/*

  * 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;

 import java.util.ArrayList;

 import java.util.List;

 import org.kuali.rice.kew.actionrequest.ActionRequestValue;

 import org.kuali.rice.kew.doctype.bo.DocumentType;

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

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

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

 import org.kuali.rice.kew.routeheader.DocumentRouteHeaderValue;

 import org.kuali.rice.kew.util.KEWConstants;

 /**

  * Provides utility methods for handling backwards compatibility between KEW releases.

  * Currently, it's primary function is to handle backward compatability between the

  * deprecated "route level" concept and the "node" concept which was introduced in

  * KEW 2.1.

  *

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

  */

 public final class CompatUtils {

     private static RouteHelper helper = new RouteHelper();

         private CompatUtils() {

                 throw new UnsupportedOperationException("do not call");

         }

     public static Integer getLevelForNode(DocumentType documentType, String nodeName) {

         if (isRouteLevelCompatible(documentType)) {

             return getLevelForNode(documentType.getPrimaryProcess().getInitialRouteNode(), nodeName, new Integer(0));

         }

         return new Integer(KEWConstants.INVALID_ROUTE_LEVEL);

     }

     private static Integer getLevelForNode(RouteNode node, String nodeName, Integer currentLevel) {

         // TODO potential for infinite recursion here if their document type has loops in it.  Should this be a concern?

         // If their routing version is really "route level" then there should be no cycles.

         if (node.getRouteNodeName().equals(nodeName)) {

             return currentLevel;

         }

         List nextNodes = node.getNextNodes();

         if (nextNodes.isEmpty()) {

             throw new WorkflowRuntimeException("Could not locate node with name '"+nodeName+"'");

         }

         if (nextNodes.size() > 1) {

             throw new WorkflowRuntimeException("Can only determine route level for document types with no splitting");

         }

         RouteNode nextNode = (RouteNode)nextNodes.get(0);

         return getLevelForNode(nextNode, nodeName, new Integer(currentLevel.intValue()+1));

     }

     /**

      * Returns the RouteNode at the given numerical route level for the given document type.

      * This currently throws a WorkflowException if the document has parallel routing structures

      * because the route level as a number becomes arbitrary in that case. 

      */

     public static RouteNode getNodeForLevel(DocumentType documentType, Integer routeLevel) {

         Object[] node = getNodeForLevel(documentType.getPrimaryProcess().getInitialRouteNode(), routeLevel, new Integer(0));

         return (RouteNode)node[0];

     }

     private static Object[] getNodeForLevel(RouteNode node, Integer routeLevel, Integer currentLevel) {

         if (helper.isSubProcessNode(node)) {

             Object[] result = getNodeForLevel(node.getDocumentType().getNamedProcess(node.getRouteNodeName()).getInitialRouteNode(), routeLevel, currentLevel);

             if (result[0] != null) {

                 node = (RouteNode)result[0];

             }

             currentLevel = (Integer)result[1];

         }

         if (currentLevel.equals(routeLevel)) {

             return new Object[] { node, currentLevel };

         }

         List nextNodes = node.getNextNodes();

         if (nextNodes.isEmpty()) {

             return new Object[] { null, currentLevel };

         }

         if (nextNodes.size() > 1) {

             throw new WorkflowRuntimeException("Cannot determine a route level number for documents with splitting.");

         }

         currentLevel = new Integer(currentLevel.intValue()+1);

         return getNodeForLevel((RouteNode)nextNodes.get(0), routeLevel, currentLevel);

     }

     public static boolean isRouteLevelCompatible(DocumentType documentType) {

         return KEWConstants.ROUTING_VERSION_ROUTE_LEVEL.equals(documentType.getRoutingVersion());

     }

     public static boolean isRouteLevelCompatible(DocumentRouteHeaderValue document) {

         return isRouteLevelCompatible(document.getDocumentType());

     }

     public static boolean isNodalDocument(DocumentRouteHeaderValue document) {

         return KEWConstants.DOCUMENT_VERSION_NODAL == document.getDocVersion().intValue();

     }

     public static boolean isNodalRequest(ActionRequestValue request) {

         return KEWConstants.DOCUMENT_VERSION_NODAL == request.getDocVersion().intValue();

     }

     public static boolean isRouteLevelDocument(DocumentRouteHeaderValue document) {

         return KEWConstants.DOCUMENT_VERSION_ROUTE_LEVEL == document.getDocVersion().intValue();

     }

     public static boolean isRouteLevelRequest(ActionRequestValue request) {

         return KEWConstants.DOCUMENT_VERSION_ROUTE_LEVEL == request.getDocVersion().intValue();

     }

     /**

      * Returns a list of RouteNodes in a flat list which is equivalent to the route level concept of

      * Workflow <= version 2.0.  If the document type is not route level compatible, then this method will throw an error.

      */

     public static List getRouteLevelCompatibleNodeList(DocumentType documentType) {

         if (!isRouteLevelCompatible(documentType)) {

             throw new WorkflowRuntimeException("Attempting to invoke a 'route level' operation on a document which is not route level compatible.");

         }

         Process primaryProcess = documentType.getPrimaryProcess();

         RouteNode routeNode = primaryProcess.getInitialRouteNode();

         List nodes = new ArrayList();

         int count = 0;

         int maxCount = 100;

         while (true) {

             nodes.add(routeNode);

             List nextNodes = routeNode.getNextNodes();

             if (nextNodes.size() == 0) {

                 break;

             }

             if (nextNodes.size() > 1) {

                 throw new RuntimeException("Node has more than one next node!  It is not route level compatible!" + routeNode.getRouteNodeName());

             }

             if (count >= maxCount) {

                 throw new RuntimeException("A runaway loop was detected when attempting to create route level compatible node graph.  documentType=" + documentType.getDocumentTypeId()+","+documentType.getName());

             }

             routeNode = (RouteNode) nextNodes.iterator().next();

         }

         return nodes;

     }

     public static int getMaxRouteLevel(DocumentType documentType) {

         return getRouteLevelCompatibleNodeList(documentType).size();

     }

 }