package org.apache.ojb.broker.core;

 /* Copyright 2002-2005 The Apache Software Foundation

  *

  * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0

  *

  * 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.

  */

 import java.util.Map;

 import org.apache.ojb.broker.Identity;

 import org.apache.ojb.broker.IdentityFactory;

 import org.apache.ojb.broker.OJBRuntimeException;

 import org.apache.ojb.broker.PersistenceBroker;

 import org.apache.ojb.broker.PersistenceBrokerException;

 import org.apache.ojb.broker.PBStateListener;

 import org.apache.ojb.broker.PBStateEvent;

 import org.apache.ojb.broker.core.proxy.IndirectionHandler;

 import org.apache.ojb.broker.core.proxy.ProxyHelper;

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

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

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

 import org.apache.ojb.broker.util.BrokerHelper;

 import org.apache.ojb.broker.util.sequence.SequenceManager;

 import org.apache.ojb.broker.util.sequence.SequenceManagerTransientImpl;

 import org.apache.commons.lang.SystemUtils;

 import org.apache.commons.lang.ArrayUtils;

 import org.apache.commons.lang.exception.ExceptionUtils;

 import org.apache.commons.collections.map.ReferenceIdentityMap;

 /**

  * @author <a href="mailto:armin@codeAuLait.de">Armin Waibel</a>

  * @version $Id: IdentityFactoryImpl.java,v 1.1 2007-08-24 22:17:35 ewestfal Exp $

  * @see org.apache.ojb.broker.IdentityFactory

  */

 public class IdentityFactoryImpl implements IdentityFactory, PBStateListener

 {

     private PersistenceBroker broker;

     //private boolean activeTx;

     private Map objectToIdentityMap;

     private SequenceManager transientSequenceManager;

     public IdentityFactoryImpl(PersistenceBroker broker)

     {

         this.broker = broker;

         this.objectToIdentityMap = new ReferenceIdentityMap(ReferenceIdentityMap.WEAK, ReferenceIdentityMap.HARD, true);

         this.transientSequenceManager = new SequenceManagerTransientImpl(broker);

         broker.addListener(this, true);

     }

     /**

      * This methods creates a new transient (if at least one PK field is 'null') or persistent

      * (if the PK fields are populated) {@link org.apache.ojb.broker.Identity} instance. If the specified object

      * is transient and former call for the same object returns already a transient Identity, the same transient

      * Identity object will be returned.

      */

     protected Identity createTransientOrRealIdentity(ClassDescriptor cld, Object objOrProxy)

     {

         if(objOrProxy == null) throw new OJBRuntimeException("Can't create Identity for 'null'-object");

         Identity result = null;

         Class topLevelClass = null;

         Class realClass = null;

         Object[] pks = null;

         try

         {

             final IndirectionHandler handler = ProxyHelper.getIndirectionHandler(objOrProxy);

             synchronized(objOrProxy)

             {

                 if(handler != null)

                 {

                     result = handler.getIdentity();

                 }

                 else

                 {

                     // now we are sure that the specified object is not a proxy

                     realClass = objOrProxy.getClass();

                     topLevelClass = broker.getTopLevelClass(objOrProxy.getClass());

                     if(cld == null)

                     {

                         cld = broker.getClassDescriptor(objOrProxy.getClass());

                     }

                     BrokerHelper helper = broker.serviceBrokerHelper();

                     FieldDescriptor[] fields = cld.getPkFields();

                     pks = new Object[fields.length];

                     FieldDescriptor fld;

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

                     {

                         fld = fields[i];

                         /*

                         we check all PK fields for 'null'-values

                         */

                         Object value = fld.getPersistentField().get(objOrProxy);

                         if(helper.representsNull(fld, value))

                         {

                             result = (Identity) objectToIdentityMap.get(objOrProxy);

                             if(result == null)

                             {

                                 pks[i] = transientSequenceManager.getUniqueValue(fld);

                                 result = new Identity(realClass, topLevelClass, pks, true);

                                 //if(activeTx) objectToIdentityMap.put(objOrProxy, result);

                                 objectToIdentityMap.put(objOrProxy, result);

                             }

                             break;

                         }

                         else

                         {

                             pks[i] = value;

                         }

                     }

                     if(result == null)

                     {

                         result = new Identity(realClass, topLevelClass, pks, false);

                     }

                 }

             }

         }

         catch(ClassNotPersistenceCapableException e)

         {

             throw e;

         }

         catch(Exception e)

         {

             throw createException(e, "Can not init Identity for given object.", objOrProxy, topLevelClass, realClass, pks);

         }

         return result;

     }

     /** @see org.apache.ojb.broker.IdentityFactory#buildIdentity(Object) */

     public Identity buildIdentity(Object obj)

     {

         return createTransientOrRealIdentity(broker.getClassDescriptor(ProxyHelper.getRealClass(obj)), obj);

     }

     /** @see org.apache.ojb.broker.IdentityFactory#buildIdentity(Object) */

     public Identity buildIdentity(ClassDescriptor cld, Object obj)

     {

         return createTransientOrRealIdentity(cld, obj);

     }

     /** @see org.apache.ojb.broker.IdentityFactory#buildIdentity(Class, Class, String[], Object[]) */

     public Identity buildIdentity(Class realClass, Class topLevelClass, String[] pkFieldNames, Object[] pkValues)

     {

         Object[] orderedPKValues = pkValues;

         if(pkValues == null)

         {

             throw new NullPointerException("Given primary key value array can't be null");

         }

         if(pkValues.length == 1 && (pkFieldNames == null || pkFieldNames.length == 1))

         {

             /*

             we assume only a single PK field is defined and do no further checks,

             we have nothing to do

             */

         }

         else

         {

             // in other more complex cases we do several check

             FieldDescriptor[] flds = broker.getClassDescriptor(realClass).getPkFields();

             if(!isOrdered(flds, pkFieldNames))

             {

                 orderedPKValues = reorderFieldValues(flds, pkFieldNames, pkValues);

             }

         }

         return new Identity(realClass, topLevelClass, orderedPKValues);

     }

     /**

      * This method orders the specified field values based on the

      * specified {@link org.apache.ojb.broker.metadata.FieldDescriptor}.

      *

      * @param flds The {@link org.apache.ojb.broker.metadata.FieldDescriptor} array.

      * @param fieldNames The field names.

      * @param fieldValues The field values.

      * @return The ordered field values.

      */

     private Object[] reorderFieldValues(FieldDescriptor[] flds, String[] fieldNames, Object[] fieldValues)

     {

         String fieldName;

         Object[] orderedValues = new Object[flds.length];

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

         {

             fieldName = flds[i].getPersistentField().getName();

             int realPosition = findIndexForName(fieldNames, fieldName);

             orderedValues[i] = fieldValues[realPosition];

         }

         return orderedValues;

     }

     /**

      * Find the index of the specified name in field name array.

      */

     private int findIndexForName(String[] fieldNames, String searchName)

     {

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

         {

             if(searchName.equals(fieldNames[i]))

             {

                 return i;

             }

         }

         throw new PersistenceBrokerException("Can't find field name '" + searchName +

                 "' in given array of field names");

     }

     /** Checks length and compare order of field names with declared PK fields in metadata. */

     private boolean isOrdered(FieldDescriptor[] flds, String[] pkFieldNames)

     {

         if((flds.length > 1 && pkFieldNames == null) || flds.length != pkFieldNames.length)

         {

             throw new PersistenceBrokerException("pkFieldName length does not match number of defined PK fields." +

                     " Expected number of PK fields is " + flds.length + ", given number was " +

                     (pkFieldNames != null ? pkFieldNames.length : 0));

         }

         boolean result = true;

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

         {

             FieldDescriptor fld = flds[i];

             result = result && fld.getPersistentField().getName().equals(pkFieldNames[i]);

         }

         return result;

     }

     /** @see org.apache.ojb.broker.IdentityFactory#buildIdentity(Class, String[], Object[]) */

     public Identity buildIdentity(Class realClass, String[] pkFieldNames, Object[] pkValues)

     {

         return buildIdentity(realClass, broker.getTopLevelClass(realClass), pkFieldNames, pkValues);

     }

     /** @see org.apache.ojb.broker.IdentityFactory#buildIdentity(Class, String[], Object[]) */

     public Identity buildIdentity(Class realClass, Class topLevelClass, Object[] pkValues)

     {

         return new Identity(realClass, topLevelClass, pkValues);

     }

     /** @see org.apache.ojb.broker.IdentityFactory#buildIdentity(Class, Object) */

     public Identity buildIdentity(Class realClass, Object pkValue)

     {

         return buildIdentity(realClass, (String[]) null, new Object[]{pkValue});

     }

     /**

      * Helper method which supports creation of proper error messages.

      *

      * @param ex An exception to include or <em>null</em>.

      * @param message The error message or <em>null</em>.

      * @param objectToIdentify The current used object or <em>null</em>.

      * @param topLevelClass The object top-level class or <em>null</em>.

      * @param realClass The object real class or <em>null</em>.

      * @param pks The associated PK values of the object or <em>null</em>.

      * @return The generated exception.

      */

     private PersistenceBrokerException createException(final Exception ex, String message, final Object objectToIdentify, Class topLevelClass, Class realClass, Object[] pks)

     {

         final String eol = SystemUtils.LINE_SEPARATOR;

         StringBuffer msg = new StringBuffer();

         if(message == null)

         {

             msg.append("Unexpected error: ");

         }

         else

         {

             msg.append(message).append(" :");

         }

         if(topLevelClass != null) msg.append(eol).append("objectTopLevelClass=").append(topLevelClass.getName());

         if(realClass != null) msg.append(eol).append("objectRealClass=").append(realClass.getName());

         if(pks != null) msg.append(eol).append("pkValues=").append(ArrayUtils.toString(pks));

         if(objectToIdentify != null) msg.append(eol).append("object to identify: ").append(objectToIdentify);

         if(ex != null)

         {

             // add causing stack trace

             Throwable rootCause = ExceptionUtils.getRootCause(ex);

             if(rootCause != null)

             {

                 msg.append(eol).append("The root stack trace is --> ");

                 String rootStack = ExceptionUtils.getStackTrace(rootCause);

                 msg.append(eol).append(rootStack);

             }

             return new PersistenceBrokerException(msg.toString(), ex);

         }

         else

         {

             return new PersistenceBrokerException(msg.toString());

         }

     }

     //===================================================================

     // PBStateListener interface

     //===================================================================

     public void afterBegin(PBStateEvent event)

     {

     }

     public void afterCommit(PBStateEvent event)

     {

         if(objectToIdentityMap.size() > 0) objectToIdentityMap.clear();

     }

     public void afterRollback(PBStateEvent event)

     {

         if(objectToIdentityMap.size() > 0) objectToIdentityMap.clear();

     }

     public void beforeClose(PBStateEvent event)

     {

         if(objectToIdentityMap.size() > 0) objectToIdentityMap.clear();

     }

     public void beforeRollback(PBStateEvent event)

     {

     }

     public void afterOpen(PBStateEvent event)

     {

     }

     public void beforeBegin(PBStateEvent event)

     {

     }

     public void beforeCommit(PBStateEvent event)

     {

     }

 }