package com.theorem.radserver3.examples.server;

import com.theorem.radserver3.*;
import com.theorem.radserver3.radutil.*;
import com.theorem.misc.*;
import java.util.*;

/**
* Sends packets to a series of servers in an attempt to load balance
* server usage or handle dead or busy servers.
*/
public class ProxyFailover extends ProxyImpl
{
	LogImpl dbg, svr;
	Configure conf;

	// Timer for creating a list of servers to try.
	Timer timer;

	// Circular list of servers to try.
	CircularList serverList = new CircularList();

	// List of timer object.  They will remove themselves as they expire.
	// This is required so a Timer won't disappear because of a lack of a reference.
	ArrayList timerList = new ArrayList();

	/**
	* Constructor.
	* @param conf Configuration object.
	*/
	public ProxyFailover(Configure conf)
	{
		super();
		this.conf = conf;
		timer = new Timer();

// For the sake of testing add the same server twice.
addServer("andromeda");
addServer("andromeda");
	}

	/**
	* Intialize the logs for this class.
	*
	* @param svrLog Server log object.
	* @param dbgLog Debug log object.
	*/
	public void logs(LogImpl svrLog, LogImpl dbgLog)
	{
		dbg = dbgLog;
		svr = svrLog;
	}

	/**
	* Method to add a server to the circular list.
	* @param server Server realm.
	* The realm must be in our list of proxy target servers.
	*/
	public void addServer(String server)
	{
		serverList.add(server);
	}

	/**
	* Send a proxy request to a number of servers in the hopes one will respond.
	*
	* @param prx ProxyInfo object from server.
	*/
	public void changeRequest(ProxyInfo prx) throws AccessDropException, AccessRejectException
	{
		timer = new Timer();
		timerList.add(timer);

		try {
			// Try sending a packet from within this method.
			// Set up the proxyClient with no particular associated object.
			ProxyClient pc = prx.getProxyClient(false, PacketType.Access_Request, prx.getRequestAttributeList(), null);

			// Create the packet timeout object that will handle all the attempts
			// to send the packet.
			ProxyPacketTimeout t = new ProxyPacketTimeout(timer, pc, timerList);

			// Add realms from the circular list - start with a random entry.
			Random r = new Random();
			int count = serverList.size();
			int skip =  r.nextInt() % count;
			for (int i = 0; i < count; i++)
				serverList.next();

			for (int i = 0; i < count; i++)
				t.addRealm((String) serverList.next());

			// Set the time between attempts to some number of seconds.
			t.setInterval(2);

			// Set the timer.
			t.go();

		} catch (RADIUSServerException rse) {
			System.out.println(rse.getMessage());
		} catch (AccessDropException ade) {
			System.out.println(ade.getMessage());
		}

		// Unless we make this more sophisticated drop the original packet so we don't
		// send it to one of the proxy servers twice.
		throw new AccessDropException("Dropping original packet");
	}

	/**
	* Change proxy response routing.
	* Don't actually change a proxies response attributes in this case.
	*
	* @param prx ProxyInfo object from server.
	*/
	public void changeResponse(ProxyInfo prx)  throws AccessDropException, AccessRejectException
	{
		// Once a packet is successfully recovered cancel the timer.
		ProxyPacketTimeout ppt = (ProxyPacketTimeout) prx.getProxyStateObject();
		if (ppt != null)
		{
			System.out.println("Time left on the timer is " + (new Date().getTime() - ppt.scheduledExecutionTime()));
			ppt.cancel();
		}
	}
}