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing,

* software distributed under the License is distributed on an

* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

* KIND, either express or implied.  See the License for the

* specific language governing permissions and limitations

* under the License.

*

*/

* Migration Helper

*

* This class provides helper methods for migrating from earlier versions of Wookie.

*

* Note that this class and/or its methods may be deprecated in future releases.

*/

 

  static Logger _logger = Logger.getLogger(MigrationHelper.class.getName());

  /**

   * Finds a widget instance using supplied parameters, using legacy shared data key generation methods. If an instance

   * is found, the instance and any related resources are updated to use the current generation methods.

   * @param apiKey

   * @param userId

   * @param sharedDataKey the shared data key, in its original external form

   * @param widgetId

   * @param serviceType

   * @return the widget instance, or null if there is no match

   * @throws UnsupportedEncodingException

   */

  public static IWidgetInstance findLegacyWidgetInstance(String apiKey, String userId, String sharedDataKey, String widgetId) throws UnsupportedEncodingException{

    //

    // Get shared data key using legacy method

    //

    String legacySharedDataKey = getLegacySharedDataKey(sharedDataKey);

    //

    // Find widget instance

    //

    IWidgetInstance instance = WidgetInstancesController.findWidgetInstance(apiKey, userId, legacySharedDataKey, widgetId);

    //

    // Match found, so migrate the instance as well as any sibling instances that use the same shared data key, and any shared data instances

    //

    if (instance != null){ 

      //

      // Get shared data key using current method

      //

      String internalSharedDataKey = SharedDataHelper.getInternalSharedDataKey(apiKey, widgetId, sharedDataKey);

      //

      // migrate instances and shared data using the legacy key to use new shared data hashcodes

      //

      migrateSharedDataKeys(legacySharedDataKey, internalSharedDataKey);

    }

    return instance;

  }

  /**

   * Get the legacy version of the shared data key, from 0.9.0

   *

   * @param externalSharedDataKey

   * @return the legacy shared data key as a String

   */

  private static String getLegacySharedDataKey(String externalSharedDataKey){

    String key = "null:"+externalSharedDataKey;

    return String.valueOf(key.hashCode());

  }

  /**

   * Migrate objects based on shared data keys

   *

   * @param oldKey the old legacy shared data key

   * @param newKey the new key to use as replacement

   */

  private static void migrateSharedDataKeys(String oldKey, String newKey){

    //

    // Locate instances using the old key and migrate to the new key

    //

    IPersistenceManager persistenceManager = PersistenceManagerFactory.getPersistenceManager();

    IWidgetInstance[] widgetInstances = persistenceManager.findByValue(IWidgetInstance.class, "sharedDataKey", oldKey);

    for (IWidgetInstance widgetInstance:widgetInstances){

      widgetInstance.setSharedDataKey(newKey);

      persistenceManager.save(widgetInstance);

    }

    //

    // locate shared data objects using the old key and migrate to the new key

    //

    ISharedData[] sharedDataItems = persistenceManager.findByValue(ISharedData.class, "sharedDataKey", oldKey);

    for (ISharedData sharedData: sharedDataItems){

      sharedData.setSharedDataKey(newKey);

      persistenceManager.save(sharedData);

    }

   

    _logger.debug("upgraded widget instances and shared data from 0.9.0. Old key:"+oldKey+" . New key:"+newKey+". "+widgetInstances.length+" widget instances  and "+sharedDataItems.length+" shared data objects updated.");

  }

}