/*

  * Copyright 2007 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 java.util.ArrayList;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 import org.apache.commons.lang.StringUtils;

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

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

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

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

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

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

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

 import org.kuali.rice.kew.rule.FlexRM;

 import org.kuali.rice.kew.rule.KRAMetaRuleEngine;

 import org.kuali.rice.kew.rule.RuleExpressionResult;

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

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

 /**

  * Node that implements a KRAMetaRule, with multiple request/response phases

  *

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

  */

 public class KRAMetaRuleNode extends IteratedRequestActivationNode {

     private static String SUPPRESS_POLICY_ERRORS_KEY = "_suppressPolicyErrorsRequestActivationNode";

     protected List<ActionRequestValue> generateUninitializedRequests(ActionRequestFactory arFactory, RouteContext context, RuleExpressionResult result) throws WorkflowException {

         FlexRM flexRM = new FlexRM();

         flexRM.makeActionRequests(arFactory, result.getResponsibilities(), context, result.getRule().getDefinition(), context.getDocument(), null, null);

         return new ArrayList<ActionRequestValue>(arFactory.getRequestGraphs());

     }

     protected List<ActionRequestValue> initializeRequests(List<ActionRequestValue> requests, RouteContext context) {

         // RequestNode.getNewActionRequests

         List<ActionRequestValue> newRequests = new ArrayList<ActionRequestValue>();

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

             ActionRequestValue actionRequest = (ActionRequestValue) iterator.next();

             actionRequest = KEWServiceLocator.getActionRequestService().initializeActionRequestGraph(actionRequest, context.getDocument(), context.getNodeInstance());

             saveActionRequest(context, actionRequest);

             newRequests.add(actionRequest);

         }

         return newRequests;

     }

     @Override

     protected boolean generateNewRequests(boolean initial, RouteContext context, RouteHelper routeHelper)

             throws WorkflowException, Exception {

         RouteNodeInstance nodeInstance = context.getNodeInstance();

         RouteNode nodeDef = nodeInstance.getRouteNode();

         // get the expression

         Map<String, String> cfg = Utilities.getKeyValueCollectionAsMap(nodeDef.getConfigParams());

         String expression = cfg.get("expression");

         if (StringUtils.isEmpty(expression)) {

             throw new WorkflowException("No meta-rule expression supplied in node " + nodeDef);

         }

         KRAMetaRuleEngine engine = new KRAMetaRuleEngine(expression);

         // get the current statement

         int curStatement = getCurStatement(nodeInstance);

         engine.setCurStatement(curStatement);

         if (engine.isDone()) {

             return false;

         }

         // generate next round of action requests

         RuleExpressionResult result = engine.processSingleStatement(context);

         if (!result.isSuccess()) {

             return false;

         }

         boolean suppressPolicyErrors = isSupressingPolicyErrors(context);

         boolean pastFinalApprover = isPastFinalApprover(context.getDocument(), nodeInstance);

         // actionRequests.addAll(makeActionRequests(context, rule, routeHeader, null, null));

         // copied from parts of FlexRM and RequestsNode

         ActionRequestFactory arFactory = new ActionRequestFactory(context.getDocument(), context.getNodeInstance());

         List<ActionRequestValue> requests = generateUninitializedRequests(arFactory, context, result);

         requests = initializeRequests(requests, context);

         // RequestNode

         if ((requests.isEmpty()) && nodeDef.getMandatoryRouteInd().booleanValue() && ! suppressPolicyErrors) {

             LOG.warn("no requests generated for mandatory route - " + nodeDef.getRouteNodeName());

             throw new RouteManagerException("No requests generated for mandatory route " + nodeDef.getRouteNodeName() + ":" + nodeDef.getRouteMethodName(), context);

         }

         // determine if we have any approve requests for FinalApprover checks

         boolean hasApproveRequest = false;

         for (Iterator iter = requests.iterator(); iter.hasNext();) {

             ActionRequestValue actionRequest = (ActionRequestValue) iter.next();

             hasApproveRequest = actionRequest.isApproveOrCompleteRequest() || hasApproveRequest;

         }

         // if final approver route level and no approve request send to exception routing

         if (nodeDef.getFinalApprovalInd().booleanValue()) {

             // we must have an approve request generated if final approver level.

             if (!hasApproveRequest && ! suppressPolicyErrors) {

                 throw new RuntimeException("No Approve Request generated after final approver");

             }

         } else if (pastFinalApprover) {

             // we can't allow generation of approve requests after final approver. This guys going to exception routing.

             if (hasApproveRequest && ! suppressPolicyErrors) {

                 throw new RuntimeException("Approve Request generated after final approver");

             }

         }

         // increment to next statement

         nodeInstance.getNodeState("stmt").setValue(String.valueOf(curStatement + 1));

         return !requests.isEmpty();

     }

     /**

      * @param nodeInstance the current node instance under execution

      * @return the meta-rule statement this node instance should process

      */

     protected static int getCurStatement(RouteNodeInstance nodeInstance) {

         int statement = 0;

         NodeState nodeState = nodeInstance.getNodeState("stmt");

         if (nodeState == null) {

             nodeState = new NodeState();

             nodeState.setKey("stmt");

             nodeState.setNodeInstance(nodeInstance);

             nodeInstance.addNodeState(nodeState);

         }

         if (StringUtils.isEmpty(nodeState.getValue())) {

             nodeState.setValue("0");

         } else {

             statement = Integer.parseInt(nodeState.getValue());

         }

         return statement;

     }

     @Override

     protected RequestFulfillmentCriteria getRequestFulfillmentCriteria(RouteContext routeContext) {

         return super.getRequestFulfillmentCriteria(routeContext);

     }

     // -- copied from request node; a lot of this action request evaluating code should probably go into helper classes or factored into a common subclass

     /**

      * The method will get a key value which can be used for comparison purposes. If the node instance has a primary key value, it will be returned. However, if the node instance has not been saved to the database (i.e. during a simulation) this method will return the node instance passed in.

      */

     private Object getKey(RouteNodeInstance nodeInstance) {

             Long id = nodeInstance.getRouteNodeInstanceId();

             return (id != null ? (Object) id : (Object) nodeInstance);

     }

     /**

      * Checks if the document has past the final approver node by walking backward through the previous node instances.

      * Ignores any previous nodes that have been "revoked".

      */

     private boolean isPastFinalApprover(DocumentRouteHeaderValue document, RouteNodeInstance nodeInstance) {

             FinalApproverContext context = new FinalApproverContext();

             List revokedNodeInstances = KEWServiceLocator.getRouteNodeService().getRevokedNodeInstances(document);

             Set revokedNodeInstanceIds = new HashSet();

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

                     RouteNodeInstance revokedNodeInstance = (RouteNodeInstance) iterator.next();

                     revokedNodeInstanceIds.add(revokedNodeInstance.getRouteNodeInstanceId());

             }

             isPastFinalApprover(nodeInstance.getPreviousNodeInstances(), context, revokedNodeInstanceIds);

             return context.isPast;

     }

     private void isPastFinalApprover(List previousNodeInstances, FinalApproverContext context, Set revokedNodeInstanceIds) {

         if (previousNodeInstances != null && !previousNodeInstances.isEmpty()) {

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

                         if (context.isPast) {

                                 return;

                         }

                         RouteNodeInstance nodeInstance = (RouteNodeInstance) iterator.next();

                         if (context.inspected.contains(getKey(nodeInstance))) {

                                 continue;

                         } else {

                                 context.inspected.add(getKey(nodeInstance));

                         }

                         if (Boolean.TRUE.equals(nodeInstance.getRouteNode().getFinalApprovalInd())) {

                                 // if the node instance has been revoked (by a Return To Previous action for example)

                                 // then we don't want to consider that node when we determine if we are past final

                                 // approval or not

                                 if (!revokedNodeInstanceIds.contains(nodeInstance.getRouteNodeInstanceId())) {

                                         context.isPast = true;

                                 }

                                 return;

                         }

                         isPastFinalApprover(nodeInstance.getPreviousNodeInstances(), context, revokedNodeInstanceIds);

                 }

         }

 }

     public static boolean isSupressingPolicyErrors(RouteContext routeContext) {

         Boolean suppressPolicyErrors = (Boolean)routeContext.getParameters().get(SUPPRESS_POLICY_ERRORS_KEY);

         if (suppressPolicyErrors == null || ! suppressPolicyErrors) {

                 return false;

         }

         return true;

     }

     private class FinalApproverContext {

         public Set inspected = new HashSet();

         public boolean isPast = false;

 }

 }