/************************************************************************************
 * Copyright (C) 2008 by Politehnica University of Bucharest and Rutgers University
 * All rights reserved.
 * Refer to LICENSE for terms and conditions of use.
 ***********************************************************************************/
package vnsim.applications.vitp.peer;

import vnsim.applications.vitp.routing.*;
import vnsim.applications.vitp.services.*;
import vnsim.applications.vitp.ui.*;
import vnsim.applications.vitp.utils.*;

public class Peer {

	//a peer module, comunicating with a routing module (the layer below), 
	//a user interface (the layer above) and a services module, in order to 
	//properly serve VITP Requests

	public RoutingModule routingModule;
	private MessageProcessServices servicesModule;
	private UserInterface userInterfaceModule;

	public void attachModules(RoutingModule r, MessageProcessServices s, UserInterface ui){
		this.routingModule=r;
		this.servicesModule=s;
		this.userInterfaceModule=ui;
	}
	
	public boolean postMessageFromBelow(VITPMessage msg){
		//method to be called by the module below, in order to send a message
		//to this peer; returns true if the peer properly deals with the packet,
		//false otherwise

		//this peer has received a packet; there are several possibilities;

		//it could be a POST request or a reply; in that case, since it was 
		//delivered to me by the routing layer, it is for the local node, 
		//so it has to be delivered to the user interface

		//finally, it could be a GET request, in which case I have to try and satisfy
		//it, by using the services

		if(msg.isReply()) {
			return userInterfaceModule.postMessage(msg);
		}
		if(msg.isRequest()) {
			try{
				VITPRequest req=(VITPRequest)msg;
				if(req.isPost()) {
					//return userInterfaceModule.postMessage(msg);
					userInterfaceModule.postMessage(msg);
					return routingModule.postMessageFromAbove(msg);
				} else {
					if(req.isGet()){
						//use the services to try and satisfy this request
						VITPMessage mes=servicesModule.satisfy(req);
						return routingModule.postMessageFromAbove(mes);
					} else {
						System.out.println("ERROR! Unknown method:="+req.getMethod());
						return false;
					}
				}
			} catch (Exception ex){
				System.out.println("PEER_EXCEPTION:"+ex.toString());
				ex.printStackTrace();
				return false;
			}
		}
		System.out.println("Discarding! Peer.postMessage could not decide on the following message:"+msg);
		System.out.println("***");
		return false;
	}

	public boolean postMessageFromAbove(VITPMessage msg){
		//method to be called by the module above, in order to send a message
		//to this peer; returns true if the peer properly deals with the packet,
		//false otherwise
	
		//this peer has received a message from the user interface; it should be
		//a request
		if(msg.isRequest()) {
			msg.setMsgIdInval(); //invalidate the id; thus, the routing module will
							//see the invalid id, and provide it a new one
			return routingModule.postMessageFromAbove(msg);
		}
		return false;
	}
}