/*
 * Author: Wenbing Zhao
 * Last Modified: 3/31/2007
 * For EEC484/584 Project 
 */

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

public class Alice {
    private DatagramSocket m_socket = null;
    private Node m_bob = null;
    private Node m_alice = null;

    public Alice() {
	LinkStateConfig config = LinkStateConfig.getInstance();
	m_alice = config.getAliceRouter();
	m_bob = config.getBobRouter();
	int myport = config.getAlicePort();

	try {
	    m_socket = new DatagramSocket(myport); 
	} catch(Exception e) {
	    System.out.println("Error creating socket: "+e);
	}	   
    }

    public void run() {
	Random gen = new Random();
	Packet p = new Packet();
	p.dest = m_bob.getName();
	p.src = m_alice.getName();
	p.seq = gen.nextInt(1000);

	String msg = "Hello World";
	p.length = msg.length();
	p.payload = "Hello World".getBytes();
	
	// Note that we are sending the packet to the router
	// that Alice is attached to, not the one that Bob is
	// attached to. We certainly could send to Bob's router,
	// but we will lose the opportunity to exercise routing!
	sendToNode(m_alice, p);
	System.out.println("Sent to Bob: "+msg);
    }

    private void sendToNode(Node n, Packet packet) {
	InetAddress ip = n.getIPAddress();
	int port = n.getPort();
	byte[] payload = packet.toBytes();

	try {
	    DatagramPacket p = 
		new DatagramPacket(payload, payload.length, ip, port);
	    m_socket.send(p);
	} catch(Exception e) {
	    System.out.println("Error sending packet: "+e);
	}	   
    }

    public static void main(String argsp[]) throws Exception {
	Alice alice = new Alice();
	alice.run();
    }
}