/*
 * Copyright 2000-2004 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.
 */

package org.apache.jetspeed.om.registry.base;

import org.apache.jetspeed.om.registry.MediaTypeRegistry;
import org.apache.jetspeed.om.registry.MediaTypeEntry;
import org.apache.jetspeed.om.registry.RegistryEntry;
import org.apache.jetspeed.om.registry.InvalidEntryException;
import org.apache.jetspeed.om.registry.RegistryException;
import org.apache.jetspeed.services.Registry;
import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
import org.apache.jetspeed.services.logging.JetspeedLogger;
import org.apache.jetspeed.capability.CapabilityMap;

import java.util.Iterator;
import java.util.Enumeration;
import java.util.List;
import java.util.ArrayList;

/**
 * Extends BaseRegistry implementation to override object creation
 * method
 *
 * @author <a href="mailto:raphael@apache.org">Rapha�l Luta</a>
 * @version $Id: BaseMediaTypeRegistry.java,v 1.7 2004/02/23 03:08:26 jford Exp $
 */
public class BaseMediaTypeRegistry extends BaseOrderedRegistry
        implements MediaTypeRegistry
{

    /**
     * Static initialization of the logger for this class
     */    
    private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(BaseMediaTypeRegistry.class.getName());    
    
    /*
     * Find media-types in this registry that match the CapabilityMap requirements
     *
     * @param category The category and optional subcategories.
     * @return Iterator The result as an iterator.
     */
    public Iterator findForCapability(CapabilityMap cm)
    {
        if (cm == null)
        {
            return null;
        }

        String type = cm.getPreferredType().getContentType();
        List result = new ArrayList();

        if ( logger.isDebugEnabled() )
        {
            logger.debug("MediaTypeRegistry: looking for type " + type );
        }

        if (type == null)
        {
            return result.iterator();
        }

        try
        {
            Enumeration en = getEntries();
            while(en.hasMoreElements())
            {
                MediaTypeEntry mte = (MediaTypeEntry)en.nextElement();

                if ( logger.isDebugEnabled() )
                {
                    logger.debug("MediaTypeRegistry: found MediaTypeEntry for type " + mte.getMimeType() );
                }
                if (type.equals(mte.getMimeType()))
                {
                    result.add(mte);
                }
            }
        }
        catch(Exception e)
        {
            logger.error("Exception", e);
        }

        if ( logger.isDebugEnabled() )
        {
            logger.debug("MediaTypeRegistry: found " + result.size() + " entries." );
        }

        return result.iterator();

    }

    /**
    @see Registry#setEntry
    */
    public void setEntry( RegistryEntry entry ) throws InvalidEntryException
    {
        // Delegate to the RegistryService to ensure correct handling of
        // persistence if using file fragments

        try
        {
            Registry.addEntry(Registry.MEDIA_TYPE, entry);
        }
        catch (RegistryException e)
        {
            logger.error("Exception", e);
        }
    }

    /**
    @see Registry#addEntry
    */
    public void addEntry( RegistryEntry entry ) throws InvalidEntryException
    {
        // Delegate to the RegistryService to ensure correct handling of
        // persistence if using file fragments

        try
        {
            Registry.addEntry(Registry.MEDIA_TYPE, entry);
        }
        catch (RegistryException e)
        {
            logger.error("Exception", e);
        }
    }

    /**
    @see Registry#removeEntry
    */
    public void removeEntry( String name )
    {
        // Delegate to the RegistryService to ensure correct handling of
        // persistence if using file fragments

        Registry.removeEntry(Registry.MEDIA_TYPE, name);
    }

    /**
    @see Registry#removeEntry
    */
    public void removeEntry( RegistryEntry entry )
    {
        // Delegate to the RegistryService to ensure correct handling of
        // persistence if using file fragments

        if (entry != null)
        {
            Registry.removeEntry(Registry.MEDIA_TYPE, entry.getName());
        }
    }

    /**
     * Creates a new RegistryEntry instance compatible with the current
     * Registry instance implementation
     *
     * @return the newly created RegistryEntry
     */
    public RegistryEntry createEntry()
    {
        return new BaseMediaTypeEntry();
    }
}