package org.apache.ojb.broker.metadata;

 /* 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.ArrayList;

 import java.util.Collection;

 import java.util.Iterator;

 import java.util.Vector;

 import org.apache.commons.lang.SystemUtils;

 import org.apache.ojb.broker.PersistenceBrokerException;

 import org.apache.ojb.broker.accesslayer.QueryCustomizer;

 /**

  * mapping Description for member fields that are Collections

  * <br>

  * Note: Be careful when use references of this class or caching instances of this class,

  * because instances could become invalid (see {@link MetadataManager}).

  *

  * @author <a href="mailto:thma@apache.org">Thomas Mahler<a>

  * @version $Id: CollectionDescriptor.java,v 1.1 2007-08-24 22:17:29 ewestfal Exp $

  */

 public class CollectionDescriptor extends ObjectReferenceDescriptor

 {

     private static final long serialVersionUID = -8570280662286424937L;

     /**

      * Represents the type of the collection, if set to null,

      * a java.util.Vector will be used.

      * If set to a valid collection type it will be used to build typed collections.

      */

     private Class collectionClass = null;

     /**

      * the Collection of orderby Fields

      */

     private Collection m_orderby = new ArrayList();

     /**

      * For m:n related Classes this is the indirection table.

      */

     private String indirectionTable = null;

     private Vector fksToItemClass = null;

     private Vector fksToThisClass = null;

     private String[] fksToItemClassAry;

     private String[] fksToThisClassAry;

     private QueryCustomizer m_queryCustomizer;

     private Boolean m_hasProxyItems;

     public CollectionDescriptor(ClassDescriptor descriptor)

     {

         super(descriptor);

     }

     public String[] getFksToThisClass()

     {

         if (fksToThisClassAry == null)

         {

             fksToThisClassAry = (String[]) fksToThisClass.toArray(

                     new String[fksToThisClass.size()]);

         }

         return fksToThisClassAry;

     }

     public void setFksToThisClass(Vector fksToThisClass)

     {

         this.fksToThisClass = fksToThisClass;

         fksToThisClassAry = null;

     }

     /**

      * add a FK column pointing to This Class

      */

     public void addFkToThisClass(String column)

     {

         if (fksToThisClass == null)

         {

             fksToThisClass = new Vector();

         }

         fksToThisClass.add(column);

         fksToThisClassAry = null;

     }

     /**

      * add a FK column pointing to the item Class

      */

     public void addFkToItemClass(String column)

     {

         if (fksToItemClass == null)

         {

             fksToItemClass = new Vector();

         }

         fksToItemClass.add(column);

         fksToItemClassAry = null;

     }

     /**

      * returns the type of the collection.

      * @return java.lang.Class

      */

     public Class getCollectionClass()

     {

         return collectionClass;

     }

     /**

      * set the type of the collection

      * @param c the collection type

      */

     public void setCollectionClass(Class c)

     {

         collectionClass = c;

     }

     /**

      * Retrieve the classname of the collection.

      */

     public String getCollectionClassName()

     {

         return collectionClass != null ? collectionClass.getName() : null;

     }

     public String getIndirectionTable()

     {

         return indirectionTable;

     }

     public void setIndirectionTable(String indirectionTable)

     {

         this.indirectionTable = indirectionTable;

     }

     public String[] getFksToItemClass()

     {

         if (fksToItemClassAry == null)

         {

             fksToItemClassAry = (String[]) fksToItemClass.toArray(

                     new String[fksToItemClass.size()]);

         }

         return fksToItemClassAry;

     }

     public void setFksToItemClass(Vector fksToItemClass)

     {

         this.fksToItemClass = fksToItemClass;

         fksToItemClassAry = null;

     }

     public boolean isMtoNRelation()

     {

         return (indirectionTable != null);

     }

     /**

      * Adds a field for orderBy

      * @param  fieldName    The field name to be used

      * @param  sortAscending    true for ASCENDING, false for DESCENDING

      */

     public void addOrderBy(String fieldName, boolean sortAscending)

     {

         if (fieldName != null)

         {

             m_orderby.add(new FieldHelper(fieldName, sortAscending));

         }

     }

     /**

      * Returns the orderby Collection of Fields.

      * @return Collection

      */

     public Collection getOrderBy()

     {

         return m_orderby;

     }

     protected int getCascadeDeleteValue(String cascade)

     {

         if(cascade.equalsIgnoreCase("false") && isMtoNRelation())

         {

             /*

             "old" implementation does always delete entries in indirection table for

             m:n relations. For 1:n relations referenced objects are not touched.

             */

             return CASCADE_LINK;

         }

         return super.getCascadeDeleteValue(cascade);

     }

     /*

      * @see XmlCapable#toXML()

      */

     public String toXML()

     {

         RepositoryTags tags = RepositoryTags.getInstance();

         String eol = SystemUtils.LINE_SEPARATOR;

         // write opening tag

         String result = "      " + tags.getOpeningTagNonClosingById(COLLECTION_DESCRIPTOR) + eol;

         // write attributes

         // name

         result       += "        " + tags.getAttribute(FIELD_NAME,this.getAttributeName()) + eol;

         // collection class is optional

         if (getCollectionClassName() != null)

         {

             result       += "        " + tags.getAttribute(COLLECTION_CLASS,this.getCollectionClassName()) + eol;

         }

         // element-class-ref

          result       += "        " + tags.getAttribute(ITEMS_CLASS,this.getItemClassName()) + eol;

         // indirection-table is optional

         if (isMtoNRelation())

         {

              result += "        " + tags.getAttribute(INDIRECTION_TABLE,getIndirectionTable()) + eol;

         }

         // proxyReference is optional, disabled by default

         if (isLazy())

         {

             result       += "        " + tags.getAttribute(PROXY_REFERENCE,"true") + eol;

             result       += "        " + tags.getAttribute(PROXY_PREFETCHING_LIMIT, "" + this.getProxyPrefetchingLimit()) + eol;

         }

         //reference refresh is optional, disabled by default

         if (isRefresh())

         {

              result       += "        " + tags.getAttribute(REFRESH,"true") + eol;

         }

         //auto retrieve

         result += "        " + tags.getAttribute(AUTO_RETRIEVE, "" + getCascadeRetrieve()) + eol;

         //auto update

         result += "        " + tags.getAttribute(AUTO_UPDATE, getCascadeAsString(getCascadingStore())) + eol;

         //auto delete

         result += "        " + tags.getAttribute(AUTO_DELETE, getCascadeAsString(getCascadingDelete())) + eol;

         //otm-dependent is optional, disabled by default

         if (getOtmDependent())

         {

             result += "        " + tags.getAttribute(OTM_DEPENDENT, "true") + eol;

         }

         // close opening tag

         result       += "      >" + eol;

         // write elements

          // inverse fk elements

         for (int i=0;i<getForeignKeyFields().size();i++)

         {

         Object obj = getForeignKeyFields().get(i);

         if (obj instanceof Integer)

         {

                 String fkId = obj.toString();

             result += "        " + tags.getOpeningTagNonClosingById(INVERSE_FK) + " ";

                 result += tags.getAttribute(FIELD_ID_REF, fkId) + "/>" + eol;

         }

         else

         {

                 String fk = (String) obj;

             result += "        " + tags.getOpeningTagNonClosingById(INVERSE_FK) + " ";

                 result += tags.getAttribute(FIELD_REF, fk) + "/>" + eol;

         }

         }

         // write optional M:N elements

         // m:n relationship settings, optional

         if (isMtoNRelation())

         {

             // foreign keys to this class

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

              {

                 String fkId = getFksToThisClass()[i];

                 result += "        " + tags.getOpeningTagNonClosingById(FK_POINTING_TO_THIS_CLASS) + " ";

                 result += tags.getAttribute(COLUMN_NAME, fkId) + "/>" + eol;

              }

             // foreign keys to item class

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

              {

                 String fkId = getFksToItemClass()[i];

                 result += "        " + tags.getOpeningTagNonClosingById(FK_POINTING_TO_ITEMS_CLASS) + " ";

                 result += tags.getAttribute(COLUMN_NAME, fkId) + "/>" + eol;

              }

         }

         // closing tag

         result       += "      " + tags.getClosingTagById(COLLECTION_DESCRIPTOR) + eol;

         return result;

     }

         /**

          * @return QueryCustomizer

          */

         public QueryCustomizer getQueryCustomizer()

         {

                 return m_queryCustomizer;

         }

         /**

          * Sets the queryCustomizer.

          * @param queryCustomizer The queryCustomizer to set

          */

         public void setQueryCustomizer(QueryCustomizer queryCustomizer)

         {

                 m_queryCustomizer = queryCustomizer;

         }

     public boolean hasProxyItems() throws PersistenceBrokerException

     {

         if (m_hasProxyItems == null)

         {

             DescriptorRepository repo = getClassDescriptor().getRepository();

             ClassDescriptor cld = repo.getDescriptorFor(getItemClass());

             if (cld.getProxyClass() != null)

             {

                 m_hasProxyItems = Boolean.TRUE;

             }

             else

             {

                 Collection extents = cld.getExtentClasses();

                 m_hasProxyItems = Boolean.FALSE;

                 for (Iterator it = extents.iterator(); it.hasNext(); )

                 {

                     Class ext = (Class) it.next();

                     ClassDescriptor cldExt = repo.getDescriptorFor(ext);

                     if (cldExt.getProxyClass() != null)

                     {

                         m_hasProxyItems = Boolean.TRUE;

                         break;

                     }

                 }

             }

         }

         return (m_hasProxyItems.booleanValue());

     }

 }