/* -*-  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> 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, accounting for any output interface specified, and finally 
     *  BuildNixVector to return the built nix-vector */
    Ptr<NixVector> GetNixVector (Ptr<Node>, Ipv4Address, Ptr<NetDevice>);

    /* 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: total number of nodes
     * Param2: Source Node
     * Param3: Dest Node
     * Param4: (returned) Parent vector for retracing routes
     * Param5: specific output interface to use from source node, if not null
     * 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,
             Ptr<NetDevice> oif);

    void DoDispose (void);

    /* From Ipv4RoutingProtocol */
    virtual Ptr<Ipv4Route> RouteOutput (Ptr<Packet> p, const Ipv4Header &header, Ptr<NetDevice> 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
