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

/*

 * Copyright (c) 2009 IITP RAS

 *

 * 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

 *

 * Based on

 *      NS-2 AODV model developed by the CMU/MONARCH group and optimized and

 *      tuned by Samir Das and Mahesh Marina, University of Cincinnati;

 *

 *      AODV-UU implementation by Erik Nordström of Uppsala University

 *      http://core.it.uu.se/core/index.php/AODV-UU

 *

 * Authors: Elena Buchatskaia <borovkovaes@iitp.ru>

 *          Pavel Boyko <boyko@iitp.ru>

 */

#include "aodv-neighbor.h"

#include "ns3/log.h"

#include <algorithm>

NS_LOG_COMPONENT_DEFINE ("AodvNeighbors");

namespace ns3

{

namespace aodv

{

Neighbors::Neighbors (Time delay) : 

  m_ntimer (Timer::CANCEL_ON_DESTROY)

{

  m_ntimer.SetDelay(delay);

  m_ntimer.SetFunction(&Neighbors::Purge, this);

  m_txErrorCallback = MakeCallback (& Neighbors::ProcessTxError, this);

}

bool

Neighbors::IsNeighbor (Ipv4Address addr)

{

  Purge ();

  for (std::vector<Neighbor>::const_iterator i = m_nb.begin ();

      i != m_nb.end (); ++i)

    {

      if (i->m_neighborAddress == addr)

        return true;

    }

  return false;

}

Time

Neighbors::GetExpireTime (Ipv4Address addr)

{

  Purge ();

  for (std::vector<Neighbor>::const_iterator i = m_nb.begin (); i

      != m_nb.end (); ++i)

    {

      if (i->m_neighborAddress == addr)

        return (i->m_expireTime - Simulator::Now ());

    }

  return Seconds (0);

}

void

Neighbors::Update (Ipv4Address addr, Time expire)

{

  for (std::vector<Neighbor>::iterator i = m_nb.begin (); i != m_nb.end (); ++i)

    if (i->m_neighborAddress == addr)

      {

        i->m_expireTime

            = std::max (expire + Simulator::Now (), i->m_expireTime);

        if (i->m_hardwareAddress == Mac48Address ())

          i->m_hardwareAddress = LookupMacAddress (i->m_neighborAddress);

        return;

      }

  NS_LOG_LOGIC ("Open link to " << addr);

  Neighbor neighbor (addr, LookupMacAddress (addr), expire + Simulator::Now ());

  m_nb.push_back (neighbor);

  Purge ();

}

struct CloseNeighbor

{

  bool operator() (const Neighbors::Neighbor & nb) const

  {

    return ((nb.m_expireTime < Simulator::Now ()) || nb.close);

  }

};

void

Neighbors::Purge ()

{

  if (m_nb.empty ())

    return;

  CloseNeighbor pred;

  if (!m_handleLinkFailure.IsNull ())

    {

      for (std::vector<Neighbor>::iterator j = m_nb.begin (); j != m_nb.end (); ++j)

        {

          if (pred (*j))

            {

              NS_LOG_LOGIC ("Close link to " << j->m_neighborAddress);

              m_handleLinkFailure (j->m_neighborAddress);

            }

        }

    }

  m_nb.erase (std::remove_if (m_nb.begin (), m_nb.end (), pred), m_nb.end ());

  m_ntimer.Cancel ();

  m_ntimer.Schedule ();

}

void

Neighbors::ScheduleTimer ()

{

  m_ntimer.Cancel ();

  m_ntimer.Schedule ();

}

void

Neighbors::AddArpCache (Ptr<ArpCache> a)

{

  m_arp.push_back (a);

}

void

Neighbors::DelArpCache (Ptr<ArpCache> a)

{

  m_arp.erase (std::remove (m_arp.begin (), m_arp.end (), a), m_arp.end ());

}

Mac48Address

Neighbors::LookupMacAddress (Ipv4Address addr)

{

  Mac48Address hwaddr;

  for (std::vector<Ptr<ArpCache> >::const_iterator i = m_arp.begin ();

      i != m_arp.end (); ++i)

    {

      ArpCache::Entry * entry = (*i)->Lookup (addr);

      if (entry != 0 && entry->IsAlive () && !entry->IsExpired ())

        {

          hwaddr = Mac48Address::ConvertFrom (entry->GetMacAddress ());

          break;

        }

    }

  return hwaddr;

}

void

Neighbors::ProcessTxError (WifiMacHeader const & hdr)

{

  Mac48Address addr = hdr.GetAddr1 ();

  for (std::vector<Neighbor>::iterator i = m_nb.begin (); i != m_nb.end (); ++i)

    {

      if (i->m_hardwareAddress == addr)

        i->close = true;

    }

  Purge ();

}

}

}