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

/*

 * Copyright (c) 2006, 2009 INRIA

 * Copyright (c) 2009 MIRKO BANCHI

 *

 * 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: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 * Author: Mirko Banchi <mk.banchi@gmail.com>

 */

#include "ns3/log.h"

#include "ns3/assert.h"

#include "edca-txop-n.h"

#include "mac-low.h"

#include "dcf-manager.h"

#include "mac-tx-middle.h"

#include "wifi-mac-trailer.h"

#include "wifi-mac.h"

#include "random-stream.h"

#include "wifi-mac-queue.h"

#include "msdu-aggregator.h"

NS_LOG_COMPONENT_DEFINE ("EdcaTxopN");

#define MY_DEBUG(x) \

  NS_LOG_DEBUG (m_low->GetAddress () << " " << x)

namespace ns3 {

class EdcaTxopN::Dcf : public DcfState

{

public:

  Dcf (EdcaTxopN *txop)

    : m_txop (txop)

  {}

private:

  virtual void DoNotifyAccessGranted (void) {

    m_txop->NotifyAccessGranted ();

  }

  virtual void DoNotifyInternalCollision (void) {

    m_txop->NotifyInternalCollision ();

  }

  virtual void DoNotifyCollision (void) {

    m_txop->NotifyCollision ();

  }

  virtual void DoNotifyChannelSwitching (void) { 

    m_txop->NotifyChannelSwitching ();

  }

  EdcaTxopN *m_txop;

};

class EdcaTxopN::TransmissionListener : public MacLowTransmissionListener

{

public:

  TransmissionListener (EdcaTxopN *txop)

    : MacLowTransmissionListener (),

      m_txop (txop) {}

  virtual ~TransmissionListener () {}

  virtual void GotCts (double snr, WifiMode txMode) {

    m_txop->GotCts (snr, txMode);

  }

  virtual void MissedCts (void) {

    m_txop->MissedCts ();

  }

  virtual void GotAck (double snr, WifiMode txMode) {

    m_txop->GotAck (snr, txMode);

  }

  virtual void MissedAck (void) {

    m_txop->MissedAck ();

  }

  virtual void StartNext (void) {

    m_txop->StartNext ();

  }

  virtual void Cancel (void) {

    m_txop->Cancel ();

  }

private:

  EdcaTxopN *m_txop;

};

NS_OBJECT_ENSURE_REGISTERED (EdcaTxopN);

TypeId

EdcaTxopN::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::EdcaTxopN")

    .SetParent<Object> ()

    .AddConstructor<EdcaTxopN> ()

    ;

  return tid;

}

EdcaTxopN::EdcaTxopN ()

  : m_manager (0),

    m_currentPacket(0),

    m_aggregator (0)

{

  NS_LOG_FUNCTION (this);

  m_transmissionListener = new EdcaTxopN::TransmissionListener (this);

  m_dcf = new EdcaTxopN::Dcf (this);

  m_queue = CreateObject<WifiMacQueue> ();

  m_rng = new RealRandomStream ();

}

EdcaTxopN::~EdcaTxopN ()

{

  NS_LOG_FUNCTION (this);

}

void

EdcaTxopN::DoDispose (void)

{

  NS_LOG_FUNCTION (this);

  m_queue = 0;

  m_low = 0;

  m_stationManager = 0;

  delete m_transmissionListener;

  delete m_dcf;

  delete m_rng;

  m_transmissionListener = 0;

  m_dcf = 0;

  m_rng = 0;

  m_txMiddle = 0;

  m_aggregator = 0;

}

void

EdcaTxopN::SetManager (DcfManager *manager)

{

  NS_LOG_FUNCTION (this << manager);

  m_manager = manager;

  m_manager->Add (m_dcf);

}

void

EdcaTxopN::SetTxOkCallback (TxOk callback)

{

  m_txOkCallback = callback;

}

void 

EdcaTxopN::SetTxFailedCallback (TxFailed callback)

{

  m_txFailedCallback = callback;

}

void

EdcaTxopN::SetWifiRemoteStationManager (Ptr<WifiRemoteStationManager> remoteManager)

{

  NS_LOG_FUNCTION (this << remoteManager);

  m_stationManager = remoteManager;

}

void

EdcaTxopN::SetTypeOfStation (enum TypeOfStation type)

{

  NS_LOG_FUNCTION (this << type);

  m_typeOfStation = type;

}

enum TypeOfStation

EdcaTxopN::GetTypeOfStation (void) const

{

  return m_typeOfStation;

}

void 

EdcaTxopN::SetMaxQueueSize (uint32_t size)

{

  NS_LOG_FUNCTION (this << size);

  m_queue->SetMaxSize (size);

}

void

EdcaTxopN::SetMaxQueueDelay (Time delay)

{

  NS_LOG_FUNCTION (this << delay);

  m_queue->SetMaxDelay (delay);

}

void 

EdcaTxopN::SetMinCw (uint32_t minCw)

{

  NS_LOG_FUNCTION (this << minCw);

  m_dcf->SetCwMin (minCw);

}

void 

EdcaTxopN::SetMaxCw (uint32_t maxCw)

{

  NS_LOG_FUNCTION (this << maxCw);

  m_dcf->SetCwMax (maxCw);

}

void 

EdcaTxopN::SetAifsn (uint32_t aifsn)

{

  NS_LOG_FUNCTION (this << aifsn);

  m_dcf->SetAifsn (aifsn);

}

uint32_t 

EdcaTxopN::GetMinCw (void) const

{

  return m_dcf->GetCwMin ();

}

uint32_t 

EdcaTxopN::GetMaxCw (void) const

{

  return m_dcf->GetCwMax ();

}

uint32_t 

EdcaTxopN::GetAifsn (void) const

{

  return m_dcf->GetAifsn ();

}

void

EdcaTxopN::SetTxMiddle (MacTxMiddle *txMiddle)

{

  m_txMiddle = txMiddle;

}

Ptr<MacLow>

EdcaTxopN::Low (void)

{

  return m_low;

}

void

EdcaTxopN::SetLow(Ptr<MacLow> low)

{

  NS_LOG_FUNCTION (this << low);

  m_low = low;

}

bool

EdcaTxopN::NeedsAccess (void) const

{

  return !m_queue->IsEmpty () || m_currentPacket != 0;

}

void

EdcaTxopN::NotifyAccessGranted (void)

{

  NS_LOG_FUNCTION (this);

  if (m_currentPacket == 0)

    {

      if (m_queue->IsEmpty ())

        {

          MY_DEBUG ("queue is empty");

          return; 

        }

      m_currentPacket = m_queue->Dequeue (&m_currentHdr);

      NS_ASSERT (m_currentPacket != 0);

      uint16_t sequence = m_txMiddle->GetNextSequenceNumberfor (&m_currentHdr);

      m_currentHdr.SetSequenceNumber (sequence);

      m_currentHdr.SetFragmentNumber (0);

      m_currentHdr.SetNoMoreFragments ();

      m_currentHdr.SetNoRetry ();

      m_fragmentNumber = 0;

      MY_DEBUG ("dequeued size="<<m_currentPacket->GetSize ()<<

                ", to="<<m_currentHdr.GetAddr1 ()<<

                ", seq="<<m_currentHdr.GetSequenceControl ());

    }

  MacLowTransmissionParameters params;

  params.DisableOverrideDurationId ();

  if (m_currentHdr.GetAddr1 ().IsBroadcast ()) 

    {

      params.DisableRts ();

      params.DisableAck ();

      params.DisableNextData ();

      m_low->StartTransmission (m_currentPacket,

                                 &m_currentHdr,

                                 params,

                                 m_transmissionListener);

      m_currentPacket = 0;

      m_dcf->ResetCw ();

      m_dcf->StartBackoffNow (m_rng->GetNext (0, m_dcf->GetCw ()));

      StartAccessIfNeeded ();

      MY_DEBUG ("tx broadcast");

    }

  else

    {

      params.EnableAck ();

      if (NeedFragmentation () && ((m_currentHdr.IsQosData () &&

                                    !m_currentHdr.IsQosAmsdu ()) ||

                                    m_currentHdr.IsData ()))

        {

          params.DisableRts ();

          WifiMacHeader hdr;

          Ptr<Packet> fragment = GetFragmentPacket (&hdr);

          if (IsLastFragment ()) 

            {

              MY_DEBUG ("fragmenting last fragment size=" << fragment->GetSize ());

              params.DisableNextData ();

            } 

          else 

            {

              MY_DEBUG ("fragmenting size=" << fragment->GetSize ());

              params.EnableNextData (GetNextFragmentSize ());

            }

          m_low->StartTransmission (fragment, &hdr, params, 

                                     m_transmissionListener);

        }

      else

        {

          WifiMacHeader peekedHdr;

          if (m_currentHdr.IsQosData () &&

              m_queue->PeekByTidAndAddress (&peekedHdr, m_currentHdr.GetQosTid (), 

                                            WifiMacHeader::ADDR1, m_currentHdr.GetAddr1 ()) &&

              !m_currentHdr.GetAddr1 ().IsBroadcast () &&

              m_aggregator != 0)

            {

              /* here is performed aggregation */

              Ptr<Packet> currentAggregatedPacket = Create<Packet> ();

              m_aggregator->Aggregate (m_currentPacket, currentAggregatedPacket,

                                       MapSrcAddressForAggregation (peekedHdr),

                                       MapDestAddressForAggregation (peekedHdr));

              bool aggregated = false;

              bool isAmsdu = false;

              Ptr<const Packet> peekedPacket = m_queue->PeekByTidAndAddress (&peekedHdr, m_currentHdr.GetQosTid (), 

                                                                       WifiMacHeader::ADDR1, 

                                                                       m_currentHdr.GetAddr1 ());

              while (peekedPacket != 0)

                {

                  aggregated = m_aggregator->Aggregate (peekedPacket, currentAggregatedPacket,

                                                        MapSrcAddressForAggregation (peekedHdr),

                                                        MapDestAddressForAggregation (peekedHdr));

                  if (aggregated) 

                    {

                      isAmsdu = true;

                      m_queue->Remove (peekedPacket);

                    }

                  else

                    {

                      break;

                    }

                  peekedPacket = m_queue->PeekByTidAndAddress (&peekedHdr, m_currentHdr.GetQosTid (), 

                                                               WifiMacHeader::ADDR1, m_currentHdr.GetAddr1 ());

                }

              if (isAmsdu)

                {

                  m_currentHdr.SetQosAmsdu ();

                  m_currentHdr.SetAddr3 (m_low->GetBssid ());

                  m_currentPacket = currentAggregatedPacket;

                  currentAggregatedPacket = 0;

                  MY_DEBUG ("tx unicast A-MSDU");

                }

            }

          if (NeedRts ())

            {

              params.EnableRts ();

              MY_DEBUG ("tx unicast rts");

            } 

          else 

            {

              params.DisableRts ();

              MY_DEBUG ("tx unicast");

            }

          params.DisableNextData ();

          m_low->StartTransmission (m_currentPacket, &m_currentHdr,

                                    params, m_transmissionListener);

        }

    }

}

void EdcaTxopN::NotifyInternalCollision (void)

{

  NS_LOG_FUNCTION (this);

  NotifyCollision ();

}

void

EdcaTxopN::NotifyCollision (void)

{

  NS_LOG_FUNCTION (this);

  m_dcf->StartBackoffNow (m_rng->GetNext (0, m_dcf->GetCw ()));

  RestartAccessIfNeeded ();

}

void 

EdcaTxopN::GotCts (double snr, WifiMode txMode)

{

  NS_LOG_FUNCTION (this << snr << txMode);

  MY_DEBUG ("got cts");

}

void 

EdcaTxopN::MissedCts (void)

{

  NS_LOG_FUNCTION (this);

  MY_DEBUG ("missed cts");

  if (!NeedRtsRetransmission ())

    {

      MY_DEBUG ("Cts Fail");

      if (!m_txFailedCallback.IsNull ()) 

        {

          m_txFailedCallback (m_currentHdr);

        }

      // to reset the dcf.

      m_currentPacket = 0;

      m_dcf->ResetCw ();

    } 

  else 

    {

      m_dcf->UpdateFailedCw ();

    }

  m_dcf->StartBackoffNow (m_rng->GetNext (0, m_dcf->GetCw ()));

  RestartAccessIfNeeded ();

}

void 

EdcaTxopN::NotifyChannelSwitching (void)

{

  m_queue->Flush();

  m_currentPacket = 0;

}

void

EdcaTxopN::Queue (Ptr<const Packet> packet, const WifiMacHeader &hdr)

{

  NS_LOG_FUNCTION (this << packet << &hdr);

  WifiMacTrailer fcs;

  uint32_t fullPacketSize = hdr.GetSerializedSize () + packet->GetSize () + fcs.GetSerializedSize ();

  m_queue->Enqueue (packet, hdr);

  StartAccessIfNeeded ();

}

void

EdcaTxopN::GotAck (double snr, WifiMode txMode)

{

  NS_LOG_FUNCTION (this << snr << txMode);

  if (!NeedFragmentation () ||

      IsLastFragment () ||

      m_currentHdr.IsQosAmsdu ()) 

    {

      MY_DEBUG ("got ack. tx done.");

      if (!m_txOkCallback.IsNull ())

        {

           m_txOkCallback (m_currentHdr);

        }

      m_currentPacket = 0;

      m_dcf->ResetCw ();

      m_dcf->StartBackoffNow (m_rng->GetNext (0, m_dcf->GetCw ()));

      RestartAccessIfNeeded ();

    } 

  else 

    {

      MY_DEBUG ("got ack. tx not done, size="<<m_currentPacket->GetSize ());

    }

}

void

EdcaTxopN::MissedAck (void)

{

  NS_LOG_FUNCTION (this);

  MY_DEBUG ("missed ack");

  if (!NeedDataRetransmission ()) 

    {

      MY_DEBUG ("Ack Fail");

      if (!m_txFailedCallback.IsNull ()) 

        {

          m_txFailedCallback (m_currentHdr);

        }

      // to reset the dcf.

      m_currentPacket = 0;

      m_dcf->ResetCw ();

    } 

  else 

    {

      MY_DEBUG ("Retransmit");

      m_currentHdr.SetRetry ();

      m_dcf->UpdateFailedCw ();

    }

  m_dcf->StartBackoffNow (m_rng->GetNext (0, m_dcf->GetCw ()));

  RestartAccessIfNeeded ();

}

Ptr<MsduAggregator>

EdcaTxopN::GetMsduAggregator (void) const

{

  return m_aggregator;

}

void

EdcaTxopN::RestartAccessIfNeeded (void)

{

  NS_LOG_FUNCTION (this);

  if ((m_currentPacket != 0 ||

       !m_queue->IsEmpty ()) &&

       !m_dcf->IsAccessRequested ())

    {

      m_manager->RequestAccess (m_dcf);

    }

}

void

EdcaTxopN::StartAccessIfNeeded (void)

{

  NS_LOG_FUNCTION (this);

  if (m_currentPacket == 0 &&

      !m_queue->IsEmpty () &&

      !m_dcf->IsAccessRequested ())