/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2009 The Georgia Institute of Technology 

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Authors: Josh Pelkey <jpelkey@gatech.edu>

 */

#ifndef __IPV4_NIX_VECTOR_ROUTING_H__

#define __IPV4_NIX_VECTOR_ROUTING_H__

#include <map>

#include "ns3/channel.h"

#include "ns3/node-container.h"

#include "ns3/node-list.h"

#include "ns3/net-device-container.h"

#include "ns3/ipv4-routing-protocol.h"

#include "ns3/ipv4-route.h"

#include "ns3/bridge-net-device.h"

namespace ns3 {

typedef std::map<Ipv4Address, Ptr<NixVector> > NixMap_t;

typedef std::map<Ipv4Address, Ptr<Ipv4Route> > Ipv4RouteMap_t;

class Ipv4NixVectorRouting : public Ipv4RoutingProtocol

{

  public:

    Ipv4NixVectorRouting ();

    ~Ipv4NixVectorRouting ();

    /** 

     * @brief The Interface ID of the Global Router interface. 

     * 

     * @see Object::GetObject () 

     */

    static TypeId GetTypeId (void); 

    /** 

     * @brief Set the Node pointer of the node for which this

     * routing protocol is to be placed

     *

     * @param node Node pointer 

     */

    void SetNode (Ptr<Node>);

    /** 

     * @brief Called when run-time link topology change occurs 

     * which iterates through the node list and flushes any 

     * nix vector caches

     * 

     */

    void FlushGlobalNixRoutingCache (void);

  private:

    /* flushes the cache which stores nix-vector based on

     * destination IP */

    void FlushNixCache (void);

    /* flushes the cache which stores the Ipv4 route 

     * based on the destination IP */

    void FlushIpv4RouteCache (void);

    /* upon a run-time topology change caches are 

     * flushed and the total number of neighbors is 

     * reset to zero */

    void ResetTotalNeighbors (void);

    /*  takes in the source node and dest IP and calls GetNodeByIp, 

     *  BFS, and BuildNixVector to finally return the built 

     *  nix-vector */

    Ptr<NixVector> GetNixVector (Ptr<Node>, Ipv4Address);

    /* checks the cache based on dest IP for the nix-vector */

    Ptr<NixVector> GetNixVectorInCache (Ipv4Address);

    /* checks the cache based on dest IP for the Ipv4Route */

    Ptr<Ipv4Route> GetIpv4RouteInCache (Ipv4Address);

    /* given a net-device returns all the adjacent net-devices, 

     * essentially getting the neighbors on that channel */

    void GetAdjacentNetDevices (Ptr<NetDevice>, Ptr<Channel>, NetDeviceContainer &);

    /* iterates through the node list and finds the one 

     * corresponding to the given Ipv4Address */

    Ptr<Node> GetNodeByIp (Ipv4Address);

    /* Recurses the parent vector, created by BFS and actually builds the nixvector */

    bool BuildNixVector (const std::vector< Ptr<Node> > & parentVector, uint32_t source, uint32_t dest, Ptr<NixVector> nixVector);

    /* special variation of BuildNixVector for when a node is sending to itself */

    bool BuildNixVectorLocal (Ptr<NixVector> nixVector);

    /* simple iterates through the nodes net-devices and determines 

     * how many neighbors it has */

    uint32_t FindTotalNeighbors (void);

    /* determine if the netdevice is bridged */

    Ptr<BridgeNetDevice> NetDeviceIsBridged (Ptr<NetDevice> nd) const;

    /* Nix index is with respect to the neighbors.  The net-device index must be 

     * derived from this */

    uint32_t FindNetDeviceForNixIndex (uint32_t nodeIndex, Ipv4Address & gatewayIp);

    /* Breadth first search algorithm

     * Param1: Vector containing all nodes in the graph

     * Param2: Source Node

     * Param3: Dest Node

     * Param4: (returned) Parent vector for retracing routes

     * Returns: false if dest not found, true o.w.

     */

    bool BFS (uint32_t numberOfNodes, 

             Ptr<Node> source, 

             Ptr<Node> dest, 

             std::vector< Ptr<Node> > & parentVector);

    void DoDispose (void);

    /* From Ipv4RoutingProtocol */

    virtual Ptr<Ipv4Route> RouteOutput (Ptr<Packet> p, const Ipv4Header &header, uint32_t oif, Socket::SocketErrno &sockerr);

    virtual bool RouteInput (Ptr<const Packet> p, const Ipv4Header &header, Ptr<const NetDevice> idev,

                             UnicastForwardCallback ucb, MulticastForwardCallback mcb,

                             LocalDeliverCallback lcb, ErrorCallback ecb);  

    virtual void NotifyInterfaceUp (uint32_t interface); 

    virtual void NotifyInterfaceDown (uint32_t interface); 

    virtual void NotifyAddAddress (uint32_t interface, Ipv4InterfaceAddress address); 

    virtual void NotifyRemoveAddress (uint32_t interface, Ipv4InterfaceAddress address); 

    virtual void SetIpv4 (Ptr<Ipv4> ipv4); 

    /* cache stores nix-vectors based on destination ip */

    NixMap_t m_nixCache;

    /* cache stores Ipv4Routes based on destination ip */

    Ipv4RouteMap_t m_ipv4RouteCache;

    Ptr<Ipv4> m_ipv4;

    Ptr<Node> m_node;

    /* total neighbors used for nix-vector to determine

     * number of bits */

    uint32_t m_totalNeighbors;

};

} // namepace ns3

#endif