/*

  * Copyright 2008-2009 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.kns.workflow.service.impl;

 import java.beans.BeanInfo;

 import java.beans.IntrospectionException;

 import java.beans.Introspector;

 import java.beans.PropertyDescriptor;

 import java.math.BigDecimal;

 import java.sql.Timestamp;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Set;

 import java.util.Stack;

 import org.kuali.rice.kew.docsearch.SearchableAttribute;

 import org.kuali.rice.kew.docsearch.SearchableAttributeDateTimeValue;

 import org.kuali.rice.kew.docsearch.SearchableAttributeFloatValue;

 import org.kuali.rice.kew.docsearch.SearchableAttributeLongValue;

 import org.kuali.rice.kew.docsearch.SearchableAttributeStringValue;

 import org.kuali.rice.kew.docsearch.SearchableAttributeValue;

 import org.kuali.rice.kim.bo.types.dto.AttributeSet;

 import org.kuali.rice.kns.bo.BusinessObject;

 import org.kuali.rice.kns.bo.PersistableBusinessObject;

 import org.kuali.rice.kns.datadictionary.DocumentCollectionPath;

 import org.kuali.rice.kns.datadictionary.DocumentValuePathGroup;

 import org.kuali.rice.kns.datadictionary.RoutingAttribute;

 import org.kuali.rice.kns.datadictionary.RoutingTypeDefinition;

 import org.kuali.rice.kns.datadictionary.SearchingTypeDefinition;

 import org.kuali.rice.kns.datadictionary.WorkflowAttributes;

 import org.kuali.rice.kns.document.Document;

 import org.kuali.rice.kns.service.BusinessObjectMetaDataService;

 import org.kuali.rice.kns.service.KNSServiceLocator;

 import org.kuali.rice.kns.service.PersistenceStructureService;

 import org.kuali.rice.kns.util.KualiDecimal;

 import org.kuali.rice.kns.util.ObjectUtils;

 import org.kuali.rice.kns.workflow.attribute.DataDictionarySearchableAttribute;

 import org.kuali.rice.kns.workflow.service.WorkflowAttributePropertyResolutionService;

 /**

  * The default implementation of the WorkflowAttributePropertyResolutionServiceImpl

  */

 public class WorkflowAttributePropertyResolutionServiceImpl implements WorkflowAttributePropertyResolutionService {

     private PersistenceStructureService persistenceStructureService;

     private BusinessObjectMetaDataService businessObjectMetaDataService;

     /**

      * Using the proper RoutingTypeDefinition for the current routing node of the document, aardvarks out the proper routing type qualifiers

      * @see org.kuali.kfs.sys.document.service.WorkflowAttributePropertyResolutionService#resolveRoutingTypeQualifiers(Document, RoutingTypeDefinition)

      */

     public List<AttributeSet> resolveRoutingTypeQualifiers(Document document, RoutingTypeDefinition routingTypeDefinition) {

         List<AttributeSet> qualifiers = new ArrayList<AttributeSet>();

         if (routingTypeDefinition != null) {

             document.populateDocumentForRouting();

             RoutingAttributeTracker routingAttributeTracker = new RoutingAttributeTracker(routingTypeDefinition.getRoutingAttributes());

             for (DocumentValuePathGroup documentValuePathGroup : routingTypeDefinition.getDocumentValuePathGroups()) {

                 qualifiers.addAll(resolveDocumentValuePath(document, documentValuePathGroup, routingAttributeTracker));

                 routingAttributeTracker.reset();

             }

         }

         return qualifiers;

     }

     /**

      * Resolves all of the values in the given DocumentValuePathGroup from the given BusinessObject

      * @param businessObject the business object which is the source of values

      * @param group the DocumentValuePathGroup which tells us which values we want

      * @return a List of AttributeSets

      */

     protected List<AttributeSet> resolveDocumentValuePath(BusinessObject businessObject, DocumentValuePathGroup group, RoutingAttributeTracker routingAttributeTracker) {

         List<AttributeSet> qualifiers;

         AttributeSet qualifier = new AttributeSet();

         if (group.getDocumentValues() == null && group.getDocumentCollectionPath() == null) {

             throw new IllegalStateException("A document value path group must have the documentValues property set, the documentCollectionPath property set, or both.");

         }

         if (group.getDocumentValues() != null) {

             addPathValuesToQualifier(businessObject, group.getDocumentValues(), routingAttributeTracker, qualifier);

         }

         if (group.getDocumentCollectionPath() != null) {

             qualifiers = resolveDocumentCollectionPath(businessObject, group.getDocumentCollectionPath(), routingAttributeTracker);

             qualifiers = cleanCollectionQualifiers(qualifiers);

             for (AttributeSet collectionElementQualifier : qualifiers) {

                 copyQualifications(qualifier, collectionElementQualifier);

             }

         } else {

             qualifiers = new ArrayList<AttributeSet>();

             qualifiers.add(qualifier);

         }

         return qualifiers;

     }

     /**

      * Resolves document values from a collection path on a given business object

      * @param businessObject the business object which has a collection, each element of which is a source of values

      * @param collectionPath the information about what values to pull from each element of the collection

      * @return a List of AttributeSets

      */

     protected List<AttributeSet> resolveDocumentCollectionPath(BusinessObject businessObject, DocumentCollectionPath collectionPath, RoutingAttributeTracker routingAttributeTracker) {

         List<AttributeSet> qualifiers = new ArrayList<AttributeSet>();

         final Collection collectionByPath = getCollectionByPath(businessObject, collectionPath.getCollectionPath());

         if (!ObjectUtils.isNull(collectionByPath)) {

             if (collectionPath.getNestedCollection() != null) {

                 // we need to go through the collection...

                 for (Object collectionElement : collectionByPath) {

                     // for each element, we need to get the child qualifiers

                     if (collectionElement instanceof BusinessObject) {

                         List<AttributeSet> childQualifiers = resolveDocumentCollectionPath((BusinessObject)collectionElement, collectionPath.getNestedCollection(), routingAttributeTracker);

                         for (AttributeSet childQualifier : childQualifiers) {

                             AttributeSet qualifier = new AttributeSet();

                             routingAttributeTracker.checkPoint();

                             // now we need to get the values for the current element of the collection

                             addPathValuesToQualifier(collectionElement, collectionPath.getDocumentValues(), routingAttributeTracker, qualifier);

                             // and move all the child keys to the qualifier

                             copyQualifications(childQualifier, qualifier);

                             qualifiers.add(qualifier);

                             routingAttributeTracker.backUpToCheckPoint();

                         }

                     }

                 }

             } else {

                 // go through each element in the collection

                 for (Object collectionElement : collectionByPath) {

                     AttributeSet qualifier = new AttributeSet();

                     routingAttributeTracker.checkPoint();

                     addPathValuesToQualifier(collectionElement, collectionPath.getDocumentValues(), routingAttributeTracker, qualifier);

                     qualifiers.add(qualifier);

                     routingAttributeTracker.backUpToCheckPoint();

                 }

             }

         }

         return qualifiers;

     }

     /**

      * Returns a collection from a path on a business object

      * @param businessObject the business object to get values from

      * @param collectionPath the path to that collection

      * @return hopefully, a collection of objects

      */

     protected Collection getCollectionByPath(BusinessObject businessObject, String collectionPath) {

         return (Collection)getPropertyByPath(businessObject, collectionPath.trim());

     }

     /**

      * Aardvarks values out of a business object and puts them into an AttributeSet, based on a List of paths

      * @param businessObject the business object to get values from

      * @param paths the paths of values to get from the qualifier

      * @param routingAttribute the RoutingAttribute associated with this qualifier's document value

      * @param currentRoutingAttributeIndex - the current index of the routing attribute

      * @param qualifier the qualifier to put values into

      */

     protected void addPathValuesToQualifier(Object businessObject, List<String> paths, RoutingAttributeTracker routingAttributes, AttributeSet qualifier) {

         if (ObjectUtils.isNotNull(paths)) {

             for (String path : paths) {

                 // get the values for the paths of each element of the collection

                 final Object value = getPropertyByPath(businessObject, path.trim());

                 if (value != null) {

                     qualifier.put(routingAttributes.getCurrentRoutingAttribute().getQualificationAttributeName(), value.toString());

                 }

                 routingAttributes.moveToNext();

             }

         }

     }

     /**

      * Copies all the values from one qualifier to another

      * @param source the source of values

      * @param target the place to write all the values to

      */

     protected void copyQualifications(AttributeSet source, AttributeSet target) {

         for (String key : source.keySet()) {

             target.put(key, source.get(key));

         }

     }

     /**

      * Resolves all of the searching values to index for the given document, returning a list of SearchableAttributeValue implementations

      * @see org.kuali.kfs.sys.document.service.WorkflowAttributePropertyResolutionService#resolveSearchableAttributeValues(org.kuali.rice.kns.document.Document, org.kuali.rice.kns.datadictionary.WorkflowAttributes)

      */

     public List<SearchableAttributeValue> resolveSearchableAttributeValues(Document document, WorkflowAttributes workflowAttributes) {

         List<SearchableAttributeValue> valuesToIndex = new ArrayList<SearchableAttributeValue>();

         if (workflowAttributes != null && workflowAttributes.getSearchingTypeDefinitions() != null) {

             for (SearchingTypeDefinition definition : workflowAttributes.getSearchingTypeDefinitions()) {

                 valuesToIndex.addAll(aardvarkValuesForSearchingTypeDefinition(document, definition));

             }

         }

         return valuesToIndex;

     }

     /**

      * Pulls SearchableAttributeValue values from the given document for the given searchingTypeDefinition

      * @param document the document to get search values from

      * @param searchingTypeDefinition the current SearchingTypeDefinition to find values for

      * @return a List of SearchableAttributeValue implementations

      */

     protected List<SearchableAttributeValue> aardvarkValuesForSearchingTypeDefinition(Document document, SearchingTypeDefinition searchingTypeDefinition) {

         List<SearchableAttributeValue> searchAttributes = new ArrayList<SearchableAttributeValue>();

         final List<Object> searchValues = aardvarkSearchValuesForPaths(document, searchingTypeDefinition.getDocumentValues());

         for (Object value : searchValues) {

             try {

                 final SearchableAttributeValue searchableAttributeValue = buildSearchableAttribute(((Class<? extends BusinessObject>)Class.forName(searchingTypeDefinition.getSearchingAttribute().getBusinessObjectClassName())), searchingTypeDefinition.getSearchingAttribute().getAttributeName(), value);

                 if (searchableAttributeValue != null) {

                     searchAttributes.add(searchableAttributeValue);

                 }

             }

             catch (ClassNotFoundException cnfe) {

                 throw new RuntimeException("Could not find instance of class "+searchingTypeDefinition.getSearchingAttribute().getBusinessObjectClassName(), cnfe);

             }

         }

         return searchAttributes;

     }

     /**

      * Pulls values as objects from the document for the given paths

      * @param document the document to pull values from

      * @param paths the property paths to pull values

      * @return a List of values as Objects

      */

     protected List<Object> aardvarkSearchValuesForPaths(Document document, List<String> paths) {

         List<Object> searchValues = new ArrayList<Object>();

         for (String path : paths) {

             flatAdd(searchValues, getPropertyByPath(document, path.trim()));

         }

         return searchValues;

     }

     /**

      * Removes empty AttributeSets from the given List of qualifiers

      * @param qualifiers a List of AttributeSets holding qualifiers for responsibilities

      * @return a cleaned up list of qualifiers

      */

     protected List<AttributeSet> cleanCollectionQualifiers(List<AttributeSet> qualifiers) {

        List<AttributeSet> cleanedQualifiers = new ArrayList<AttributeSet>();

        for (AttributeSet qualifier : qualifiers) {

            if (qualifier.size() > 0) {

                cleanedQualifiers.add(qualifier);

            }

        }

        return cleanedQualifiers;

     }

     /**

      * @see org.kuali.kfs.sys.document.service.WorkflowAttributePropertyResolutionService#determineFieldDataType(java.lang.Class, java.lang.String)

      */

     public String determineFieldDataType(Class<? extends BusinessObject> businessObjectClass, String attributeName) {

         final Class attributeClass = thieveAttributeClassFromBusinessObjectClass(businessObjectClass, attributeName);

         if (isStringy(attributeClass)) return SearchableAttribute.DATA_TYPE_STRING; // our most common case should go first

         if (isDecimaltastic(attributeClass)) return SearchableAttribute.DATA_TYPE_FLOAT;

         if (isDateLike(attributeClass)) return SearchableAttribute.DATA_TYPE_DATE;

         if (isIntsy(attributeClass)) return SearchableAttribute.DATA_TYPE_LONG;

         if (isBooleanable(attributeClass)) return DataDictionarySearchableAttribute.DATA_TYPE_BOOLEAN;

         return SearchableAttribute.DATA_TYPE_STRING; // default to String

     }

     /**

      * Using the type of the sent in value, determines what kind of SearchableAttributeValue implementation should be passed back 

      * @param attributeKey

      * @param value

      * @return

      */

     public SearchableAttributeValue buildSearchableAttribute(Class<? extends BusinessObject> businessObjectClass, String attributeKey, Object value) {

         if (value == null) return null;

         final String fieldDataType = determineFieldDataType(businessObjectClass, attributeKey);

         if (fieldDataType.equals(SearchableAttribute.DATA_TYPE_STRING)) return buildSearchableStringAttribute(attributeKey, value); // our most common case should go first

         if (fieldDataType.equals(SearchableAttribute.DATA_TYPE_FLOAT) && isDecimaltastic(value.getClass())) return buildSearchableRealAttribute(attributeKey, value);

         if (fieldDataType.equals(SearchableAttribute.DATA_TYPE_DATE) && isDateLike(value.getClass())) return buildSearchableDateTimeAttribute(attributeKey, value);

         if (fieldDataType.equals(SearchableAttribute.DATA_TYPE_LONG) && isIntsy(value.getClass())) return buildSearchableFixnumAttribute(attributeKey, value);

         if (fieldDataType.equals(DataDictionarySearchableAttribute.DATA_TYPE_BOOLEAN) && isBooleanable(value.getClass())) return buildSearchableYesNoAttribute(attributeKey, value);

         return buildSearchableStringAttribute(attributeKey, value);

     }

     /**

      * Determines if the given Class is a String

      * @param clazz the class to check for Stringiness

      * @return true if the Class is a String, false otherwise

      */

     protected boolean isStringy(Class clazz) {

         return java.lang.String.class.isAssignableFrom(clazz);

     }

     /**

      * Determines if the given class is enough like a date to store values of it as a SearchableAttributeDateTimeValue

      * @param class the class to determine the type of

      * @return true if it is like a date, false otherwise

      */

     protected boolean isDateLike(Class clazz) {

         return java.util.Date.class.isAssignableFrom(clazz);

     }

     /**

      * Determines if the given class is enough like a Float to store values of it as a SearchableAttributeFloatValue

      * @param value the class to determine of the type of

      * @return true if it is like a "float", false otherwise

      */

     protected boolean isDecimaltastic(Class clazz) {

         return java.lang.Double.class.isAssignableFrom(clazz) || java.lang.Float.class.isAssignableFrom(clazz) || clazz.equals(Double.TYPE) || clazz.equals(Float.TYPE) || java.math.BigDecimal.class.isAssignableFrom(clazz) || org.kuali.rice.kns.util.KualiDecimal.class.isAssignableFrom(clazz);

     }

     /**

      * Determines if the given class is enough like a "long" to store values of it as a SearchableAttributeLongValue

      * @param value the class to determine the type of

      * @return true if it is like a "long", false otherwise

      */

     protected boolean isIntsy(Class clazz) {

         return java.lang.Integer.class.isAssignableFrom(clazz) || java.lang.Long.class.isAssignableFrom(clazz) || java.lang.Short.class.isAssignableFrom(clazz) || java.lang.Byte.class.isAssignableFrom(clazz) || java.math.BigInteger.class.isAssignableFrom(clazz) || clazz.equals(Integer.TYPE) || clazz.equals(Long.TYPE) || clazz.equals(Short.TYPE) || clazz.equals(Byte.TYPE);

     }

     /**

      * Determines if the given class is enough like a boolean, to index it as a String "Y" or "N"

      * @param value the class to determine the type of

      * @return true if it is like a boolean, false otherwise

      */

     protected boolean isBooleanable(Class clazz) {

         return java.lang.Boolean.class.isAssignableFrom(clazz) || clazz.equals(Boolean.TYPE);

     }

     /**

      * Given a BusinessObject class and an attribute name, determines the class of that attribute on the BusinessObject class

      * @param boClass a class extending BusinessObject

      * @param attributeKey the name of a field on that class

      * @return the Class of the given attribute

      */

     private Class thieveAttributeClassFromBusinessObjectClass(Class<? extends BusinessObject> boClass, String attributeKey) {

         Class attributeFieldClass = null;

         try {

             final BeanInfo beanInfo = Introspector.getBeanInfo(boClass);

             int i = 0;

             while (attributeFieldClass == null && i < beanInfo.getPropertyDescriptors().length) {

                 final PropertyDescriptor prop = beanInfo.getPropertyDescriptors()[i];

                 if (prop.getName().equals(attributeKey)) {

                     attributeFieldClass = prop.getPropertyType();

                 }

                 i += 1;

             }

         }

         catch (SecurityException se) {

             throw new RuntimeException("Could not determine type of attribute "+attributeKey+" of BusinessObject class "+boClass.getName(), se);

         }

         catch (IntrospectionException ie) {

             throw new RuntimeException("Could not determine type of attribute "+attributeKey+" of BusinessObject class "+boClass.getName(), ie);

         }

         return attributeFieldClass;

     }

     /**

      * Builds a date time SearchableAttributeValue for the given key and value

      * @param attributeKey the key for the searchable attribute

      * @param value the value that will be coerced to date/time data

      * @return the generated SearchableAttributeDateTimeValue

      */

     protected SearchableAttributeDateTimeValue buildSearchableDateTimeAttribute(String attributeKey, Object value) {

         SearchableAttributeDateTimeValue attribute = new SearchableAttributeDateTimeValue();

         attribute.setSearchableAttributeKey(attributeKey);

         attribute.setSearchableAttributeValue(new Timestamp(((java.util.Date)value).getTime()));

         return attribute;

     }

     /**

      * Builds a "float" SearchableAttributeValue for the given key and value

      * @param attributeKey the key for the searchable attribute

      * @param value the value that will be coerced to "float" data

      * @return the generated SearchableAttributeFloatValue

      */

     protected SearchableAttributeFloatValue buildSearchableRealAttribute(String attributeKey, Object value) {

         SearchableAttributeFloatValue attribute = new SearchableAttributeFloatValue();

         attribute.setSearchableAttributeKey(attributeKey);

         if (value instanceof BigDecimal) {

             attribute.setSearchableAttributeValue((BigDecimal)value);

         } else if (value instanceof KualiDecimal) {

             attribute.setSearchableAttributeValue(((KualiDecimal)value).bigDecimalValue());

         } else {

             attribute.setSearchableAttributeValue(new BigDecimal(((Number)value).doubleValue()));

         }

         return attribute;

     }

     /**

      * Builds a "integer" SearchableAttributeValue for the given key and value

      * @param attributeKey the key for the searchable attribute

      * @param value the value that will be coerced to "integer" type data

      * @return the generated SearchableAttributeLongValue

      */

     protected SearchableAttributeLongValue buildSearchableFixnumAttribute(String attributeKey, Object value) {

         SearchableAttributeLongValue attribute = new SearchableAttributeLongValue();

         attribute.setSearchableAttributeKey(attributeKey);

         attribute.setSearchableAttributeValue(new Long(((Number)value).longValue()));

         return attribute;

     }

     /**

      * Our last ditch attempt, this builds a String SearchableAttributeValue for the given key and value

      * @param attributeKey the key for the searchable attribute

      * @param value the value that will be coerced to a String

      * @return the generated SearchableAttributeStringValue

      */

     protected SearchableAttributeStringValue buildSearchableStringAttribute(String attributeKey, Object value) {

         SearchableAttributeStringValue attribute = new SearchableAttributeStringValue();

         attribute.setSearchableAttributeKey(attributeKey);

         attribute.setSearchableAttributeValue(value.toString());

         return attribute;

     }

     /**

      * This builds a String SearchableAttributeValue for the given key and value, correctly correlating booleans

      * @param attributeKey the key for the searchable attribute

      * @param value the value that will be coerced to a String

      * @return the generated SearchableAttributeStringValue

      */

     protected SearchableAttributeStringValue buildSearchableYesNoAttribute(String attributeKey, Object value) {

         SearchableAttributeStringValue attribute = new SearchableAttributeStringValue();

         attribute.setSearchableAttributeKey(attributeKey);

         final String boolValueAsString = booleanValueAsString((Boolean)value);

         attribute.setSearchableAttributeValue(boolValueAsString);

         return attribute;

     }

     /**

      * Converts the given boolean value to "" for null, "Y" for true, "N" for false

      * @param booleanValue the boolean value to convert

      * @return the corresponding String "Y","N", or ""

      */

     private String booleanValueAsString(Boolean booleanValue) {

         if (booleanValue == null) return "";

         if (booleanValue.booleanValue()) return "Y";

         return "N";

     }

     /**

      * @see org.kuali.kfs.sys.document.service.WorkflowAttributePropertyResolutionService#getPropertyByPath(java.lang.Object, java.lang.String)

      */

     public Object getPropertyByPath(Object object, String path) {

         if (object instanceof Collection) return getPropertyOfCollectionByPath((Collection)object, path);

         final String[] splitPath = headAndTailPath(path);

         final String head = splitPath[0];

         final String tail = splitPath[1];

         if (object instanceof PersistableBusinessObject && tail != null) {

             if (getBusinessObjectMetaDataService().getBusinessObjectRelationship((BusinessObject) object, head) != null) {

                 ((PersistableBusinessObject)object).refreshReferenceObject(head);

             }

         }

         final Object headValue = ObjectUtils.getPropertyValue(object, head);

         if (!ObjectUtils.isNull(headValue)) {

             if (tail == null) {

                 return headValue;

             } else {

                 // we've still got path left...

                 if (headValue instanceof Collection) {

                     // oh dear, a collection; we've got to loop through this

                     Collection values = makeNewCollectionOfSameType((Collection)headValue);

                     for (Object currentElement : (Collection)headValue) {

                         flatAdd(values, getPropertyByPath(currentElement, tail));

                     }

                     return values;

                 } else {

                     return getPropertyByPath(headValue, tail);

                 }

             }

         }

         return null;

     }

     /**

      * Finds a child object, specified by the given path, on each object of the given collection

      * @param collection the collection of objects

      * @param path the path of the property to retrieve

      * @return a Collection of the values culled from each child

      */

     public Collection getPropertyOfCollectionByPath(Collection collection, String path) {

         Collection values = makeNewCollectionOfSameType(collection);

         for (Object o : collection) {

             flatAdd(values, getPropertyByPath(o, path));

         }

         return values;

     }

     /**

      * Makes a new collection of exactly the same type of the collection that was handed to it

      * @param collection the collection to make a new collection of the same type as

      * @return a new collection.  Of the same type.

      */

     public Collection makeNewCollectionOfSameType(Collection collection) {

         if (collection instanceof List) return new ArrayList();

         if (collection instanceof Set) return new HashSet();

         try {

             return collection.getClass().newInstance();

         }

         catch (InstantiationException ie) {

             throw new RuntimeException("Couldn't instantiate class of collection we'd already instantiated??", ie);

         }

         catch (IllegalAccessException iae) {

             throw new RuntimeException("Illegal Access on class of collection we'd already accessed??", iae);

         }

     }

     /**

      * Splits the first property off from a path, leaving the tail

      * @param path the path to split

      * @return an array; if the path is nested, the first element will be the first part of the path up to a "." and second element is the rest of the path while if the path is simple, returns the path as the first element and a null as the second element

      */

     protected String[] headAndTailPath(String path) {

         final int firstDot = path.indexOf('.');

         if (firstDot < 0) {

             return new String[] { path, null };

         }

         return new String[] { path.substring(0, firstDot), path.substring(firstDot + 1) };

     }

     /**

      * Convenience method which makes sure that if the given object is a collection, it is added to the given collection flatly

      * @param c a collection, ready to be added to

      * @param o an object of dubious type

      */

     protected void flatAdd(Collection c, Object o) {

         if (o instanceof Collection) {

             c.addAll((Collection) o);

         } else {

             c.add(o);

         }

     }

     /**

      * Gets the persistenceStructureService attribute. 

      * @return Returns the persistenceStructureService.

      */

     public PersistenceStructureService getPersistenceStructureService() {

         return persistenceStructureService;

     }

     /**

      * Sets the persistenceStructureService attribute value.

      * @param persistenceStructureService The persistenceStructureService to set.

      */

     public void setPersistenceStructureService(PersistenceStructureService persistenceStructureService) {

         this.persistenceStructureService = persistenceStructureService;

     }

     /**

      * Inner helper class which will track which routing attributes have been used

      */

     class RoutingAttributeTracker {

         private List<RoutingAttribute> routingAttributes;

         private int currentRoutingAttributeIndex;

         private Stack<Integer> checkPoints;

         /**

          * Constructs a WorkflowAttributePropertyResolutionServiceImpl

          * @param routingAttributes the routing attributes to track

          */

         public RoutingAttributeTracker(List<RoutingAttribute> routingAttributes) {

             this.routingAttributes = routingAttributes;

             checkPoints = new Stack<Integer>();

         }

         /**

          * @return the routing attribute hopefully associated with the current qualifier

          */

         public RoutingAttribute getCurrentRoutingAttribute() {

             return routingAttributes.get(currentRoutingAttributeIndex);

         }

         /**

          * Moves this routing attribute tracker to its next routing attribute

          */

         public void moveToNext() {

             currentRoutingAttributeIndex += 1;

         }

         /**

          * Check points at the current routing attribute, so that this position is saved

          */

         public void checkPoint() {

             checkPoints.push(new Integer(currentRoutingAttributeIndex));

         }

         /**

          * Returns to the point of the last check point

          */

         public void backUpToCheckPoint() {

             currentRoutingAttributeIndex = checkPoints.pop().intValue();

         }

         /**

          * Resets this RoutingAttributeTracker, setting the current RoutingAttribute back to the top one and

          * clearing the check point stack

          */

         public void reset() {

             currentRoutingAttributeIndex = 0;

             checkPoints.clear();

         }

     }

     protected BusinessObjectMetaDataService getBusinessObjectMetaDataService() {

         if ( businessObjectMetaDataService == null ) {

             businessObjectMetaDataService = KNSServiceLocator.getBusinessObjectMetaDataService();

         }

         return businessObjectMetaDataService;

     }

 }