/*

  * Copyright 2007-2010 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.lookup;

 import java.lang.reflect.InvocationTargetException;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.HashMap;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 import org.apache.commons.beanutils.PropertyUtils;

 import org.apache.commons.lang.StringUtils;

 import org.kuali.rice.core.web.format.Formatter;

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

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

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

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

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

 /**

  * LookupResults support strategy which uses the primary keys and lookupable defined in a business object's data dictionary file to support the multivalue lookup 

  * 

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

  *

  */

 public class DataDictionaryLookupResultsSupportStrategy implements

                 LookupResultsSupportStrategyService {

         private DataDictionaryService dataDictionaryService;

         /**

          * Builds a lookup id for the given business object

          * @see org.kuali.rice.kns.lookup.LookupResultsSupportStrategyService#getLookupIdForBusinessObject(org.kuali.rice.kns.bo.BusinessObject)

          */

         public String getLookupIdForBusinessObject(BusinessObject businessObject) {

                 final List<String> pkFieldNames = getPrimaryKeyFieldsForBusinessObject(businessObject.getClass());

                 return convertPKFieldMapToLookupId(pkFieldNames, businessObject);

         }

         /**

          * Determines if both the primary keys and Lookupable are present in the data dictionary definition; if so, the BO qualifies, but if either are missing, it does not

          * @see org.kuali.rice.kns.lookup.LookupResultsSupportStrategyService#qualifiesForStrategy(java.lang.Class)

          */

         public boolean qualifiesForStrategy(Class<? extends BusinessObject> boClass) {

                 if (getLookupableForBusinessObject(boClass) == null) {

                         return false; // this probably isn't going to happen, but still...

                 }

                 final List<String> pkFields = getPrimaryKeyFieldsForBusinessObject(boClass);

                 return pkFields != null && pkFields.size() > 0;

         }

         /**

          * Uses the Lookupable associated with the given BusinessObject to search for business objects

          * @see org.kuali.rice.kns.lookup.LookupResultsSupportStrategyService#retrieveSelectedResultBOs(java.lang.String, java.lang.Class, java.lang.String, org.kuali.rice.kns.lookup.LookupResultsService)

          */

         public <T extends BusinessObject> Collection<T> retrieveSelectedResultBOs(Class<T> boClass, Set<String> lookupIds) throws Exception {

         List<T> retrievedBusinessObjects = new ArrayList<T>();

         final Lookupable lookupable = getLookupableForBusinessObject(boClass);

         for (String lookupId : lookupIds) {

                 final Map<String, String> lookupKeys = convertLookupIdToPKFieldMap(lookupId, boClass);

                 List<BusinessObject> bos = lookupable.getSearchResults(lookupKeys);

                 // we should only get one business object...but let's put them all in...

                 for (BusinessObject bo : bos) {

                         retrievedBusinessObjects.add((T)bo);

                 }

         }

                 return retrievedBusinessObjects;

         }

         /**

          * Retrieves the Lookupable for the given business object class

          * 

          * @param businessObjectClass the class to find the Lookupable for

          * @return the Lookupable, or null if nothing could be found

          */

         protected Lookupable getLookupableForBusinessObject(Class<? extends BusinessObject> businessObjectClass) {

                 final BusinessObjectEntry boEntry = getBusinessObjectEntry(businessObjectClass);

                 if (boEntry == null) {

                         return null;

                 }

                 final String lookupableId = boEntry.getLookupDefinition().getLookupableID();

                 return KNSServiceLocatorWeb.getLookupable(lookupableId);

         }

         /**

          * Returns the data dictionary defined primary keys for the given BusinessObject

          * 

          * @param businessObjectClass the business object to get DataDictionary defined primary keys for

          * @return the List of primary key property names, or null if nothing could be found

          */

         protected List<String> getPrimaryKeyFieldsForBusinessObject(Class<? extends BusinessObject> businessObjectClass) {

                 final BusinessObjectEntry boEntry = getBusinessObjectEntry(businessObjectClass);

                 if (boEntry == null) {

                         return null;

                 }

                 return boEntry.getPrimaryKeys();

         }

         /**

          * Converts a lookup id into a PK field map to use to search in a lookupable

          * 

          * @param lookupId the id returned by the lookup

          * @param businessObjectClass the class of the business object getting the primary key

          * @return a Map of field names and values which can be profitably used to search for matching business objects

          */

         protected Map<String, String> convertLookupIdToPKFieldMap(String lookupId, Class<? extends BusinessObject> businessObjectClass) {

                 Map<String, String> pkFields = new HashMap<String, String>();

                 if (!StringUtils.isBlank(lookupId)) {

                         final String[] pkValues = lookupId.split("\\|");

                         for (String pkValue : pkValues) {

                                 if (!StringUtils.isBlank(pkValue)) {

                                         final String[] pkPieces = pkValue.split("-");

                                         if (!StringUtils.isBlank(pkPieces[0]) && !StringUtils.isBlank(pkPieces[1])) {

                                                 pkFields.put(pkPieces[0], pkPieces[1]);

                                         }

                                 }

                         }

                 }

                 return pkFields;

         }

         /**

          * Converts a Map of PKFields into a String lookup ID

          * @param pkFieldNames the name of the PK fields, which should be converted to the given lookupId

          * @param businessObjectClass the class of the business object getting the primary key

          * @return the String lookup id

          */

         protected String convertPKFieldMapToLookupId(List<String> pkFieldNames, BusinessObject businessObject) {

                 StringBuilder lookupId = new StringBuilder();

                 for (String pkFieldName : pkFieldNames) {

                         try {

                                 final Object value = PropertyUtils.getProperty(businessObject, pkFieldName);

                                 if (value != null) {

                                         lookupId.append(pkFieldName);

                                         lookupId.append("-");

                                         final Formatter formatter = retrieveBestFormatter(pkFieldName, businessObject.getClass());

                                         final String formattedValue = (formatter != null) ? formatter.format(value).toString() : value.toString();

                                         lookupId.append(formattedValue);

                                 }

                                 lookupId.append("|");

                         } catch (IllegalAccessException iae) {

                                 throw new RuntimeException("Could not retrieve pk field value "+pkFieldName+" from business object "+businessObject.getClass().getName(), iae);

                         } catch (InvocationTargetException ite) {

                                 throw new RuntimeException("Could not retrieve pk field value "+pkFieldName+" from business object "+businessObject.getClass().getName(), ite);

                         } catch (NoSuchMethodException nsme) {

                                 throw new RuntimeException("Could not retrieve pk field value "+pkFieldName+" from business object "+businessObject.getClass().getName(), nsme);

                         }

                 }

                 return lookupId.substring(0, lookupId.length() - 1); // kill the last "|"

         }

         /**

          * Like when you're digging through your stuff drawer, you know the one in the kitchen with all the batteries and lint in it, this method

          * goes through the stuff drawer of KNS formatters and attempts to return you a good one

          * 

          * @param propertyName the name of the property to retrieve

          * @param boClass the class of the BusinessObject the property is on

          * @return a Formatter, or null if we were unsuccessful in finding

          */

         protected Formatter retrieveBestFormatter(String propertyName, Class<? extends BusinessObject> boClass) {

                 Formatter formatter = null;

                 try {

                         Class<? extends Formatter> formatterClass = null;

                         final BusinessObjectEntry boEntry = getBusinessObjectEntry(boClass);

                         if (boEntry != null) {

                                 final AttributeDefinition attributeDefinition = boEntry.getAttributeDefinition(propertyName);

                                 if (attributeDefinition != null && attributeDefinition.hasFormatterClass()) {

                                         formatterClass = (Class<? extends Formatter>)Class.forName(attributeDefinition.getFormatterClass());

                                 }

                         }

                         if (formatterClass == null) {

                                 final java.lang.reflect.Field propertyField = boClass.getDeclaredField(propertyName);

                                 if (propertyField != null) {

                                         formatterClass = Formatter.findFormatter(propertyField.getType());

                                 }

                         }

                         if (formatterClass != null) {

                                 formatter = formatterClass.newInstance();

                         }

                 } catch (SecurityException se) {

                         throw new RuntimeException("Could not retrieve good formatter", se);

                 } catch (ClassNotFoundException cnfe) {

                         throw new RuntimeException("Could not retrieve good formatter", cnfe);

                 } catch (NoSuchFieldException nsfe) {

                         throw new RuntimeException("Could not retrieve good formatter", nsfe);

                 } catch (IllegalAccessException iae) {

                         throw new RuntimeException("Could not retrieve good formatter", iae);

                 } catch (InstantiationException ie) {

                         throw new RuntimeException("Could not retrieve good formatter", ie);

                 }

                 return formatter;

         }

         /**

          * Looks up the DataDictionary BusinessObjectEntry for the given class

          * 

          * @param boClass the class of the BusinessObject to find a BusinessObjectEntry for

          * @return the entry from the data dictionary, or null if nothing was found

          */

         protected BusinessObjectEntry getBusinessObjectEntry(Class<? extends BusinessObject> boClass) {

                 return getDataDictionaryService().getDataDictionary().getBusinessObjectEntry(boClass.getName());

         }

         /**

          * @return the dataDictionaryService

          */

         public DataDictionaryService getDataDictionaryService() {

                 return this.dataDictionaryService;

         }

         /**

          * @param dataDictionaryService the dataDictionaryService to set

          */

         public void setDataDictionaryService(DataDictionaryService dataDictionaryService) {

                 this.dataDictionaryService = dataDictionaryService;

         }

 }