/*
 * Copyright 2011 The Netty Project
 *
 * The Netty Project 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.jboss.netty.example.qotm;

import java.net.InetSocketAddress;
import java.util.concurrent.Executors;

import org.jboss.netty.bootstrap.ConnectionlessBootstrap;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.FixedReceiveBufferSizePredictorFactory;
import org.jboss.netty.channel.socket.DatagramChannel;
import org.jboss.netty.channel.socket.DatagramChannelFactory;
import org.jboss.netty.channel.socket.nio.NioDatagramChannelFactory;
import org.jboss.netty.handler.codec.string.StringDecoder;
import org.jboss.netty.handler.codec.string.StringEncoder;
import org.jboss.netty.util.CharsetUtil;

/**
 * A UDP broadcast client that asks for a quote of the moment (QOTM) to
 * {@link QuoteOfTheMomentServer}.
 *
 * Inspired by <a href="http://java.sun.com/docs/books/tutorial/networking/datagrams/clientServer.html">the official Java tutorial</a>.
 */
public class QuoteOfTheMomentClient {

    private final int port;

    public QuoteOfTheMomentClient(int port) {
        this.port = port;
    }

    public void run() {
        DatagramChannelFactory f =
            new NioDatagramChannelFactory(Executors.newCachedThreadPool());

        ConnectionlessBootstrap b = new ConnectionlessBootstrap(f);

        // Configure the pipeline factory.
        b.setPipelineFactory(new ChannelPipelineFactory() {
            public ChannelPipeline getPipeline() throws Exception {
                return Channels.pipeline(
                        new StringEncoder(CharsetUtil.ISO_8859_1),
                        new StringDecoder(CharsetUtil.ISO_8859_1),
                        new QuoteOfTheMomentClientHandler());
            }
        });

        // Enable broadcast
        b.setOption("broadcast", "true");

        // Allow packets as large as up to 1024 bytes (default is 768).
        // You could increase or decrease this value to avoid truncated packets
        // or to improve memory footprint respectively.
        //
        // Please also note that a large UDP packet might be truncated or
        // dropped by your router no matter how you configured this option.
        // In UDP, a packet is truncated or dropped if it is larger than a
        // certain size, depending on router configuration.  IPv4 routers
        // truncate and IPv6 routers drop a large packet.  That's why it is
        // safe to send small packets in UDP.
        b.setOption(
                "receiveBufferSizePredictorFactory",
                new FixedReceiveBufferSizePredictorFactory(1024));

        DatagramChannel c = (DatagramChannel) b.bind(new InetSocketAddress(0));

        // Broadcast the QOTM request to port 8080.
        c.write("QOTM?", new InetSocketAddress("255.255.255.255", port));

        // QuoteOfTheMomentClientHandler will close the DatagramChannel when a
        // response is received.  If the channel is not closed within 5 seconds,
        // print an error message and quit.
        if (!c.getCloseFuture().awaitUninterruptibly(5000)) {
            System.err.println("QOTM request timed out.");
            c.close().awaitUninterruptibly();
        }

        f.releaseExternalResources();
    }

    public static void main(String[] args) throws Exception {
        int port;
        if (args.length > 0) {
            port = Integer.parseInt(args[0]);
        } else {
            port = 8080;
        }
        new QuoteOfTheMomentClient(port).run();
    }
}