/**
    * Copyright 2005-2014 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.
   */
  package org.kuali.rice.krad.util;
  
  import org.kuali.rice.kew.api.KewApiServiceLocator;
  import org.kuali.rice.krad.UserSession;
  import org.kuali.rice.krad.data.KradDataServiceLocator;
  import org.kuali.rice.krad.datadictionary.DocumentEntry;
  import org.kuali.rice.krad.service.KRADServiceLocatorWeb;
  
  import java.util.concurrent.Callable;
  
  /**
   * Exposes legacy detection functionality statically.
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public final class LegacyUtils {
  
      private static LegacyDetector ld = new LegacyDetector(KradDataServiceLocator.getMetadataRepository(),
              KRADServiceLocatorWeb.getDataDictionaryService());
  
      private LegacyUtils() {
          throw new UnsupportedOperationException(LegacyUtils.class + " should not be constructed");
      }
  
      /**
       * Indicates whether the given type is managed by the legacy data framework. Note that it's possible for a given
       * type to managed by both the legacy and the non-legacy data framework, in which case this method will return true
       * as well.
       *
       * @param type the type to check
       * @return true if managed by the legacy framework, false otherwise
       */
      public static boolean isLegacyManaged(Class<?> type) {
          return ld.isLegacyManaged(type);
      }
  
      /**
       * Indicates whether the given type is managed by the non-legacy data framework. Note that it's possible for a given
       * type to managed by both the legacy and the non-legacy data framework, in which case this method will return true
       * as well.
       *
       * @param type the type to check
       * @return true if managed by the non-legacy krad-data framework, false otherwise
       */
      public static boolean isKradDataManaged(Class<?> type) {
          return ld.isKradDataManaged(type);
      }
  
      /**
       * Indicates whether or not the given DocumentEntry represents a legacy KNS document entry.
       *
       * @param documentEntry the document entry to check
       * @return true if the given entry is a KNS entry, false otherwise
       */
      public static boolean isKnsDocumentEntry(DocumentEntry documentEntry) {
          return "org.kuali.rice.kns.datadictionary".equals(documentEntry.getClass().getPackage().getName());
      }
  
      public static boolean isKnsEnabled() {
          return ld.isKnsEnabled();
      }
  
      /**
       * Return whether the legacy data framework is enabled
       * @return whether the legacy data framework is enabled
       */
      public static boolean isLegacyDataFrameworkEnabled() {
          return ld.isLegacyDataFrameworkEnabled();
      }
  
      /**
       * Return whether objects of the given class should be handled via the legacy data framework
       * @param dataObjectClass the data object class
       * @return whether objects of the given class should be handled via the legacy data framework
       */
      public static boolean useLegacy(Class<?> dataObjectClass) {
          return ld.useLegacy(dataObjectClass);
      }
  
      /**
       * Return whether the object should be handled via the legacy data framework
       * @param dataObject the data object
       * @return whether the object should be handled via the legacy data framework
       */
     public static boolean useLegacyForObject(Object dataObject) {
         return ld.useLegacyForObject(dataObject);
     }
 
     /**
      * @return whether we are currently in a legacy calling context
      */
     public static boolean isInLegacyContext() {
         return ld.isInLegacyContext();
     }
 
     public static void beginLegacyContext() {
         ld.beginLegacyContext();
     }
 
     public static void endLegacyContext() {
         ld.endLegacyContext();
     }
 
     /**
      * Performs the specified {@link Callable} inside of the legacy context.
      *
      * @param callable the method to call inside of the new contexts
      * @param <T> the return type of the callable
      * @return the result of the callable
      * @throws Exception any exception thrown during the execution of the context
      */
     public static <T> T doInLegacyContext(Callable<T> callable) throws Exception {
         beginLegacyContext();
         try {
             return callable.call();
         } finally {
             endLegacyContext();
         }
     }
 
     /**
      * Performs the specified {@link Callable} inside of both the legacy context (if necessary as dependent on the
      * {@code documentId}) and in new {@link GlobalVariables} as specified by the given {@code userSession}.
      *
      * @param documentId id of the document for which to establish the data context
      * @param userSession the new user session to establish
      * @param callable the method to call inside of the new contexts
      * @param <T> the return type of the callable
      * @return the result of the callable
      * @throws Exception any exception thrown during the execution of the context
      */
     public static <T> T doInLegacyContext(String documentId, UserSession userSession, Callable<T> callable) throws Exception {
         boolean inLegacyContext = establishLegacyDataContextIfNecessary(documentId);
         try {
             return GlobalVariables.doInNewGlobalVariables(userSession, callable);
         } finally {
             clearLegacyDataContextIfExists(inLegacyContext);
         }
     }
 
     /**
      * Establish a legacy data context if it deems that it's necessary to do so for the document being processed.
      * Unfortunately for us here, there is really no easy way to tell if the original document was submitted from a
      * legacy context (i.e. KNS + OJB) or if it was submitted from a non-legacy context.
      *
      * <p>This is really only a problem for us if the data object happens to be mapped and configured in both the legacy
      * and non-legacy data frameworks (which may be the case while a conversion is in-progress). In the case that the
      * document or the maintainable happens to be configured for both legacy and non-legacy data frameworks, the best we
      * can do is use the non-legacy framework by default. We will, however, ensure that the document entry is not one of
      * the KNS subclasses, as that will tell us that they have, in fact, converted the document over from KNS to KRAD.
      * </p>
      *
      * @param documentId id of the document for which to establish the data context
      * @return true if a legacy data context was established, false otherwise
      */
     private static boolean establishLegacyDataContextIfNecessary(String documentId) {
         String documentTypeName = KewApiServiceLocator.getWorkflowDocumentService().getDocumentTypeName(documentId);
         DocumentEntry documentEntry = KRADServiceLocatorWeb.getDocumentDictionaryService().getDocumentEntry(documentTypeName);
 
         if (isKnsDocumentEntry(documentEntry)) {
             beginLegacyContext();
 
             return true;
         }
 
         return false;
     }
 
     /**
      * If the given boolean is true, will end any existing legacy data context.
      *
      * @param inLegacyContext whether or not the legacy data context has been established
      */
     private static void clearLegacyDataContextIfExists(boolean inLegacyContext) {
         if (inLegacyContext) {
             endLegacyContext();
         }
     }
 
 }