/**
    * Copyright 2005-2012 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.kew.impl.actionlist;
  
  import com.google.common.collect.ArrayListMultimap;
  import com.google.common.collect.ListMultimap;
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.core.api.exception.RiceIllegalArgumentException;
  import org.kuali.rice.kew.api.action.ActionItem;
  import org.kuali.rice.kew.api.action.ActionItemCustomization;
  import org.kuali.rice.kew.doctype.bo.DocumentType;
  import org.kuali.rice.kew.doctype.service.DocumentTypeService;
  import org.kuali.rice.kew.framework.KewFrameworkServiceLocator;
  import org.kuali.rice.kew.framework.actionlist.ActionListCustomizationHandlerService;
  import org.kuali.rice.kew.framework.actionlist.ActionListCustomizationMediator;
  import org.kuali.rice.kew.rule.bo.RuleAttribute;
  
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  /**
   * Internal utility class that partitions ActionItems by application id, and calls the appropriate
   * {@link ActionListCustomizationHandlerService} for each parition to retrieve any customizations.
   */
  public class ActionListCustomizationMediatorImpl implements ActionListCustomizationMediator {
  
      private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(ActionListCustomizationMediatorImpl.class);
  
      private DocumentTypeService documentTypeService;
      private ActionListCustomizationHandlerServiceChooser actionListCustomizationHandlerServiceChooser =
              new ActionListCustomizationHandlerServiceChooser();
  
      /**
       * <p>partitions ActionItems by application id, and calls the appropriate
       * {@link ActionListCustomizationHandlerService} for each parition, merging the results.</p>
       *
       * <dl><dt><b>inherited docs:</b></dt><dd>{@inheritDoc}</dd></dl>
       */
      @Override
      public Map<String, ActionItemCustomization> getActionListCustomizations(String principalId,
              List<ActionItem> actionItems) throws RiceIllegalArgumentException {
          if (StringUtils.isBlank(principalId)) {
              throw new RiceIllegalArgumentException("invalid principalId: " + principalId);
          }
          if (actionItems == null) {
              actionItems = Collections.emptyList();
          }
  
          // map from action item ID to ActionItemCustomization
          Map<String, ActionItemCustomization> results = new HashMap<String, ActionItemCustomization>();
  
          // group each action item by application id that needs to be called for action list customizations (note that
          // the application id comes from the extension/rule attribute record, most action lists will have doc types
          // with no custom action list attribute, though the default still needs to be run in this case)
  
          ListMultimap<String, ActionItem> itemsByApplicationId = ArrayListMultimap.create();
  
          for (ActionItem actionItem : actionItems) {
              //DocumentType docType = KewApiServiceLocator.getDocumentTypeService().getDocumentTypeByName(actionItem.getDocName());
              DocumentType docType = getDocumentTypeService().findByName(actionItem.getDocName());
              if (docType == null) {
                  LOG.error(String.format("Action item %s has an invalid document type name of %s",
                          actionItem.getId(), actionItem.getDocName()));
                  // OK to have a null key, this represents the default app id
                  itemsByApplicationId.put(null, actionItem);
              } else {
                  // OK to have a null key, this represents the default app id
                  itemsByApplicationId.put(getActionListCustomizationApplicationId(docType), actionItem);
              }
          }
  
          // For each application id, pass all action items which might need to be customized (because they have a
          // document type, which declares an action list attribute, which has an application id declared) to the
          // appropriate ActionListCustomizationHandlerService endpoint
  
          for (String applicationId : itemsByApplicationId.keySet()) {
              ActionListCustomizationHandlerService actionListCustomizationHandler =
                      getActionListCustomizationHandlerServiceChooser().getByApplicationId(applicationId);
  
              if (actionListCustomizationHandler == null) {
                  // get the local ActionListCustomizationHandlerService as a fallback
                  actionListCustomizationHandler =
                          getActionListCustomizationHandlerServiceChooser().getByApplicationId(null);
              }
 
             List<ActionItemCustomization> customizations =
                     actionListCustomizationHandler.customizeActionList(principalId, itemsByApplicationId.get(
                             applicationId));
 
 
             // Get back the customized results and reassemble with customized results from all different application
             // customizations (as well as default customizations)
             if (customizations != null) for (ActionItemCustomization customization : customizations) {
                 results.put(customization.getActionItemId(), customization);
             }
         }
 
         return results;
     }
 
     // CustomActionListAttributes are configured in RuleAttributes, so that is the
     // applicationId we need to use
     private String getActionListCustomizationApplicationId(DocumentType docType) {
         String applicationId = null;
         RuleAttribute ruleAttribute = docType.getCustomActionListRuleAttribute();
         if (ruleAttribute != null) {
             applicationId = ruleAttribute.getApplicationId();
         }
         // we may return null
         return applicationId;
     }
 
     public DocumentTypeService getDocumentTypeService() {
         return documentTypeService;
     }
 
     public void setDocumentTypeService(DocumentTypeService documentTypeService) {
         this.documentTypeService = documentTypeService;
     }
 
     /**
      * Need this to make our class testable without having to wire the universe up through spring.
      */
     public static class ActionListCustomizationHandlerServiceChooser {
         public ActionListCustomizationHandlerService getByApplicationId(String applicationId) {
             return KewFrameworkServiceLocator.getActionListCustomizationHandlerService(applicationId);
         }
     }
 
     public ActionListCustomizationHandlerServiceChooser getActionListCustomizationHandlerServiceChooser() {
         return actionListCustomizationHandlerServiceChooser;
     }
 
     public void setActionListCustomizationHandlerServiceChooser(
             ActionListCustomizationHandlerServiceChooser actionListCustomizationHandlerServiceChooser) {
         this.actionListCustomizationHandlerServiceChooser = actionListCustomizationHandlerServiceChooser;
     }
 }