/*

  * Copyright 2005-2008 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.service.impl;

 import java.beans.PropertyDescriptor;

 import java.io.IOException;

 import java.io.InputStream;

 import java.lang.reflect.InvocationTargetException;

 import java.util.HashMap;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 import java.util.Vector;

 import org.apache.commons.beanutils.PropertyUtils;

 import org.apache.commons.lang.StringUtils;

 import org.apache.log4j.Logger;

 import org.apache.ojb.broker.metadata.ClassDescriptor;

 import org.apache.ojb.broker.metadata.ConnectionRepository;

 import org.apache.ojb.broker.metadata.DescriptorRepository;

 import org.apache.ojb.broker.metadata.FieldDescriptor;

 import org.apache.ojb.broker.metadata.MetadataManager;

 import org.apache.ojb.broker.metadata.ObjectReferenceDescriptor;

 import org.apache.ojb.broker.metadata.fieldaccess.PersistentField;

 import org.kuali.rice.core.exception.RiceRuntimeException;

 import org.kuali.rice.core.util.ClassLoaderUtils;

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

 import org.kuali.rice.kns.dao.PersistenceDao;

 import org.kuali.rice.kns.exception.IntrospectionException;

 import org.kuali.rice.kns.exception.ObjectNotABusinessObjectRuntimeException;

 import org.kuali.rice.kns.exception.ReferenceAttributeDoesntExistException;

 import org.kuali.rice.kns.exception.ReferenceAttributeNotAnOjbReferenceException;

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

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

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

 import org.springframework.core.io.DefaultResourceLoader;

 import org.springframework.transaction.annotation.Transactional;

 /**

  * This class is the service implementation for the Persistence structure.

  * OjbRepositoryExplorer provides functions for extracting information from the

  * OJB repository at runtime. This is the default implementation, that is

  * delivered with Kuali.

  */

 @Transactional

 public class PersistenceServiceOjbImpl extends PersistenceServiceImplBase implements PersistenceService {

     private static Logger LOG = Logger.getLogger(PersistenceServiceOjbImpl.class);

     private static final String CLASSPATH_RESOURCE_PREFIX = "classpath:";

     private PersistenceDao persistenceDao;

     public void clearCache() {

         persistenceDao.clearCache();

     }

     public Object resolveProxy(Object o) {

         return persistenceDao.resolveProxy(o);

     }

         public void loadRepositoryDescriptor(String ojbRepositoryFilePath) {

                 if ( LOG.isInfoEnabled() ) {

                         LOG.info("Begin loading OJB Metadata for: " + ojbRepositoryFilePath);

                 }

                 DefaultResourceLoader resourceLoader = new DefaultResourceLoader(ClassLoaderUtils.getDefaultClassLoader());

                 InputStream is = null;

                 try {

                         is = resourceLoader.getResource(CLASSPATH_RESOURCE_PREFIX + ojbRepositoryFilePath).getInputStream();

                         ConnectionRepository cr = MetadataManager.getInstance().readConnectionRepository(is);

                         MetadataManager.getInstance().mergeConnectionRepository(cr);

                         is = resourceLoader.getResource(CLASSPATH_RESOURCE_PREFIX + ojbRepositoryFilePath).getInputStream();

                         DescriptorRepository dr = MetadataManager.getInstance().readDescriptorRepository(is);

                         MetadataManager.getInstance().mergeDescriptorRepository(dr);

                         if (LOG.isDebugEnabled()) {

                                 LOG.debug("--------------------------------------------------------------------------");

                                 LOG.debug("Merging repository descriptor: " + ojbRepositoryFilePath);

                                 LOG.debug("--------------------------------------------------------------------------");

                         }

                 } catch (IOException ioe) {

                         if (is != null) {

                                 try {

                                         is.close();

                                 } catch (IOException e) {

                                         LOG.warn("Failed to close InputStream on OJB repository path " + ojbRepositoryFilePath, e);

                                 }

                         }

                         throw new RiceRuntimeException(ioe);

                 } finally {

                         if (is != null) {

                                 try {

                                         is.close();

                                 } catch (IOException e) {

                                         LOG.warn("Failed to close InputStream on OJB repository path " + ojbRepositoryFilePath, e);

                                 }

                         }

                 }

                 if ( LOG.isInfoEnabled() ) {

                         LOG.info("Finished loading OJB Metadata for: " + ojbRepositoryFilePath);

                 }

         }

     /**

          * @see org.kuali.rice.kns.service.PersistenceService#retrieveNonKeyFields(java.lang.Object)

          */

     public void retrieveNonKeyFields(Object persistableObject) {

         if (persistableObject == null) {

             throw new IllegalArgumentException("invalid (null) persistableObject");

         }

         if ( LOG.isDebugEnabled() ) {

                 LOG.debug("retrieving non-key fields for " + persistableObject);

         }

         persistenceDao.retrieveAllReferences(persistableObject);

     }

     /**

          * @see org.kuali.rice.kns.service.PersistenceService#retrieveReferenceObject(java.lang.Object,

          *      String referenceObjectName)

      */

     public void retrieveReferenceObject(Object persistableObject, String referenceObjectName) {

         if (persistableObject == null) {

             throw new IllegalArgumentException("invalid (null) persistableObject");

         }

         if ( LOG.isDebugEnabled() ) {

                 LOG.debug("retrieving reference object " + referenceObjectName + " for " + persistableObject);

         }

         persistenceDao.retrieveReference(persistableObject, referenceObjectName);

     }

     /**

          * @see org.kuali.rice.kns.service.PersistenceService#retrieveReferenceObject(java.lang.Object,

          *      String referenceObjectName)

      */

     public void retrieveReferenceObjects(Object persistableObject, List referenceObjectNames) {

         if (persistableObject == null) {

             throw new IllegalArgumentException("invalid (null) persistableObject");

         }

         if (referenceObjectNames == null) {

             throw new IllegalArgumentException("invalid (null) referenceObjectNames");

         }

         if (referenceObjectNames.isEmpty()) {

             throw new IllegalArgumentException("invalid (empty) referenceObjectNames");

         }

         int index = 0;

         for (Iterator i = referenceObjectNames.iterator(); i.hasNext(); index++) {

             String referenceObjectName = (String) i.next();

             if (StringUtils.isBlank(referenceObjectName)) {

                 throw new IllegalArgumentException("invalid (blank) name at position " + index);

             }

             retrieveReferenceObject(persistableObject, referenceObjectName);

         }

     }

     /**

          * @see org.kuali.rice.kns.service.PersistenceService#retrieveReferenceObject(java.lang.Object,

          *      String referenceObjectName)

      */

     public void retrieveReferenceObjects(List persistableObjects, List referenceObjectNames) {

         if (persistableObjects == null) {

             throw new IllegalArgumentException("invalid (null) persistableObjects");

         }

         if (persistableObjects.isEmpty()) {

             throw new IllegalArgumentException("invalid (empty) persistableObjects");

         }

         if (referenceObjectNames == null) {

             throw new IllegalArgumentException("invalid (null) referenceObjectNames");

         }

         if (referenceObjectNames.isEmpty()) {

             throw new IllegalArgumentException("invalid (empty) referenceObjectNames");

         }

         for (Iterator i = persistableObjects.iterator(); i.hasNext();) {

             Object persistableObject = i.next();

             retrieveReferenceObjects(persistableObject, referenceObjectNames);

         }

     }

     /**

      * @see org.kuali.rice.kns.service.PersistenceService#getFlattenedPrimaryKeyFieldValues(java.lang.Object)

      */

     public String getFlattenedPrimaryKeyFieldValues(Object persistableObject) {

         if (persistableObject == null) {

             throw new IllegalArgumentException("invalid (null) persistableObject");

         }

         Map primaryKeyValues = getPrimaryKeyFieldValues(persistableObject, true);

         StringBuffer flattened = new StringBuffer(persistableObject.getClass().getName());

         flattened.append("(");

         for (Iterator i = primaryKeyValues.entrySet().iterator(); i.hasNext();) {

             Map.Entry e = (Map.Entry) i.next();

             String fieldName = (String) e.getKey();

             Object fieldValue = e.getValue();

             flattened.append(fieldName + "=" + fieldValue);

             if (i.hasNext()) {

                 flattened.append(",");

             }

         }

         flattened.append(")");

         return flattened.toString();

     }

     private void linkObjectsWithCircularReferenceCheck(Object persistableObject, Set referenceSet) {

         if (ObjectUtils.isNull(persistableObject) || referenceSet.contains(persistableObject)) {

             return;

         }

         referenceSet.add(persistableObject);

         ClassDescriptor classDescriptor = getClassDescriptor(persistableObject.getClass());

         String className = null;

         String fieldName = null;

         try {

             // iterate through all object references for the persistableObject

             Vector objectReferences = classDescriptor.getObjectReferenceDescriptors();

             for (Iterator iter = objectReferences.iterator(); iter.hasNext();) {

                 ObjectReferenceDescriptor referenceDescriptor = (ObjectReferenceDescriptor) iter.next();

                 // get the actual reference object

                 className = persistableObject.getClass().getName();

                 fieldName = referenceDescriptor.getAttributeName();

                 Object referenceObject = PropertyUtils.getProperty(persistableObject, fieldName);

                 if (ObjectUtils.isNull(referenceObject) || referenceSet.contains(referenceObject)) {

                     continue;

                 }

                 // recursively link object

                 linkObjectsWithCircularReferenceCheck(referenceObject, referenceSet);

                                 // iterate through the keys for the reference object and set

                                 // value

                 FieldDescriptor[] refFkNames = referenceDescriptor.getForeignKeyFieldDescriptors(classDescriptor);

                 ClassDescriptor refCld = getClassDescriptor(referenceDescriptor.getItemClass());

                 FieldDescriptor[] refPkNames = refCld.getPkFields();

                 Map objFkValues = new HashMap();

                 for (int i = 0; i < refPkNames.length; i++) {

                     objFkValues.put(refFkNames[i].getAttributeName(), ObjectUtils.getPropertyValue(referenceObject, refPkNames[i].getAttributeName()));

                 }

                 for (int i = 0; i < refFkNames.length; i++) {

                     FieldDescriptor fkField = refFkNames[i];

                     String fkName = fkField.getAttributeName();

                                         // if the fk from object and use if main object does not

                                         // have value

                     Object fkValue = null;

                     if (objFkValues.containsKey(fkName)) {

                         fkValue = objFkValues.get(fkName);

                     }

                     // if fk is set in main object, take value from there

                     Object mainFkValue = ObjectUtils.getPropertyValue(persistableObject, fkName);

                     if (ObjectUtils.isNotNull(mainFkValue) && StringUtils.isNotBlank(mainFkValue.toString())) {

                         fkValue = mainFkValue;

                                         } else if (ObjectUtils.isNull(fkValue) || StringUtils.isBlank(fkValue.toString())) {

                                                 // find the value from one of the other reference

                                                 // objects

                         for (Iterator iter2 = objectReferences.iterator(); iter2.hasNext();) {

                             ObjectReferenceDescriptor checkDescriptor = (ObjectReferenceDescriptor) iter2.next();

                             fkValue = getReferenceFKValue(persistableObject, checkDescriptor, fkName);

                             if (ObjectUtils.isNotNull(fkValue) && StringUtils.isNotBlank(fkValue.toString())) {

                                 break;

                             }

                         }

                     }

                     // set the fk value

                     if (ObjectUtils.isNotNull(fkValue)) {

                         fieldName = refPkNames[i].getAttributeName();

                         ObjectUtils.setObjectProperty(referenceObject, fieldName, fkValue.getClass(), fkValue);

                         // set fk in main object

                         if (ObjectUtils.isNull(mainFkValue)) {

                             ObjectUtils.setObjectProperty(persistableObject, fkName, fkValue.getClass(), fkValue);

                         }

                     }

                 }

             }

                 } catch (NoSuchMethodException e) {

             throw new IntrospectionException("no setter for property '" + className + "." + fieldName + "'", e);

                 } catch (IllegalAccessException e) {

             throw new IntrospectionException("problem accessing property '" + className + "." + fieldName + "'", e);

                 } catch (InvocationTargetException e) {

             throw new IntrospectionException("problem invoking getter for property '" + className + "." + fieldName + "'", e);

         }

     }

     /**

          * For each reference object to the parent persistableObject, sets the key

          * values for that object. First, if the reference object already has a

          * value for the key, the value is left unchanged. Otherwise, for

          * non-anonymous keys, the value is taken from the parent object. For

          * anonymous keys, all other persistableObjects are checked until a value

          * for the key is found.

      * 

      * @see org.kuali.rice.kns.service.PersistenceService#getReferencedObject(java.lang.Object,

      *      org.apache.ojb.broker.metadata.ObjectReferenceDescriptor)

      */

     public void linkObjects(Object persistableObject) {

         linkObjectsWithCircularReferenceCheck(persistableObject, new HashSet());

     }

     /**

      * 

      * @see org.kuali.rice.kns.service.PersistenceService#allForeignKeyValuesPopulatedForReference(org.kuali.rice.kns.bo.BusinessObject,

      *      java.lang.String)

      */

     public boolean allForeignKeyValuesPopulatedForReference(PersistableBusinessObject bo, String referenceName) {

         boolean allFkeysHaveValues = true;

         // yelp if nulls were passed in

         if (bo == null) {

             throw new IllegalArgumentException("The Class passed in for the BusinessObject argument was null.");

         }

         if (StringUtils.isBlank(referenceName)) {

             throw new IllegalArgumentException("The String passed in for the referenceName argument was null or empty.");

         }

         PropertyDescriptor propertyDescriptor = null;

         // make sure the attribute exists at all, throw exception if not

         try {

             propertyDescriptor = PropertyUtils.getPropertyDescriptor(bo, referenceName);

                 } catch (Exception e) {

             throw new RuntimeException(e);

         }

         if (propertyDescriptor == null) {

             throw new ReferenceAttributeDoesntExistException("Requested attribute: '" + referenceName + "' does not exist " + "on class: '" + bo.getClass().getName() + "'.");

         }

         // get the class of the attribute name

         Class referenceClass = getBusinessObjectAttributeClass( bo.getClass(), referenceName );

         if ( referenceClass == null ) {

                 referenceClass = propertyDescriptor.getPropertyType();

         }

         // make sure the class of the attribute descends from BusinessObject,

         // otherwise throw an exception

         if (!PersistableBusinessObject.class.isAssignableFrom(referenceClass)) {

                         throw new ObjectNotABusinessObjectRuntimeException("Attribute requested (" + referenceName + ") is of class: " + "'" + referenceClass.getName() + "' and is not a " + "descendent of BusinessObject.  Only descendents of BusinessObject "

                                         + "can be used.");

         }

                 // make sure the attribute designated is listed as a

                 // reference-descriptor

                 // on the clazz specified, otherwise throw an exception (OJB);

         ClassDescriptor classDescriptor = getClassDescriptor(bo.getClass());

         ObjectReferenceDescriptor referenceDescriptor = classDescriptor.getObjectReferenceDescriptorByName(referenceName);

         if (referenceDescriptor == null) {

             throw new ReferenceAttributeNotAnOjbReferenceException("Attribute requested (" + referenceName + ") is not listed " + "in OJB as a reference-descriptor for class: '" + bo.getClass().getName() + "'");

         }

                 // get the list of the foreign-keys for this reference-descriptor

                 // (OJB)

         Vector fkFields = referenceDescriptor.getForeignKeyFields();

         Iterator fkIterator = fkFields.iterator();

         // walk through the list of the foreign keys, get their types

         while (fkIterator.hasNext()) {

             // get the field name of the fk & pk field

             String fkFieldName = (String) fkIterator.next();

             // get the value for the fk field

             Object fkFieldValue = null;

             try {

                 fkFieldValue = PropertyUtils.getSimpleProperty(bo, fkFieldName);

             }

             // if we cant retrieve the field value, then

             // it doesnt have a value

             catch (IllegalAccessException e) {

                 return false;

                         } catch (InvocationTargetException e) {

                 return false;

                         } catch (NoSuchMethodException e) {

                 return false;

             }

             // test the value

             if (fkFieldValue == null) {

                 return false;

                         } else if (String.class.isAssignableFrom(fkFieldValue.getClass())) {

                 if (StringUtils.isBlank((String) fkFieldValue)) {

                     return false;

                 }

             }

         }

         return allFkeysHaveValues;

     }

     /**

      * 

      * @see org.kuali.rice.kns.service.PersistenceService#refreshAllNonUpdatingReferences(org.kuali.rice.kns.bo.BusinessObject)

      */

     public void refreshAllNonUpdatingReferences(PersistableBusinessObject bo) {

         // get the OJB class-descriptor for the bo class

         ClassDescriptor classDescriptor = getClassDescriptor(bo.getClass());

         // get a list of all reference-descriptors for that class

         Vector references = classDescriptor.getObjectReferenceDescriptors();

         // walk through all of the reference-descriptors

         for (Iterator iter = references.iterator(); iter.hasNext();) {

             ObjectReferenceDescriptor reference = (ObjectReferenceDescriptor) iter.next();

             // if its NOT an updateable reference, then lets refresh it

             if (reference.getCascadingStore() == ObjectReferenceDescriptor.CASCADE_NONE) {

                 PersistentField persistentField = reference.getPersistentField();

                 String referenceName = persistentField.getName();

                 retrieveReferenceObject(bo, referenceName);

             }

         }

     }

     private Object getReferenceFKValue(Object persistableObject, ObjectReferenceDescriptor chkRefCld, String fkName) {

         ClassDescriptor classDescriptor = getClassDescriptor(persistableObject.getClass());

         Object referenceObject = ObjectUtils.getPropertyValue(persistableObject, chkRefCld.getAttributeName());

         if (referenceObject == null) {

             return null;

         }

         FieldDescriptor[] refFkNames = chkRefCld.getForeignKeyFieldDescriptors(classDescriptor);

         ClassDescriptor refCld = getClassDescriptor(chkRefCld.getItemClass());

         FieldDescriptor[] refPkNames = refCld.getPkFields();

         Object fkValue = null;

         for (int i = 0; i < refFkNames.length; i++) {

             FieldDescriptor fkField = refFkNames[i];

             if (fkField.getAttributeName().equals(fkName)) {

                 fkValue = ObjectUtils.getPropertyValue(referenceObject, refPkNames[i].getAttributeName());

                 break;

             }

         }

         return fkValue;

     }

     /**

      * Sets the persistenceDao attribute value.

          * 

          * @param persistenceDao

          *            The persistenceDao to set.

      */

     public void setPersistenceDao(PersistenceDao persistenceDao) {

         this.persistenceDao = persistenceDao;

     }

 }