/**
    * Copyright 2005-2011 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.group;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.List;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.core.api.exception.RiceIllegalArgumentException;
  import org.kuali.rice.core.api.exception.RiceRuntimeException;
  import org.kuali.rice.kew.actionitem.ActionItem;
  import org.kuali.rice.kew.actionlist.service.ActionListService;
  import org.kuali.rice.kew.actionrequest.ActionRequestValue;
  import org.kuali.rice.kew.actionrequest.service.ActionRequestService;
  import org.kuali.rice.kew.api.WorkflowRuntimeException;
  import org.kuali.rice.kew.api.group.GroupMembershipChangeQueue;
  import org.kuali.rice.kew.service.KEWServiceLocator;
  import org.kuali.rice.kew.api.KewApiConstants;
  import org.kuali.rice.kim.api.group.Group;
  import org.kuali.rice.kim.api.identity.principal.Principal;
  import org.kuali.rice.kim.api.services.KimApiServiceLocator;
  
  /**
   * Executes the updating of {@link ActionItem}s for a {@link Group} when
   * the membership of a group changes.  This keeps users' Action Lists
   * in-sync with their group membership.  Allowing their Action List to
   * be updated for requests routed to groups that they are either added to
   * or removed from.
   *
   * @see ActionItem
   * @see Group 
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class GroupMembershipChangeQueueImpl implements GroupMembershipChangeQueue {
      
      /**
       * @see org.kuali.rice.kew.api.group.GroupMembershipChangeQueue#notifyMembershipChange(java.lang.String, java.lang.String, java.lang.String)
       */
      @Override
      public void notifyMembershipChange(String operation, String groupId, String principalId) {
          if (StringUtils.isBlank(operation)) {
  			throw new RiceIllegalArgumentException("operation was blank or null");
  		}
  
          if (StringUtils.isBlank(groupId)) {
  			throw new RiceIllegalArgumentException("groupId was blank or null");
  		}
  
          if (StringUtils.isBlank(principalId)) {
  			throw new RiceIllegalArgumentException("principalId was blank or null");
  		}
  
          Principal principal = KimApiServiceLocator.getIdentityService().getPrincipal(principalId);
          if (principal == null) {
              throw new RiceRuntimeException("Could not locate the user for the given principal id '" + principalId + "'");
          }
          Group group = KimApiServiceLocator.getGroupService().getGroup(groupId);
          if (group == null) {
              throw new RiceRuntimeException("Could not locate the group with the given id '" + groupId + "'");
          }
          if (KewApiConstants.GroupMembershipChangeOperations.ADDED.equalsIgnoreCase(operation)) {
              updateActionListForUserAddedToGroup(principalId, groupId);
          } else if (KewApiConstants.GroupMembershipChangeOperations.REMOVED.equalsIgnoreCase(operation)) {
              updateActionListForUserRemovedFromGroup(principalId, groupId);
          } else {
              throw new WorkflowRuntimeException("Did not understand requested group membership change operation '" + operation + "'");
          }
      }
  
      
      /**
       * Update the user's Action List to reflect their addition to the given Workgroup.
       */
      private void updateActionListForUserAddedToGroup(String principalId, String groupId) {
          List<ActionRequestValue> actionRequests = new ArrayList<ActionRequestValue>();
          List<String> parentGroupIds = KimApiServiceLocator.getGroupService().getParentGroupIds(groupId);
          List<String> allGroupsToCheck = new ArrayList<String>();
          allGroupsToCheck.add(0, groupId);
          allGroupsToCheck.addAll(parentGroupIds);
          for (String groupToCheckId : allGroupsToCheck) {
              actionRequests.addAll(getActionRequestService().findActivatedByGroup(groupToCheckId));
          }
          for (ActionRequestValue request : actionRequests) {
             ActionItem item = getActionListService().createActionItemForActionRequest(request);
             item.setPrincipalId(principalId);
             getActionListService().saveActionItem(item);
         }
     }
     
     private void updateActionListForUserRemovedFromGroup(String principalId, String groupId) {
         List<String> parentGroupIds = KimApiServiceLocator.getGroupService().getParentGroupIds(groupId);
         List<String> allGroupsToCheck = new ArrayList<String>();
         allGroupsToCheck.add(0, groupId);
         allGroupsToCheck.addAll(parentGroupIds);
         Collection<ActionItem> actionItems = getActionListService().findByPrincipalId(principalId);
         for (Iterator<ActionItem> itemIt = actionItems.iterator(); itemIt.hasNext();) {
             ActionItem item = itemIt.next();
             if (item.isWorkgroupItem()) {
                 for (String groupIdToCheck : allGroupsToCheck) {
                     if (item.getGroupId().equals(groupIdToCheck)) {
                         getActionListService().deleteActionItem(item);
                     }
                 }
             }
         }
     } 
     
     public ActionRequestService getActionRequestService() {
         return KEWServiceLocator.getActionRequestService();
     }
     
     public ActionListService getActionListService() {
         return KEWServiceLocator.getActionListService();
     }
 }