package NClientServer;

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

/**
 * @author Ricardo Gaspar, N�35277
 *
 */

public class MyConcurrentServer {
	
	public static void main(String[] args) throws Exception {
		
		//Conjunto dos Clientes que comunicam com o servidor
		Set<InetSocketAddress> clients = new HashSet<InetSocketAddress>();
		Iterator<InetSocketAddress> clientsIterator;
		
		if( args.length != 1 ) {
			System.out.printf("usage: java MyServer porto\n") ;
			System.exit(0);
		}
		
		int port =  Integer.parseInt(args[0]);
		
		System.out.println("Servidor iniciado!");
		
		// inicializar o socket com o porto de atendimento
		DatagramSocket socket = new DatagramSocket( port ) ;
		
		for(;;) { //ciclo infinito de atendimento...

			//preparar uma mensagem (datagrama) vazia para recepcao...
			byte[] buffer = new byte[65536] ;
			DatagramPacket echoRequest = new DatagramPacket( buffer, buffer.length ) ;
		
			//receber a mensagem...
			socket.receive( echoRequest ) ;
			
			//obter o conteudo da mensagem recebida...
			byte[] echoRequestData = echoRequest.getData();
			int echoRequestLength = echoRequest.getLength() ;
			//obter o endere�o IP e o porto do cliente 
			InetSocketAddress clientID = new InetSocketAddress(echoRequest.getAddress(), echoRequest.getPort()) ;
			
			//Adiciona ao conjunto de clientes conhecidos
			clients.add(clientID);
			
			String message = new String( echoRequestData, 0, echoRequestLength);
			
			System.out.println(message);			
			
			clientsIterator = clients.iterator();
			
			//Para cada cliente que o servidor conhe�a, reencaminha a mensagem enviada
			while(clientsIterator.hasNext()){
				
				InetSocketAddress c = clientsIterator.next();
				DatagramPacket echoReply = new DatagramPacket(message.getBytes(), 0, message.getBytes().length, c.getAddress(), c.getPort());
				
				socket.send(echoReply);
			}
			
			
		}
	}
	
}