/**
    * 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.role;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.commons.lang.exception.ExceptionUtils;
  import org.kuali.rice.core.api.exception.RiceRuntimeException;
  import org.kuali.rice.core.api.reflect.ObjectDefinition;
  import org.kuali.rice.core.api.resourceloader.GlobalResourceLoader;
  import org.kuali.rice.kew.actionrequest.ActionRequestFactory;
  import org.kuali.rice.kew.actionrequest.ActionRequestValue;
  import org.kuali.rice.kew.api.KewApiServiceLocator;
  import org.kuali.rice.kew.api.action.ActionRequestPolicy;
  import org.kuali.rice.kew.api.exception.WorkflowException;
  import org.kuali.rice.kew.api.extension.ExtensionDefinition;
  import org.kuali.rice.kew.api.extension.ExtensionUtils;
  import org.kuali.rice.kew.engine.RouteContext;
  import org.kuali.rice.kew.engine.node.RouteNodeUtils;
  import org.kuali.rice.kew.routemodule.RouteModule;
  import org.kuali.rice.kew.rule.XmlConfiguredAttribute;
  import org.kuali.rice.kew.rule.bo.RuleAttribute;
  import org.kuali.rice.kew.service.KEWServiceLocator;
  import org.kuali.rice.kew.api.KewApiConstants;
  import org.kuali.rice.kew.util.ResponsibleParty;
  import org.kuali.rice.kim.api.KimConstants;
  import org.kuali.rice.kim.api.responsibility.ResponsibilityAction;
  import org.kuali.rice.kim.api.responsibility.ResponsibilityService;
  import org.kuali.rice.kim.api.services.KimApiServiceLocator;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  /**
   * The RoleRouteModule is responsible for interfacing with the KIM
   * Role system to provide Role-based routing to KEW. 
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class RoleRouteModule implements RouteModule {
      private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(RoleRouteModule.class);
  	
  	protected static final String QUALIFIER_RESOLVER_ELEMENT = KewApiConstants.ROLEROUTE_QUALIFIER_RESOLVER_ELEMENT;
  	protected static final String QUALIFIER_RESOLVER_CLASS_ELEMENT = KewApiConstants.ROLEROUTE_QUALIFIER_RESOLVER_CLASS_ELEMENT;
  	protected static final String RESPONSIBILITY_TEMPLATE_NAME_ELEMENT = KewApiConstants.ROLEROUTE_RESPONSIBILITY_TEMPLATE_NAME_ELEMENT;
  	protected static final String NAMESPACE_ELEMENT = KewApiConstants.ROLEROUTE_NAMESPACE_ELEMENT;
  	
  	private static ResponsibilityService responsibilityService;
  	
  	private String qualifierResolverName;
  	private String qualifierResolverClassName;
  	private String responsibilityTemplateName;
  	private String namespace;
  
      @Override
      public boolean isMoreRequestsAvailable(RouteContext context) {
          return false;
      }
  
  	@SuppressWarnings("unchecked")
  	public List<ActionRequestValue> findActionRequests(RouteContext context)
  			throws Exception {
  		
  		ActionRequestFactory arFactory = new ActionRequestFactory(context.getDocument(), context.getNodeInstance());
  
  		QualifierResolver qualifierResolver = loadQualifierResolver(context);
  		List<Map<String, String>> qualifiers = qualifierResolver.resolve(context);
  		String responsibilityTemplateName = loadResponsibilityTemplateName(context);
  		String namespaceCode = loadNamespace(context);
  		Map<String, String> responsibilityDetails = loadResponsibilityDetails(context);
  		if (LOG.isDebugEnabled()) {
  			logQualifierCheck(namespaceCode, responsibilityTemplateName, responsibilityDetails, qualifiers);
  		}
  		if ( qualifiers != null ) {
  			for (Map<String, String> qualifier : qualifiers) {
  				if ( qualifier.containsKey( KimConstants.AttributeConstants.QUALIFIER_RESOLVER_PROVIDED_IDENTIFIER ) ) {
  					responsibilityDetails.put(KimConstants.AttributeConstants.QUALIFIER_RESOLVER_PROVIDED_IDENTIFIER, qualifier.get(KimConstants.AttributeConstants.QUALIFIER_RESOLVER_PROVIDED_IDENTIFIER));
  				} else {
  					responsibilityDetails.remove( KimConstants.AttributeConstants.QUALIFIER_RESOLVER_PROVIDED_IDENTIFIER );
  				}
  				List<ResponsibilityAction> responsibilities = getResponsibilityService().getResponsibilityActionsByTemplate(
                          namespaceCode, responsibilityTemplateName, qualifier, responsibilityDetails);
  				if (LOG.isDebugEnabled()) {
  					LOG.debug("Found " + responsibilities.size() + " responsibilities from ResponsibilityService");
 				}
 				// split the responsibility list defining characteristics (per the ResponsibilitySet.matches() method)
 				List<ResponsibilitySet> responsibilitySets = partitionResponsibilities(responsibilities);
 				if (LOG.isDebugEnabled()) {
 					LOG.debug("Found " + responsibilitySets.size() + " responsibility sets from ResponsibilityActionInfo list");
 				}
 				for (ResponsibilitySet responsibilitySet : responsibilitySets) {
 					String approvePolicy = responsibilitySet.getApprovePolicy();
 					// if all must approve, add the responsibilities individually so that the each get their own approval graph
 					if (ActionRequestPolicy.ALL.getCode().equals(approvePolicy)) {
 						for (ResponsibilityAction responsibility : responsibilitySet.getResponsibilities()) {
 							arFactory.addRoleResponsibilityRequest(Collections.singletonList(responsibility), approvePolicy);
 						}
 					} else {
 						// first-approve policy, pass as groups to the ActionRequestFactory so that a single approval per set will clear the action request
 						arFactory.addRoleResponsibilityRequest(responsibilitySet.getResponsibilities(), approvePolicy);
 					}
 				}
 			}		
 		}
 		List<ActionRequestValue> actionRequests = new ArrayList<ActionRequestValue>(arFactory.getRequestGraphs());
 		disableResolveResponsibility(actionRequests);
 		return actionRequests;
 	}
 	
     protected void logQualifierCheck(String namespaceCode, String responsibilityName, Map<String, String> responsibilityDetails, List<Map<String, String>> qualifiers ) {
 		StringBuilder sb = new StringBuilder();
 		sb.append(  '\n' );
 		sb.append( "Get Resp Actions: " ).append( namespaceCode ).append( "/" ).append( responsibilityName ).append( '\n' );
 		sb.append( "             Details:\n" );
 		if ( responsibilityDetails != null ) {
 			sb.append( responsibilityDetails );
 		} else {
 			sb.append( "                         [null]\n" );
 		}
 		sb.append( "             Qualifiers:\n" );
 		for (Map<String, String> qualification : qualifiers) {
 			if ( qualification != null ) {
 				sb.append( qualification );
 			} else {
 				sb.append( "                         [null]\n" );
 			}
 		}
 		if (LOG.isTraceEnabled()) { 
 			LOG.trace( sb.append(ExceptionUtils.getStackTrace(new Throwable())));
 		} else {
 			LOG.debug(sb.toString());
 		}
     }
 
     /**
 	 * Walks the ActionRequest graph and disables responsibility resolution on those ActionRequests.
 	 * Because of the fact that it's not possible to tell if an ActionRequest was generated by
 	 * KIM once it's been saved in the database, we want to disable responsibilityId
 	 * resolution on the RouteModule because we will end up geting a reference to FlexRM and
 	 * a call to resolveResponsibilityId will fail.
 	 * 
 	 * @param actionRequests
 	 */
 	protected void disableResolveResponsibility(List<ActionRequestValue> actionRequests) {
 		for (ActionRequestValue actionRequest : actionRequests) {
 			actionRequest.setResolveResponsibility(false);
 			disableResolveResponsibility(actionRequest.getChildrenRequests());
 		}
 	}
 
 	protected QualifierResolver loadQualifierResolver(RouteContext context) {
 		if (StringUtils.isBlank(qualifierResolverName)) {
 			this.qualifierResolverName = RouteNodeUtils.getValueOfCustomProperty(context.getNodeInstance().getRouteNode(), QUALIFIER_RESOLVER_ELEMENT);
 		}
 		if (StringUtils.isBlank(qualifierResolverClassName)) {			
 			this.qualifierResolverClassName = RouteNodeUtils.getValueOfCustomProperty(context.getNodeInstance().getRouteNode(), QUALIFIER_RESOLVER_CLASS_ELEMENT);
 		}
 		QualifierResolver resolver = null;
 		if (!StringUtils.isBlank(qualifierResolverName)) {
 			//RuleAttribute ruleAttribute = KEWServiceLocator.getRuleAttributeService().findByName(qualifierResolverName);
             ExtensionDefinition extDef = KewApiServiceLocator.getExtensionRepositoryService().getExtensionByName(qualifierResolverName);
 			if (extDef == null) {
 				throw new RiceRuntimeException("Failed to locate QualifierResolver for name: " + qualifierResolverName);
 			}
             resolver = ExtensionUtils.loadExtension(extDef, extDef.getApplicationId());
 			if (resolver instanceof XmlConfiguredAttribute) {
 				((XmlConfiguredAttribute)resolver).setExtensionDefinition(extDef);
 			}
 		}
 		if (resolver == null && !StringUtils.isBlank(qualifierResolverClassName)) {
 			resolver = (QualifierResolver)GlobalResourceLoader.getObject(new ObjectDefinition(qualifierResolverClassName));
 		}
 		if (resolver == null) {
 			resolver = new NullQualifierResolver();
 		}
 		if (LOG.isDebugEnabled()) {
 			LOG.debug("Resolver class being returned: " + resolver.getClass().getName());
 		}
 		return resolver;
 	}
 	
 	protected Map<String, String> loadResponsibilityDetails(RouteContext context) {
 		String documentTypeName = context.getDocument().getDocumentType().getName();
 		String nodeName = context.getNodeInstance().getName();
 		Map<String, String> responsibilityDetails = new HashMap<String, String>();
 		responsibilityDetails.put(KewApiConstants.DOCUMENT_TYPE_NAME_DETAIL, documentTypeName);
 		responsibilityDetails.put(KewApiConstants.ROUTE_NODE_NAME_DETAIL, nodeName);
 		return responsibilityDetails;
 	}
 	
 	protected String loadResponsibilityTemplateName(RouteContext context) {
 		if (StringUtils.isBlank(responsibilityTemplateName)) {
 			this.responsibilityTemplateName = RouteNodeUtils.getValueOfCustomProperty(context.getNodeInstance().getRouteNode(), RESPONSIBILITY_TEMPLATE_NAME_ELEMENT);
 		}
 		if (StringUtils.isBlank(responsibilityTemplateName)) {
 			this.responsibilityTemplateName = KewApiConstants.DEFAULT_RESPONSIBILITY_TEMPLATE_NAME;
 		}
 		return responsibilityTemplateName;
 	}
 	
 	protected String loadNamespace(RouteContext context) {
 		if (StringUtils.isBlank(namespace)) {
 			this.namespace = RouteNodeUtils.getValueOfCustomProperty(context.getNodeInstance().getRouteNode(), NAMESPACE_ELEMENT);
 		}
 		if (StringUtils.isBlank(namespace)) {
 			this.namespace = KewApiConstants.KEW_NAMESPACE;
 		}
 		return namespace;
 	}
 	
     protected ObjectDefinition getAttributeObjectDefinition(RuleAttribute ruleAttribute) {
     	return new ObjectDefinition(ruleAttribute.getResourceDescriptor(), ruleAttribute.getApplicationId());
     }
     
     protected List<ResponsibilitySet> partitionResponsibilities(List<ResponsibilityAction> responsibilities) {
     	List<ResponsibilitySet> responsibilitySets = new ArrayList<ResponsibilitySet>();
     	for (ResponsibilityAction responsibility : responsibilities) {
     		ResponsibilitySet targetResponsibilitySet = null;
     		for (ResponsibilitySet responsibiliySet : responsibilitySets) {
     			if (responsibiliySet.matches(responsibility)) {
     				targetResponsibilitySet = responsibiliySet;
     			}
     		}
     		if (targetResponsibilitySet == null) {
     			targetResponsibilitySet = new ResponsibilitySet(responsibility);
     			responsibilitySets.add(targetResponsibilitySet);
     		}
     		targetResponsibilitySet.getResponsibilities().add(responsibility);
     	}
     	return responsibilitySets;
     }
 	
 	/**
 	 * Return null so that the responsibility ID will remain the same.
 	 *
 	 * @see org.kuali.rice.kew.routemodule.RouteModule#resolveResponsibilityId(String)
 	 */
 	public ResponsibleParty resolveResponsibilityId(String responsibilityId)
 			throws WorkflowException {
 		return null;
 	}
 	
 	
 	
 	private static class ResponsibilitySet {
 		private String actionRequestCode;
 		private String approvePolicy;
 		private Integer priorityNumber;
 		private String parallelRoutingGroupingCode;
 		private String roleResponsibilityActionId;
 		private List<ResponsibilityAction> responsibilities = new ArrayList<ResponsibilityAction>();
 
 		public ResponsibilitySet(ResponsibilityAction responsibility) {
 			this.actionRequestCode = responsibility.getActionTypeCode();
 			this.approvePolicy = responsibility.getActionPolicyCode();
 			this.priorityNumber = responsibility.getPriorityNumber();
 			this.parallelRoutingGroupingCode = responsibility.getParallelRoutingGroupingCode();
 			this.roleResponsibilityActionId = responsibility.getRoleResponsibilityActionId();
 		}
 		
 		public boolean matches(ResponsibilityAction responsibility) {
 			return responsibility.getActionTypeCode().equals(actionRequestCode) &&
 				responsibility.getActionPolicyCode().equals(approvePolicy) && 
 				responsibility.getPriorityNumber().equals( priorityNumber ) &&
 				responsibility.getParallelRoutingGroupingCode().equals( parallelRoutingGroupingCode ) &&
 				responsibility.getRoleResponsibilityActionId().equals( roleResponsibilityActionId );
 		}
 
 		public String getActionRequestCode() {
 			return this.actionRequestCode;
 		}
 
 		public String getApprovePolicy() {
 			return this.approvePolicy;
 		}
 		
 		public Integer getPriorityNumber() {
 			return priorityNumber;
 		}
 
 		public List<ResponsibilityAction> getResponsibilities() {
 			return this.responsibilities;
 		}
 
 		public String getParallelRoutingGroupingCode() {
 			return this.parallelRoutingGroupingCode;
 		}
 
 		public String getRoleResponsibilityActionId() {
 			return this.roleResponsibilityActionId;
 		}		
 		
 	}
 
 
 
 	/**
 	 * @param qualifierResolverName the qualifierResolverName to set
 	 */
 	public void setQualifierResolverName(String qualifierResolverName) {
 		this.qualifierResolverName = qualifierResolverName;
 	}
 
 	/**
 	 * @param qualifierResolverClassName the qualifierResolverClassName to set
 	 */
 	public void setQualifierResolverClassName(String qualifierResolverClassName) {
 		this.qualifierResolverClassName = qualifierResolverClassName;
 	}
 
 	/**
 	 * @param responsibilityTemplateName the responsibilityTemplateName to set
 	 */
 	public void setResponsibilityTemplateName(String responsibilityTemplateName) {
 		this.responsibilityTemplateName = responsibilityTemplateName;
 	}
 
 	/**
 	 * @param namespace the namespace to set
 	 */
 	public void setNamespace(String namespace) {
 		this.namespace = namespace;
 	}
 
 	protected ResponsibilityService getResponsibilityService() {
 		if ( responsibilityService == null ) {
 			responsibilityService = KimApiServiceLocator.getResponsibilityService();
 		}
 		return responsibilityService;
 	}
 
 }