/* 
    * Copyright (c) 2012, Fraunhofer-Gesellschaft
    * All rights reserved.
    * 
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions are
    * met:
    * 
    * (1) Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the disclaimer at the end.
   *     Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in
   *     the documentation and/or other materials provided with the
   *     distribution.
   * 
   * (2) Neither the name of Fraunhofer nor the names of its
   *     contributors may be used to endorse or promote products derived
   *     from this software without specific prior written permission.
   * 
   * DISCLAIMER
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *  
   */
  package org.ogf.graap.wsag.wsrf;
  
  import java.text.MessageFormat;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Vector;
  
  import org.apache.log4j.Logger;
  import org.ogf.graap.wsag.server.engine.WsagEngine;
  import org.ogf.graap.wsag.server.persistence.IAgreementFactoryHome;
  import org.ogf.graap.wsag.server.persistence.PersistentAgreementFactory;
  
  /**
   * @author owaeld
   * 
   */
  public class WSAG4JPersistenceFacade
      implements IAgreementFactoryHome
  {
      private static final Logger LOG = Logger.getLogger( WSAG4JPersistenceFacade.class );
  
      private WsagEngine[] engines = new WsagEngine[0];
  
      /**
       * A map that contains the available persistent agreement factory which are identified by their factory
       * id.
       */
      protected Map<String, PersistentAgreementFactory> persistentFactories =
          new HashMap<String, PersistentAgreementFactory>();
  
      /**
       * An ordered list with the available agreement factories. The factories are stored in the order they were
       * retrieved from the persistence layer.
       */
      protected List<PersistentAgreementFactory> factoriesOL = new Vector<PersistentAgreementFactory>();
  
      /**
       * Creates a new facade for the given WSAG4J engines.
       * 
       * @param engines
       *            the available WSAG4J engines
       */
      public WSAG4JPersistenceFacade( WsagEngine[] engines )
      {
          this.engines = engines;
      }
  
      /**
       * @see IAgreementFactoryHome#initialize()
       */
      public void initialize()
      {
          persistentFactories.clear();
          factoriesOL.clear();
  
          for ( int i = 0; i < getEngines().length; i++ )
          {
              try
              {
                  IAgreementFactoryHome home = getEngines()[i].getPersistenceLayer();
                  PersistentAgreementFactory[] factories = home.list();
  
                  for ( int j = 0; j < factories.length; j++ )
                  {
                     if ( persistentFactories.containsKey( factories[j].getResourceId() ) )
                     {
                         String message1 =
                             "[duplicated resource id] "
                                 + "the agreement factory resource id must be unique in a WSAG4J engine.";
                         LOG.error( message1 );
 
                         String message2 =
                             "[duplicated resource id] the factory with resource id ''{0}'' was not loaded.";
                         LOG.error( MessageFormat.format( message2,
                             new Object[] { factories[j].getResourceId() } ) );
                     }
                     else
                     {
                         persistentFactories.put( factories[j].getResourceId(), factories[j] );
                         factoriesOL.add( factories[j] );
                     }
                 }
             }
             catch ( Exception e )
             {
                 LOG.error( "error loading persistence layer", e );
             }
         }
     }
 
     /**
      * looks up a factory with the given id.
      * 
      * @param factoryId
      *            the id of the factory to find
      * 
      * @return the factory
      * 
      * @throws Exception
      *             an error occurred while looking up the factory.
      * 
      * @see IAgreementFactoryHome#find(String)
      */
     public PersistentAgreementFactory find( String factoryId ) throws Exception
     {
         if ( persistentFactories.containsKey( factoryId ) )
         {
             return persistentFactories.get( factoryId );
         }
 
         return null;
     }
 
     /**
      * @return all available persistent factories
      * 
      * @throws Exception
      *             indicates an error while generating the factory list
      * 
      * @see org.ogf.graap.wsag.server.persistence.IAgreementFactoryHome#list()
      */
     public PersistentAgreementFactory[] list() throws Exception
     {
         return factoriesOL.toArray( new PersistentAgreementFactory[persistentFactories.size()] );
     }
 
     /**
      * @param factoryId
      *            removes the factory with the given id from the persistence layer
      * 
      * @throws Exception
      *             an error occurred while removing the factory
      * 
      * @see org.ogf.graap.wsag.server.persistence.IAgreementFactoryHome#remove(java.lang.String)
      */
     public void remove( String factoryId ) throws Exception
     {
         if ( persistentFactories.containsKey( factoryId ) )
         {
             factoriesOL.remove( persistentFactories.get( factoryId ) );
             persistentFactories.remove( factoryId );
         }
     }
 
     /**
      * Saves all factories.
      * 
      * @throws Exception
      *             indicates an error while saving the factories
      */
     public void save() throws Exception
     {
         PersistentAgreementFactory[] factories = list();
         for ( int i = 0; i < factories.length; i++ )
         {
             factories[i].save();
         }
     }
 
     /**
      * @param factories
      *            the factories to save
      * 
      * @throws Exception
      *             indicates an error while saving the factories
      * 
      * @see org.ogf.graap.wsag.server.persistence.IAgreementFactoryHome#saveAgreementFactories(org.ogf.graap.wsag.server.persistence.PersistentAgreementFactory[])
      */
     public void saveAgreementFactories( PersistentAgreementFactory[] factories ) throws Exception
     {
         for ( int i = 0; i < factories.length; i++ )
         {
             factories[i].save();
         }
     }
 
     /**
      * Returns the WSAG4J engine instances used by this facade.
      * 
      * @return the engine instances
      */
     public WsagEngine[] getEngines()
     {
         return engines;
     }
 }