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

/*

 * Copyright (c) 2011 Yufei Cheng

 *

 * 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

 *

 * Author: Yufei Cheng   <yfcheng@ittc.ku.edu>

 *

 * James P.G. Sterbenz <jpgs@ittc.ku.edu>, director

 * ResiliNets Research Group  http://wiki.ittc.ku.edu/resilinets

 * Information and Telecommunication Technology Center (ITTC)

 * and Department of Electrical Engineering and Computer Science

 * The University of Kansas Lawrence, KS USA.

 *

 * Work supported in part by NSF FIND (Future Internet Design) Program

 * under grant CNS-0626918 (Postmodern Internet Architecture),

 * NSF grant CNS-1050226 (Multilayer Network Resilience Analysis and Experimentation on GENI),

 * US Department of Defense (DoD), and ITTC at The University of Kansas.

 */

#include "dsr-rsendbuff.h"

#include <algorithm>

#include <functional>

#include "ns3/ipv4-route.h"

#include "ns3/socket.h"

#include "ns3/log.h"

NS_LOG_COMPONENT_DEFINE ("DsrSendBuffer");

namespace ns3 {

namespace dsr {

uint32_t

SendBuffer::GetSize ()

{

  Purge ();

  return m_sendBuffer.size ();

}

bool

SendBuffer::Enqueue (SendBuffEntry & entry)

{

  Purge ();

  for (std::vector<SendBuffEntry>::const_iterator i = m_sendBuffer.begin (); i

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

    {

      NS_LOG_INFO ("packet id " << i->GetPacket ()->GetUid () << " " << entry.GetPacket ()->GetUid ()

      if ((i->GetPacket ()->GetUid () == entry.GetPacket ()->GetUid ())

          && (i->GetDestination () == entry.GetDestination ()))

        {

          return false;

        }

    }

  entry.SetExpireTime (m_sendBufferTimeout);     // Initialize the send buffer timeout

  /*

   * Drop the most aged packet when buffer reaches to max

   */

  if (m_sendBuffer.size () >= m_maxLen)

    {

      Drop (m_sendBuffer.front (), "Drop the most aged packet");         // Drop the most aged packet

      m_sendBuffer.erase (m_sendBuffer.begin ());

    }

  // enqueue the entry

  m_sendBuffer.push_back (entry);

  return true;

}

void

SendBuffer::DropPacketWithDst (Ipv4Address dst)

{

  NS_LOG_FUNCTION (this << dst);

  Purge ();

  /*

   * Drop the packet with destination address dst

   */

  for (std::vector<SendBuffEntry>::iterator i = m_sendBuffer.begin (); i

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

    {

      if (IsEqual (*i, dst))

        {

          Drop (*i, "DropPacketWithDst");

        }

    }

  m_sendBuffer.erase (std::remove_if (m_sendBuffer.begin (), m_sendBuffer.end (),

                                      std::bind2nd (std::ptr_fun (SendBuffer::IsEqual), dst)), m_sendBuffer.end ());

}

bool

SendBuffer::Dequeue (Ipv4Address dst, SendBuffEntry & entry)

{

  Purge ();

  /*

   * Dequeue the entry with destination address dst

   */

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

    {

      if (i->GetDestination () == dst)

        {

          entry = *i;

          m_sendBuffer.erase (i);

          NS_LOG_DEBUG ("Packet size while dequeuing " << entry.GetPacket ()->GetSize ());

          return true;

        }

    }

  return false;

}

bool

SendBuffer::Find (Ipv4Address dst)

{

  /*

   * Make sure if the send buffer contains entry with certain dst

   */

  for (std::vector<SendBuffEntry>::const_iterator i = m_sendBuffer.begin (); i

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

    {

      if (i->GetDestination () == dst)

        {

          NS_LOG_DEBUG ("Found the packet");

          return true;

        }

    }

  return false;

}

struct IsExpired

{

  bool

  operator() (SendBuffEntry const & e) const

  {

    // NS_LOG_DEBUG("Expire time for packet in req queue: "<<e.GetExpireTime ());

    return (e.GetExpireTime () < Seconds (0));

  }

};

void

SendBuffer::Purge ()

{

  /*

   * Purge the buffer to eliminate expired entries

   */

  NS_LOG_DEBUG ("The send buffer size " << m_sendBuffer.size ());

  IsExpired pred;

  for (std::vector<SendBuffEntry>::iterator i = m_sendBuffer.begin (); i

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

    {

      if (pred (*i))

        {

          NS_LOG_DEBUG ("Dropping Queue Packets");

          Drop (*i, "Drop out-dated packet ");

        }

    }

  m_sendBuffer.erase (std::remove_if (m_sendBuffer.begin (), m_sendBuffer.end (), pred),

                      m_sendBuffer.end ());

}

void

SendBuffer::Drop (SendBuffEntry en, std::string reason)

{

  NS_LOG_LOGIC (reason << en.GetPacket ()->GetUid () << " " << en.GetDestination ());

//  en.GetErrorCallback () (en.GetPacket (), en.GetDestination (),

//     Socket::ERROR_NOROUTETOHOST);

  return;

}

}  // namespace dsr

}  // namespace ns3