/*******************************************************************************
 * Copyright 2013-2014 alladin-IT GmbH
 * 
 * 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 at.alladin.rmbt.qos.testserver.udp;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
import java.util.Set;
import java.util.TreeSet;
import java.util.concurrent.Callable;
import java.util.concurrent.atomic.AtomicBoolean;

import at.alladin.rmbt.qos.testserver.ServerPreferences.TestServerServiceEnum;
import at.alladin.rmbt.qos.testserver.TestServer;
import at.alladin.rmbt.qos.testserver.entity.ClientToken;
import at.alladin.rmbt.qos.testserver.util.TestServerConsole;

/**
 * 
 * @author lb
 *
 */
public class UdpSingleClientServer implements Callable<Integer> {
	
	private final AtomicBoolean isRunning;
	
	public final static int BUFFER_LENGTH = 1024;

	final DatagramSocket socket;
	
	final ClientToken token;
	
	final int numPackets;
	
	private int receivedPackets = 0;
	
	/********************************************
	 * UDP PACKET DATA
	 ********************************************/
	
	public final static byte UDP_IN_TEST_IDENTIFIER = 1;
	 

	/**
	 * 
	 * @param port
	 * @param timeOut
	 * @throws SocketException
	 */
	public UdpSingleClientServer(int port, int numPackets, int timeOut, ClientToken token) throws SocketException {
		TestServerConsole.log("Initializing UdpServer on port: " + port, 0, TestServerServiceEnum.UDP_SERVICE);
		this.socket = new DatagramSocket(port);
		this.socket.setSoTimeout(timeOut);
		this.isRunning = new AtomicBoolean(false);
		this.token = token;
		this.numPackets = numPackets;
	}

	/**
	 * 
	 * @param socket
	 * @param timeOut
	 * @param token
	 * @throws SocketException
	 */
	public UdpSingleClientServer(DatagramSocket socket, int timeOut, ClientToken token) throws SocketException {
		TestServerConsole.log("Starting UdpSingleClientServer on port: " + socket.getLocalPort(), 0, TestServerServiceEnum.UDP_SERVICE);
		this.socket = socket;
		this.socket.setSoTimeout(timeOut);
		this.isRunning = new AtomicBoolean(false);
		this.token = token;
		this.numPackets = 0;
	}

	/*
	 * (non-Javadoc)
	 * @see java.lang.Runnable#run()
	 */
	@Override
	public Integer call() {
		isRunning.set(true);

		Set<Integer> packetReceived = new TreeSet<>();
		
		try {
			while (isRunning.get()) {
				byte[] buffer = new byte[BUFFER_LENGTH];
				DatagramPacket dp = new DatagramPacket(buffer, BUFFER_LENGTH);
				
				socket.receive(dp);
				receivedPackets++;
				byte[] data = dp.getData();
				
				//check udp packet:
				if (data[0] != UDP_IN_TEST_IDENTIFIER) {
					throw new IOException("bad UDP IN TEST identifier");
				}

				//check for duplicate packets:
				int packetNumber = data[1];
				if (packetReceived.contains(packetNumber)) {
					throw new IOException("duplicate UDP IN TEST packet");
				}
				
				
				char[] uuid = new char[dp.getLength() - 2];
				for (int i = 2; i < dp.getLength(); i++) {
					uuid[i-2] = (char) data[i];
				}
				
				if (TestServer.serverPreferences.getVerboseLevel() >= 1) {
					TestServerConsole.log("received UDP from: " + dp.getAddress().toString() + ", #" + packetNumber + ", uuid: " + String.valueOf(uuid), 1, TestServerServiceEnum.UDP_SERVICE);
				}

				//received enough packets? exit loop
				if (receivedPackets >= numPackets) {
					break;
				}
			}		
		} 
		catch (Exception e) {
			e.printStackTrace();
		}
		finally {
			if (!socket.isClosed()) {
				socket.close();
			}
		}
		
		TestServerConsole.log("UdpServer shutdown on port: " + socket.getPort(), 0, TestServerServiceEnum.UDP_SERVICE);
		return new Integer(receivedPackets);
	}

	/**
	 * 
	 * @return
	 */
	public boolean getIsRunning() {
		return isRunning.get();
	}
	
	/**
	 * 
	 * @return
	 */
	public int getReceivedPacketsCount() {
		return receivedPackets;
	}

	/**
	 * 
	 */
	public void quit() {
		isRunning.set(false);
		TestServerConsole.log("UdpServer received quit command on port: " + socket.getPort(), 0, TestServerServiceEnum.UDP_SERVICE);
	}
}