/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.qpid.server.virtualhost;

import org.apache.qpid.common.Closeable;
import org.apache.qpid.server.exchange.ExchangeRegistry;
import org.apache.qpid.server.registry.ApplicationRegistry;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;


public class VirtualHostRegistry implements Closeable
{
    private final Map<String, VirtualHost> _registry = new ConcurrentHashMap<String, VirtualHost>();


    private String _defaultVirtualHostName;
    private ApplicationRegistry _applicationRegistry;
    private final Collection<RegistryChangeListener> _listeners =
            Collections.synchronizedCollection(new ArrayList<RegistryChangeListener>());

    public VirtualHostRegistry(ApplicationRegistry applicationRegistry)
    {
        _applicationRegistry = applicationRegistry;
    }

    public synchronized void registerVirtualHost(VirtualHost host) throws Exception
    {
        if(_registry.containsKey(host.getName()))
        {
            throw new Exception("Virtual Host with name " + host.getName() + " already registered.");
        }
        _registry.put(host.getName(),host);
        synchronized (_listeners)
        {
            for(RegistryChangeListener listener : _listeners)
            {
                listener.virtualHostRegistered(host);
            }
        }
    }
    
    public synchronized void unregisterVirtualHost(VirtualHost host)
    {
        _registry.remove(host.getName());
        synchronized (_listeners)
        {
            for(RegistryChangeListener listener : _listeners)
            {
                listener.virtualHostUnregistered(host);
            }
        }
    }

    public VirtualHost getVirtualHost(String name)
    {
        if(name == null || name.trim().length() == 0 || "/".equals(name.trim()))
        {
            name = getDefaultVirtualHostName();
        }

        return _registry.get(name);
    }

    public VirtualHost getDefaultVirtualHost()
    {
        return getVirtualHost(getDefaultVirtualHostName());
    }

    private String getDefaultVirtualHostName()
    {
        return _defaultVirtualHostName;
    }

    public void setDefaultVirtualHostName(String defaultVirtualHostName)
    {
        _defaultVirtualHostName = defaultVirtualHostName;
    }


    public Collection<VirtualHost> getVirtualHosts()
    {
        return new ArrayList<VirtualHost>(_registry.values());
    }

    public ApplicationRegistry getApplicationRegistry()
    {
        return _applicationRegistry;
    }

    public void close()
    {
        for (VirtualHost virtualHost : getVirtualHosts())
        {
            virtualHost.close();
        }

    }

    public static interface RegistryChangeListener
    {
        void virtualHostRegistered(VirtualHost virtualHost);
        void virtualHostUnregistered(VirtualHost virtualHost);

    }

    public void addRegistryChangeListener(RegistryChangeListener listener)
    {
        _listeners.add(listener);
    }

}
