/**
 * routestrategy.h
 * Implemented by Blueprint Technologies, Inc.
 * This file defines startegy classes to determine
 * how packet routing through a network will be handled.
 */

#ifndef _routestrategy_h
#define _routestrategy_h

/**
 * Include the data types with which the strategy works.
 */

#include "routetypes.h"

/**
 * This class declares an interface common to all
 * classes involved in determining how to route packets
 * through a complex network.
 */

class RouteStrategy
{

public:

	/**
	 * This may not be entirely true-to-life. Based on where
	 * the packet is now, determine the next node to send the packet
	 * to get that packet to its target address. This method takes
	 * a target network address and returns the next network
	 * address the packet should go to.
	 */

	virtual NetworkAddress& getNextHop( NetworkAddress& TargetAddress ) = 0;

};

/**
 * This implementation of the RouteStrategy class determines
 * how to send a data packet through a set of networks based 
 * on a least cost approach.
 */

class MinimalCostRouteStrategy: public RouteStrategy
{

public:
	virtual NetworkAddress& getNextHop( NetworkAddress& TargetAddress )
	{
		NetworkAddress nextAddress;
		return nextAddress;
	};
};

/**
 * This implementation of the RouteStrategy class determines
 * how to send a data packet through a set of networks based 
 * on a least amount of time to target approach.
 */

class MinimalTimeRouteStrategy: public RouteStrategy
{

public:
	virtual NetworkAddress& getNextHop( NetworkAddress& TargetAddress )
	{
		NetworkAddress nextAddress;
		return nextAddress;
	};
};

/**
 * This class is the contextual interface for the client to
 * determine how to route a packet through a network.
 */

class Router
{

private:

	/**
	 * This is the strategy which is stored as an abstract
	 * pointer to a concrete RouteStrategy object.
	 */

	RouteStrategy* strategy;

public:

	/**
	 * Default constructor.
	 */

	Router()
	{
		strategy = (RouteStrategy *) 0;
	};

public:

	/**
	 * This method defines the main interface a client
	 * will use to find a route for a data packet.
	 */

	void routePacket( DataPacket& packet, NetworkAddress& targetAddress )
	{
		NetworkAddress nextAddress;
		nextAddress = strategy -> getNextHop( targetAddress );

		/**
		 * Send the packet to that address.
		 */
	};

public:

	/**
	 * These method represent the accessors used for
	 * changing the route strategy during run-time.
	 */

	RouteStrategy* getStrategy()
	{
		return strategy;
	};

	void setStrategy( RouteStrategy* newStrategy)
	{
		strategy = newStrategy;
	};
};

#endif