/**
    * Copyright 2005-2012 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.rule;
  
  import org.joda.time.DateTime;
  import org.kuali.rice.core.api.exception.RiceIllegalArgumentException;
  import org.kuali.rice.kew.api.KewApiServiceLocator;
  import org.kuali.rice.kew.api.WorkflowRuntimeException;
  import org.kuali.rice.kew.api.extension.ExtensionDefinition;
  import org.kuali.rice.kew.api.extension.ExtensionUtils;
  import org.kuali.rice.kew.api.rule.RuleTemplate;
  import org.kuali.rice.kew.api.rule.RuleTemplateAttribute;
  import org.kuali.rice.kew.engine.RouteContext;
  import org.kuali.rice.kew.engine.node.RouteNodeInstance;
  import org.kuali.rice.kew.framework.KewFrameworkServiceLocator;
  import org.kuali.rice.kew.framework.rule.attribute.WorkflowRuleAttributeHandlerService;
  import org.kuali.rice.kew.routeheader.DocumentContent;
  import org.kuali.rice.kew.routeheader.DocumentRouteHeaderValue;
  import org.kuali.rice.kew.rule.bo.RuleTemplateAttributeBo;
  import org.kuali.rice.kew.rule.bo.RuleTemplateBo;
  import org.kuali.rice.kew.service.KEWServiceLocator;
  import org.kuali.rice.kew.util.PerformanceLogger;
  
  import java.sql.Timestamp;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  /**
   * Rule selector that selects rules based on configured template name 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  class TemplateRuleSelector implements RuleSelector {
      /**
       * Records the number of selected rules, prior to MassRuleAttribute filtering
       */
      private int numberOfSelectedRules;
  
      /**
       * @return the number of selected rules, prior to MassRuleAttribute filtering
       */
      int getNumberOfSelectedRules() {
  	return numberOfSelectedRules;
      }
  
      public List<Rule> selectRules(RouteContext context, DocumentRouteHeaderValue routeHeader, RouteNodeInstance nodeInstance, String selectionCriterion, Timestamp effectiveDate) {
          // for TemplateRuleSelector, the criterion is taken as a ruletemplate name
          final String ruleTemplateName = selectionCriterion;
  
          Set<MassRuleAttribute> massRules = new HashSet<MassRuleAttribute>();
          RuleTemplate template = KewApiServiceLocator.getRuleService().getRuleTemplateByName(ruleTemplateName);
          if (template == null) {
              throw new WorkflowRuntimeException("Could not locate the rule template with name " + ruleTemplateName + " on document " + routeHeader.getDocumentId());
          }
          for (RuleTemplateAttribute templateAttribute : template.getActiveRuleTemplateAttributes()) {
              String ruleAttributeName = templateAttribute.getRuleAttribute().getName();
              WorkflowRuleAttributeHandlerService wrahs = KewFrameworkServiceLocator.getWorkflowRuleAttributeHandlerService();
              if (!wrahs.isWorkflowRuleAttribute(ruleAttributeName)) {
                  continue;
              }
              ExtensionDefinition extensionDefinition = KewApiServiceLocator.getExtensionRepositoryService().getExtensionByName(ruleAttributeName);
              Object attribute = ExtensionUtils.loadExtension(extensionDefinition);
              if (attribute == null) {
                  throw new RiceIllegalArgumentException("Failed to load WorkflowRuleAttribute for: " + extensionDefinition);
              }
              if (!WorkflowRuleAttribute.class.isAssignableFrom(attribute.getClass())) {
                  throw new RiceIllegalArgumentException("Failed to locate a WorkflowRuleAttribute with the given name: " + ruleAttributeName);
              }
              if (attribute instanceof XmlConfiguredAttribute) {
                  ((XmlConfiguredAttribute)attribute).setExtensionDefinition(extensionDefinition);
              }
  
              WorkflowRuleAttribute ruleAttribute = (WorkflowRuleAttribute)attribute;
              if (ruleAttribute instanceof MassRuleAttribute) {
                  massRules.add((MassRuleAttribute) attribute);
              }
  
          }
  
          List<org.kuali.rice.kew.api.rule.Rule> rules = Collections.emptyList();
          if (effectiveDate == null) {
              rules = KewApiServiceLocator.getRuleService()
                      .getRulesByTemplateNameAndDocumentTypeName(ruleTemplateName,
                              routeHeader.getDocumentType().getName());
         } else {
             rules = KewApiServiceLocator.getRuleService()
                     .getRulesByTemplateNameAndDocumentTypeNameAndEffectiveDate(ruleTemplateName,
                             routeHeader.getDocumentType().getName(), new DateTime(effectiveDate.getTime()));
         }
         numberOfSelectedRules = rules.size();
 
         // TODO really the route context just needs to be able to support nested create and clears
         // (i.e. a Stack model similar to transaction intercepting in Spring) and we wouldn't have to do this
         if (context.getDocument() == null) {
             context.setDocument(routeHeader);
         }
         if (context.getNodeInstance() == null) {
             context.setNodeInstance(nodeInstance);
         }
         DocumentContent documentContent = context.getDocumentContent();
         PerformanceLogger performanceLogger = new PerformanceLogger();
         // have all mass rule attributes filter the list of non applicable rules
         for (MassRuleAttribute massRuleAttribute : massRules) {
             rules = massRuleAttribute.filterNonMatchingRules(context, rules);
         }
         performanceLogger.log("Time to filter massRules for template " + template.getName());
 
         List<Rule> ruleList = new ArrayList<Rule>(rules.size());
         for (org.kuali.rice.kew.api.rule.Rule ruleDefinition: rules) {
             ruleList.add(new RuleImpl(ruleDefinition));
         }
         return ruleList;
     }
 
 }