/*

  * Copyright 2005-2007 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.routemodule;

 import java.io.ByteArrayInputStream;

 import java.util.ArrayList;

 import java.util.List;

 import javax.xml.xpath.XPath;

 import javax.xml.xpath.XPathConstants;

 import org.apache.commons.lang.StringUtils;

 import org.apache.log4j.Logger;

 import org.jdom.Document;

 import org.jdom.Element;

 import org.kuali.rice.core.reflect.ObjectDefinition;

 import org.kuali.rice.core.resourceloader.GlobalResourceLoader;

 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.node.RouteNodeInstance;

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

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

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

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

 import org.kuali.rice.kew.rule.bo.RuleAttribute;

 import org.kuali.rice.kew.rule.xmlrouting.GenericXMLRuleAttribute;

 import org.kuali.rice.kew.rule.xmlrouting.XPathHelper;

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

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

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

 import org.kuali.rice.kew.xml.RuleXmlParser;

 import org.kuali.rice.kew.xml.XmlConstants;

 /**

  * A RouteModule that generates requests for responsibilities statically defined

  * in the config block of the node.

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

  */

 public class InlineRequestsRouteModule extends FlexRMAdapter {

     private static final Logger LOG = Logger.getLogger(InlineRequestsRouteModule.class);

     /**

      * This overridden method is used to decipher the inline xpath and responsibilities of a route node definition and use

      * them to create action reqeusts

      * 

      * @see org.kuali.rice.kew.routemodule.FlexRMAdapter#findActionRequests(org.kuali.rice.kew.engine.RouteContext)

      */

     @Override

     public List<ActionRequestValue> findActionRequests(RouteContext context) throws Exception {

         // comment this out while implementing the meta-rules stuff

         // re-implement later

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

         RouteNodeInstance currentNode = context.getNodeInstance();

         String contentFragment = currentNode.getRouteNode().getContentFragment();

         // parse with JDOM to reuse RuleXmlParser

         Document doc = XmlHelper.trimSAXXml(new ByteArrayInputStream(contentFragment.getBytes()));

         Element root = doc.getRootElement();

         List<String> ruleAttributeNames = new ArrayList<String>();

         List<String> ruleAttributeClassNames = new ArrayList<String>();

         List<String> xpathExpressions = new ArrayList<String>();

         // get the list of ruleAttributes to use

         Element ruleAttributes = root.getChild("ruleAttributes");

         if (ruleAttributes != null) {

             for (Object o : ruleAttributes.getChildren("name")) {

                 Element e = (Element) o;

                 ruleAttributeNames.add(e.getText());

             }

             for (Object o : ruleAttributes.getChildren("className")) {

                 Element e = (Element) o;

                 ruleAttributeClassNames.add(e.getText());

             }

         }

         // get the list of xpath expressions to verify

         for (Object o: root.getChildren("match")) {

             Element e = (Element) o;

             xpathExpressions.add(e.getText());

         }

         if ( (ruleAttributeNames.isEmpty()) && (ruleAttributeClassNames.isEmpty()) && (xpathExpressions.isEmpty()) ) {

             throw new RuntimeException("Match xpath expression not specified (should be parse-time exception...)");

         }

         List<WorkflowAttribute> attributes = new ArrayList<WorkflowAttribute>();

         for (String attributeName : ruleAttributeNames) {

             attributes.add(getRuleAttributeByName(attributeName));

         }

         for (String attributeClassName : ruleAttributeClassNames) {

             attributes.add(getRuleAttributeByClassName(attributeClassName));

         }

         // at this point if we have no xpath expressions or attributes we cannot match

         if (attributes.isEmpty() && xpathExpressions.isEmpty()) {

             return actionRequests;

         }

         Boolean match = Boolean.TRUE;

         if (!xpathExpressions.isEmpty()) {

             XPath xpath = XPathHelper.newXPath();

             for (String xpathExpression : xpathExpressions) {

                 match &= (Boolean) xpath.evaluate(xpathExpression, context.getDocumentContent().getDocument(), XPathConstants.BOOLEAN);

             }

         }

         for (WorkflowAttribute workflowAttribute : attributes) {

             // no rule extensions to pass in below because we have no rule... simple attribute matching only

             match &= workflowAttribute.isMatch(context.getDocumentContent(), new ArrayList<RuleExtension>());

         }

         if (match.booleanValue()) {

 //            LOG.debug("Expression '" + xpathExpression + "' matched document '" + context.getDocumentContent().getDocContent() + "'");

         } else {

             // return an empty list because we didn't find a match using the given xpath

 //            LOG.debug("Expression '" + xpathExpression + "' did NOT match document '" + context.getDocumentContent().getDocContent() + "'");

             return actionRequests;

         }

         List<RuleResponsibility> responsibilities = new ArrayList<RuleResponsibility>();

         RuleXmlParser parser = new RuleXmlParser();

         ActionRequestFactory arf = new ActionRequestFactory(context.getDocument(), currentNode);

         // this rule is only used to obtain description, forceAction flag, and the rulebasevalues id, which may be null

         RuleBaseValues fakeRule = new RuleBaseValues();

         fakeRule.setActiveInd(Boolean.TRUE);

         fakeRule.setCurrentInd(Boolean.TRUE);

         fakeRule.setDescription("a fake rule");

         fakeRule.setForceAction(Boolean.TRUE);

         fakeRule.setRuleBaseValuesId(null);

         for (Object o: root.getChildren("responsibility", XmlConstants.RULE_NAMESPACE)) {

             Element e = (Element) o;

             RuleResponsibility responsibility = parser.parseResponsibility(e, fakeRule);

             responsibility.setResponsibilityId(KEWConstants.MACHINE_GENERATED_RESPONSIBILITY_ID);

             responsibilities.add(responsibility);

         }

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

             throw new RuntimeException("No responsibilities found on node " + currentNode.getName());

         }

         makeActionRequests(arf, responsibilities, context, fakeRule, context.getDocument(), null, null); 

         actionRequests.addAll(arf.getRequestGraphs());

         return actionRequests;

     }

     @Override

     public String toString() {

         return "InlineRequestsRouteModule";

     }

     private WorkflowAttribute getRuleAttributeByName(String ruleAttributeName) {

         return materializeRuleAttribute(KEWServiceLocator.getRuleAttributeService().findByName(ruleAttributeName));

     }

     private WorkflowAttribute getRuleAttributeByClassName(String ruleAttributeClassName) {

         return materializeRuleAttribute(KEWServiceLocator.getRuleAttributeService().findByClassName(ruleAttributeClassName));

     }

     private WorkflowAttribute materializeRuleAttribute(RuleAttribute ruleAttribute) {

         if (ruleAttribute != null) {

             if (KEWConstants.RULE_ATTRIBUTE_TYPE.equals(ruleAttribute.getType())) {

                 ObjectDefinition objDef = new ObjectDefinition(ruleAttribute.getClassName(), ruleAttribute.getServiceNamespace());

                 return (WorkflowAttribute) GlobalResourceLoader.getObject(objDef);

             } else if (KEWConstants.RULE_XML_ATTRIBUTE_TYPE.equals(ruleAttribute.getType())) {

                 ObjectDefinition objDef = new ObjectDefinition(ruleAttribute.getClassName(), ruleAttribute.getServiceNamespace());

                 WorkflowAttribute workflowAttribute = (WorkflowAttribute) GlobalResourceLoader.getObject(objDef);

                 //required to make it work because ruleAttribute XML is required to construct custom columns

                 ((GenericXMLRuleAttribute) workflowAttribute).setRuleAttribute(ruleAttribute);

                 return workflowAttribute;

             }

         }

         return null;

     }

 }