package jahspotify.client;

/*
 * 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.
 */

import java.net.*;
import java.util.*;

import com.google.gson.Gson;
import jahspotify.web.system.ServerIdentity;

/**
 * @author Johan Lindquist
 */
public class ServerBroadcasterClient
{

    public static void main(String[] args) throws Exception
    {
        final Set<ServerIdentity> serverIdentities = ServerBroadcasterClient.discoverServers("224.0.0.1", 9764, 10000, new ServerFoundListener()
        {

            @Override
            public void serverFound(final ServerIdentity serverIdentity)
            {
                System.out.println("serverIdentity = " + serverIdentity);
            }
        });



    }

    public static Set<ServerIdentity> discoverServers(String address, int port, int timeout, final ServerFoundListener serverFoundListener) throws Exception
    {
        Set<ServerIdentity> serversFound = new HashSet<ServerIdentity>();
        InetAddress group = InetAddress.getByName(address);
        MulticastSocket multicastSocket = new MulticastSocket(port);
        multicastSocket.joinGroup(group);

        long s1 = System.currentTimeMillis();
        while (s1 + timeout > System.currentTimeMillis())
        {
            // get their responses!
            byte[] buf = new byte[1000];
            DatagramPacket recv = new DatagramPacket(buf, buf.length);
            multicastSocket.receive(recv);
            String message = new String(recv.getData(), recv.getOffset(), recv.getLength());
            Gson gson = new Gson();
            final ServerIdentity serverIdentity = gson.fromJson(message, ServerIdentity.class);
            if (serverIdentity.getServerWebAddress() == null)
            {
                serverIdentity.setServerWebAddress(recv.getAddress().getHostAddress());
            }
            if (serversFound.add(serverIdentity) && serverFoundListener != null)
            {
                serverFoundListener.serverFound(serverIdentity);
            }
            serversFound.add(serverIdentity);
        }


        // OK, I'm done talking - leave the group...
        multicastSocket.leaveGroup(group);

        return serversFound;

    }

    public static interface ServerFoundListener
    {
        public void serverFound(ServerIdentity serverIdentity);
    }
}