/*
 * Copyright 2000-2001,2004 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.RegistryEntry;
import org.apache.jetspeed.om.registry.InvalidEntryException;
import java.util.Map;
import java.util.TreeMap;
import java.util.Iterator;
import java.util.Enumeration;
import java.util.Vector;

/**
 * Provides base functionality within a Registry.
 *
 * @author <a href="mailto:burton@apache.org">Kevin A. Burton</a>
 * @author <a href="mailto:raphael@apache.org">Rapha雔 Luta</a>
 * @version $Id: BaseRegistry.java,v 1.7 2004/02/23 03:08:26 jford Exp $
 */
public class BaseRegistry implements LocalRegistry
{
    protected static final boolean DEBUG = false;

    protected Map entries = new TreeMap();

    /** @see Registry#getEntryCount */
    public int getEntryCount()
    {
        return this.entries.size();
    }

    /** @see Registry#getEntry */
    public RegistryEntry getEntry( String name ) throws InvalidEntryException
    {

        RegistryEntry entry = null;

        if (name != null)
        {
            entry = (RegistryEntry)this.entries.get( name ) ;
        }

        if (entry == null)
        {
            throw new InvalidEntryException( InvalidEntryException.ENTRY_DOES_NOT_EXIST+" "+name );
        }

        return entry;
    }

    /**
    @see Registry#setEntry
    */
    public void setEntry( RegistryEntry entry ) throws InvalidEntryException
    {
        synchronized (this)
        {

            if ( this.hasEntry( entry.getName() ) == false )
            {
                throw new InvalidEntryException( InvalidEntryException.ENTRY_DOES_NOT_EXIST+" "+entry.getName());
            }

            this.entries.put( entry.getName(), entry );
        }
    }

    /**
    @see Registry#addEntry
    */
    public void addEntry( RegistryEntry entry ) throws InvalidEntryException
    {

        synchronized (this)
        {
            if ( this.hasEntry( entry.getName() ) )
            {
                throw new InvalidEntryException( InvalidEntryException.ENTRY_ALREADY_PRESENT );
            }

            this.entries.put( entry.getName(), entry );
        }
    }

    /**
       @see Registry#hasEntry
    */
    public boolean hasEntry( String name )
    {
        return this.entries.containsKey( name );
    }

    /**
    @see Registry#removeEntry
    */
    public void removeEntry( String name )
    {
        synchronized(this)
        {
            this.entries.remove( name );
        }
    }

    /**
    @see Registry#removeEntry
    */

    public void removeEntry( RegistryEntry entry )
    {
        synchronized(this)
        {
            this.entries.remove( entry.getName() );
        }
    }

    /**
       @see Registry#getEntries
     */
    public Enumeration getEntries()
    {
        Vector v = null;

        synchronized (this)
        {
            // this is ne
            v = new Vector(this.entries.values());
        }

        return v.elements();
    }

    /**
       @see Registry#listEntryNames
     */
    public Iterator listEntryNames()
    {
        return entries.keySet().iterator();
    }

    /**
       @see Registry#toArray
     */
    public RegistryEntry[] toArray()
    {

        Enumeration enum = getEntries();
        Vector v = new Vector();

        while( enum.hasMoreElements() )
        {
            v.addElement( enum.nextElement() );
        }

        RegistryEntry[] entries = new RegistryEntry[ v.size() ];
        v.copyInto( entries );
        return entries;

    }

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


    // RegistryService specific methods

    /**
     * This method is used  to only set the entry in the local
     * memory cache of the registry without any coherency check with
     * persistent storage
     *
     * @param entry the RegistryEntry to store
     */
    public void setLocalEntry( RegistryEntry entry ) throws InvalidEntryException
    {
        synchronized (this)
        {

            if ( this.hasEntry( entry.getName() ) == false )
            {
                throw new InvalidEntryException( InvalidEntryException.ENTRY_DOES_NOT_EXIST+" "+entry.getName());
            }

            this.entries.put( entry.getName(), entry );
        }
    }

    /**
     * This method is used to only add the entry in the local
     * memory cache of the registry without any coherency check with
     * persistent storage
     *
     * @param entry the RegistryEntry to store
     */
    public void addLocalEntry( RegistryEntry entry ) throws InvalidEntryException
    {

        synchronized (this)
        {
            if ( this.hasEntry( entry.getName() ) )
            {
                throw new InvalidEntryException( InvalidEntryException.ENTRY_ALREADY_PRESENT );
            }

            this.entries.put( entry.getName(), entry );
        }
    }

    /**
     * This method is used to only remove the entry from the local
     * memory cache of the registry without any coherency check with
     * persistent storage
     *
     * @param name the name of the RegistryEntry to remove
     */
    public void removeLocalEntry( String name )
    {
        synchronized(this)
        {
            this.entries.remove( name );
        }
    }

    /**
     * This method is used to only remove the entry from the local
     * memory cache of the registry without any coherency check with
     * persistent storage
     *
     * @param entry the RegistryEntry to remove
     */
    public void removeLocalEntry( RegistryEntry entry )
    {
        synchronized(this)
        {
            this.entries.remove( entry.getName() );
        }
    }

}