/*

  * Copyright 2005-2008 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.engine.transition;

 import org.kuali.rice.kew.engine.RouteContext;

 import org.kuali.rice.kew.engine.RouteHelper;

 import org.kuali.rice.kew.engine.node.Node;

 import org.kuali.rice.kew.engine.node.ProcessResult;

 import org.kuali.rice.kew.engine.node.RouteNode;

 import org.kuali.rice.kew.engine.node.RouteNodeInstance;

 import java.util.ArrayList;

 import java.util.List;

 /**

  * Common superclass for all Transition Engines.  A TransitionEngine handles transitioning into and out of

  * a {@link RouteNodeInstance}.  The TransitionEngine is also responsible for determining if a Node has completed.

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public abstract class TransitionEngine {

         private RouteHelper helper;

         public RouteNodeInstance transitionTo(RouteNodeInstance nextNodeInstance, RouteContext context) throws Exception {

                 return nextNodeInstance;

         }

     /**

      * Tell the WorkflowEngine processing the activeNodeInstance if the node is complete and transitionFrom can 

      * be called.

      *

      * @return boolean

      * @param context for routing

      * @throws Exception

      */

     public abstract ProcessResult isComplete(RouteContext context) throws Exception;

     public Transition transitionFrom(RouteContext context, ProcessResult processResult) throws Exception {

         return new Transition(resolveNextNodeInstances(context.getNodeInstance()));

     }

     protected void setRouteHelper(RouteHelper helper) {

             this.helper = helper;

     }

     protected RouteHelper getRouteHelper() {

             return helper;

     }

     protected Node getNode(RouteNode routeNode, Class nodeClass) throws Exception {

                 return helper.getNode(routeNode);

     }

     /**

      * Determines the next nodes instances for the transition.  If the node instance already

      * has next nodes instances (i.e. a dynamic node), then those will be returned.  Otherwise

      * it will resolve the next nodes from the RouteNode prototype.

      * @param nodeInstance for the transition

      * @param nextRouteNodes list of route notes

      * @return list of route note instances

      */

     protected List<RouteNodeInstance> resolveNextNodeInstances(RouteNodeInstance nodeInstance, List<RouteNode> nextRouteNodes) {

         List<RouteNodeInstance> nextNodeInstances = new ArrayList<RouteNodeInstance>();

         for (RouteNode nextRouteNode : nextRouteNodes)

         {

             RouteNode nextNode = (RouteNode) nextRouteNode;

             RouteNodeInstance nextNodeInstance = getRouteHelper().getNodeFactory().createRouteNodeInstance(nodeInstance.getDocumentId(), nextNode);

             nextNodeInstance.setBranch(nodeInstance.getBranch());

             nextNodeInstance.setProcess(nodeInstance.getProcess());

             nextNodeInstances.add(nextNodeInstance);

         }

         return nextNodeInstances;

     }

     protected List<RouteNodeInstance> resolveNextNodeInstances(RouteNodeInstance nodeInstance) {

         return resolveNextNodeInstances(nodeInstance, nodeInstance.getRouteNode().getNextNodes());

     }

 }