/**

  * 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.engine.node;

 import org.kuali.rice.core.framework.persistence.jpa.OrmUtils;

 import org.kuali.rice.kew.api.WorkflowRuntimeException;

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

 import org.kuali.rice.kew.service.KEWServiceLocator;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.Set;

 import java.util.StringTokenizer;

 /**

  * A basic implementation of the JoinEngine which handles join setup and makes determinations

  * as to when a join condition has been satisfied.

  *

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

  */

 public class BasicJoinEngine implements JoinEngine {

     public static final String EXPECTED_JOINERS = "ExpectedJoiners";

     public static final String ACTUAL_JOINERS = "ActualJoiners";

     public void createExpectedJoinState(RouteContext context, RouteNodeInstance joinInstance, RouteNodeInstance previousNodeInstance) {

         RouteNodeInstance splitNode = previousNodeInstance.getBranch().getSplitNode();

         if (splitNode == null) {

             throw new WorkflowRuntimeException("The split node retrieved from node with name '" + previousNodeInstance.getName() + "' and branch with name '" + previousNodeInstance.getBranch().getName() + "' was null");

         }

         for (Iterator iter = splitNode.getNextNodeInstances().iterator(); iter.hasNext();) {

             RouteNodeInstance splitNodeNextNode = (RouteNodeInstance) iter.next();

             splitNodeNextNode.getBranch().setJoinNode(joinInstance);

             // The saveBranch() call below is necessary for parallel routing to work properly with OJB, but it breaks parallel routing with JPA,

             // so only perform it if KEW is not JPA-enabled.

             if (!OrmUtils.isJpaEnabled("rice.kew")) {

                     saveBranch(context, splitNodeNextNode.getBranch());

             }

             addExpectedJoiner(joinInstance, splitNodeNextNode.getBranch());

         }

         joinInstance.setBranch(splitNode.getBranch());

         joinInstance.setProcess(splitNode.getProcess());

     }

     public void addExpectedJoiner(RouteNodeInstance nodeInstance, Branch branch) {

         addJoinState(nodeInstance, branch, EXPECTED_JOINERS);

     }

     public void addActualJoiner(RouteNodeInstance nodeInstance, Branch branch) {

         addJoinState(nodeInstance, branch, ACTUAL_JOINERS);

     }

     private void addJoinState(RouteNodeInstance nodeInstance, Branch branch, String key) {

         NodeState state = nodeInstance.getNodeState(key);

         if (state == null) {

             state = new NodeState();

             state.setKey(key);

             state.setValue("");

             state.setNodeInstance(nodeInstance);

             nodeInstance.addNodeState(state);

         }

         state.setValue(state.getValue()+branch.getBranchId()+",");

     }

     public boolean isJoined(RouteNodeInstance nodeInstance) {

         NodeState expectedState = nodeInstance.getNodeState(EXPECTED_JOINERS);

         if (expectedState == null || org.apache.commons.lang.StringUtils.isEmpty(expectedState.getValue())) {

             return true;

         }

         NodeState actualState = nodeInstance.getNodeState(ACTUAL_JOINERS);

         Set expectedSet = loadIntoSet(expectedState);

         Set actualSet = loadIntoSet(actualState);

         for (Iterator iterator = expectedSet.iterator(); iterator.hasNext();) {

             String value = (String) iterator.next();

             if (actualSet.contains(value)) {

                 iterator.remove();

             }            

         }

         return expectedSet.size() == 0;

     }

     private Set loadIntoSet(NodeState state) {

         Set set = new HashSet();

         StringTokenizer tokenizer = new StringTokenizer(state.getValue(), ",");

         while (tokenizer.hasMoreTokens()) {

             set.add(tokenizer.nextToken());

         }

         return set;

     }

     private void saveBranch(RouteContext context, Branch branch) {

         if (!context.isSimulation()) {

             KEWServiceLocator.getRouteNodeService().save(branch);

         }

     }

 }