/* -*-  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/simulator.h"

#include "ns3/string.h"

#include "ns3/pointer.h"

#include "qos-tag.h"

#include "edca-txop-n.h"

#include "qsta-wifi-mac.h"

#include "mac-low.h"

#include "dcf-manager.h"

#include "mac-rx-middle.h"

#include "mac-tx-middle.h"

#include "wifi-mac-header.h"

#include "msdu-aggregator.h"

#include "amsdu-subframe-header.h"

#include "mgt-headers.h"

NS_LOG_COMPONENT_DEFINE ("QstaWifiMac");

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (QstaWifiMac);

TypeId

QstaWifiMac::GetTypeId (void)

{

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

    .SetParent<WifiMac> ()

    .AddConstructor<QstaWifiMac> ()

    .AddAttribute ("ProbeRequestTimeout", "The interval between two consecutive probe request attempts.",

                   TimeValue (Seconds (0.05)),

                   MakeTimeAccessor (&QstaWifiMac::m_probeRequestTimeout),

                   MakeTimeChecker ())

    .AddAttribute ("AssocRequestTimeout", "The interval between two consecutive assoc request attempts.",

                   TimeValue (Seconds (0.5)),

                   MakeTimeAccessor (&QstaWifiMac::m_assocRequestTimeout),

                   MakeTimeChecker ())

    .AddAttribute ("MaxMissedBeacons", 

                   "Number of beacons which much be consecutively missed before "

                   "we attempt to restart association.",

                   UintegerValue (10),

                   MakeUintegerAccessor (&QstaWifiMac::m_maxMissedBeacons),

                   MakeUintegerChecker<uint32_t> ())

    .AddAttribute ("ActiveProbing", "If true, we send probe requests. If false, we don't.",

                   BooleanValue (false),

                   MakeBooleanAccessor (&QstaWifiMac::SetActiveProbing),

                   MakeBooleanChecker ())

    .AddAttribute ("VO_EdcaTxopN",

                   "Queue that manages packets belonging to AC_VO access class",

                   PointerValue (),

                   MakePointerAccessor(&QstaWifiMac::GetVOQueue),

                   MakePointerChecker<EdcaTxopN> ())

    .AddAttribute ("VI_EdcaTxopN",

                   "Queue that manages packets belonging to AC_VI access class",

                   PointerValue (),

                   MakePointerAccessor(&QstaWifiMac::GetVIQueue),

                   MakePointerChecker<EdcaTxopN> ())

    .AddAttribute ("BE_EdcaTxopN",

                   "Queue that manages packets belonging to AC_BE access class",

                   PointerValue (),

                   MakePointerAccessor(&QstaWifiMac::GetBEQueue),

                   MakePointerChecker<EdcaTxopN> ())

    .AddAttribute ("BK_EdcaTxopN",

                   "Queue that manages packets belonging to AC_BK access class",

                   PointerValue (),

                   MakePointerAccessor(&QstaWifiMac::GetBKQueue),

                   MakePointerChecker<EdcaTxopN> ())

    ;

  return tid;

}

QstaWifiMac::QstaWifiMac ()

  : m_state (BEACON_MISSED),

    m_probeRequestEvent (),

    m_assocRequestEvent (),

    m_beaconWatchdogEnd (Seconds (0.0))

{

  NS_LOG_FUNCTION (this);

  m_rxMiddle = new MacRxMiddle ();

  m_rxMiddle->SetForwardCallback (MakeCallback (&QstaWifiMac::Receive, this));

  /*TxMiddle can be shared between all queues */

  m_txMiddle= new MacTxMiddle ();

  m_low = CreateObject<MacLow> ();

  m_low->SetRxCallback (MakeCallback (&MacRxMiddle::Receive, m_rxMiddle));

  m_dcfManager = new DcfManager ();

  m_dcfManager->SetupLowListener (m_low);

  SetQueue (AC_VO);

  SetQueue (AC_VI);

  SetQueue (AC_BE);

  SetQueue (AC_BK);

}

QstaWifiMac::~QstaWifiMac ()

{

  NS_LOG_FUNCTION (this);

}

void

QstaWifiMac::DoDispose ()

{

  NS_LOG_FUNCTION (this);

  delete m_rxMiddle;

  delete m_txMiddle;

  delete m_dcfManager;

  m_low->Dispose ();

  m_rxMiddle = 0;

  m_txMiddle = 0;

  m_low = 0;

  m_phy = 0;

  m_dcfManager = 0;

  m_stationManager = 0;

  for (Queues::iterator i = m_queues.begin (); i != m_queues.end (); ++i)

    {

      (*i).second = 0;

    }

  WifiMac::DoDispose ();

}

void

QstaWifiMac::SetSlot (Time slotTime)

{

  NS_LOG_FUNCTION (this << slotTime);

  m_dcfManager->SetSlot (slotTime);

  m_low->SetSlotTime (slotTime);

}

void 

QstaWifiMac::SetSifs (Time sifs)

{

  NS_LOG_FUNCTION (this << sifs);

  m_dcfManager->SetSifs (sifs);

  m_low->SetSifs (sifs);

}

void

QstaWifiMac::SetEifsNoDifs (Time eifsNoDifs)

{

  NS_LOG_FUNCTION (this << eifsNoDifs);

  m_dcfManager->SetEifsNoDifs (eifsNoDifs);

}

void

QstaWifiMac::SetAckTimeout (Time ackTimeout)

{

  m_low->SetAckTimeout (ackTimeout);

}

void

QstaWifiMac::SetCtsTimeout (Time ctsTimeout)

{

  m_low->SetCtsTimeout (ctsTimeout);

}

void

QstaWifiMac::SetPifs (Time pifs)

{

  m_low->SetPifs (pifs);

}

Time

QstaWifiMac::GetSlot (void) const

{

  return m_low->GetSlotTime ();

}

Time

QstaWifiMac::GetSifs (void) const

{

  return m_low->GetSifs ();

}

Time 

QstaWifiMac::GetEifsNoDifs (void) const

{

  return m_dcfManager->GetEifsNoDifs ();

}

Time

QstaWifiMac::GetAckTimeout (void) const

{

 return m_low->GetAckTimeout ();

}

Time

QstaWifiMac::GetCtsTimeout (void) const

{

  return m_low->GetCtsTimeout ();

}

Time 

QstaWifiMac::GetPifs (void) const

{

  return m_low->GetPifs ();

}

void

QstaWifiMac::SetWifiPhy (Ptr<WifiPhy> phy)

{

  m_phy = phy;

  m_dcfManager->SetupPhyListener (phy);

  m_low->SetPhy (phy);

}

void

QstaWifiMac::SetWifiRemoteStationManager (Ptr<WifiRemoteStationManager> stationManager)

{

  m_stationManager = stationManager;

  m_queues[AC_VO]->SetWifiRemoteStationManager (stationManager);

  m_queues[AC_VI]->SetWifiRemoteStationManager (stationManager);

  m_queues[AC_BE]->SetWifiRemoteStationManager (stationManager);

  m_queues[AC_BK]->SetWifiRemoteStationManager (stationManager);

  m_low->SetWifiRemoteStationManager (stationManager);

}

void

QstaWifiMac::SetForwardUpCallback (Callback<void,Ptr<Packet>, Mac48Address, Mac48Address> upCallback)

{

  m_forwardUp = upCallback;

}

void

QstaWifiMac::SetLinkUpCallback (Callback<void> linkUp)

{

  m_linkUp = linkUp;

}

void

QstaWifiMac::SetLinkDownCallback (Callback<void> linkDown)

{

  m_linkDown = linkDown;

}

Mac48Address

QstaWifiMac::GetAddress (void) const

{

  return m_low->GetAddress ();

}

Ssid

QstaWifiMac::GetSsid (void) const

{

  return m_ssid;

}

Mac48Address

QstaWifiMac::GetBssid () const

{

  return m_low->GetBssid ();

}

void

QstaWifiMac::SetAddress (Mac48Address address)

{

  NS_LOG_FUNCTION (this << address);

  m_low->SetAddress (address);

}

void

QstaWifiMac::SetSsid (Ssid ssid)

{

  NS_LOG_FUNCTION (this << ssid);

  m_ssid = ssid;

}

void

QstaWifiMac::SetMaxMissedBeacons (uint32_t missed)

{

  NS_LOG_FUNCTION (this << missed);

  m_maxMissedBeacons = missed;

}

void

QstaWifiMac::SetProbeRequestTimeout (Time timeout)

{

  NS_LOG_FUNCTION (this << timeout);

  m_probeRequestTimeout = timeout;

}

void

QstaWifiMac::SetAssocRequestTimeout (Time timeout)

{

  NS_LOG_FUNCTION (this << timeout);

  m_assocRequestTimeout = timeout;

}

void

QstaWifiMac::StartActiveAssociation (void)

{

  NS_LOG_FUNCTION (this);

  TryToEnsureAssociated ();

}

Mac48Address

QstaWifiMac::GetBroadcastBssid (void)

{

  return Mac48Address::GetBroadcast ();

}

void 

QstaWifiMac::SetBssid (Mac48Address bssid)

{

  NS_LOG_FUNCTION (this << bssid);

  m_low->SetBssid (bssid);

}

void

QstaWifiMac::SetActiveProbing (bool enable)

{

  NS_LOG_FUNCTION (this << enable);

  if (enable)

    {

      TryToEnsureAssociated ();

    }

  else

    {

      m_probeRequestEvent.Cancel ();

    }

}

void

QstaWifiMac::ForwardUp (Ptr<Packet> packet, Mac48Address from, Mac48Address to)

{

  NS_LOG_FUNCTION (this << packet << from << to);

  m_forwardUp (packet, from, to);

}

void

QstaWifiMac::SendProbeRequest (void)

{

  NS_LOG_FUNCTION (this);

  WifiMacHeader hdr;

  hdr.SetProbeReq ();

  hdr.SetAddr1 (GetBroadcastBssid ());

  hdr.SetAddr2 (GetAddress ());

  hdr.SetAddr3 (GetBroadcastBssid ());

  hdr.SetDsNotFrom ();

  hdr.SetDsNotTo ();

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

  MgtProbeRequestHeader probe;

  probe.SetSsid (GetSsid ());

  probe.SetSupportedRates (GetSupportedRates ());

  packet->AddHeader (probe);

  /* Which is correct queue for management frames ? */

  m_queues[AC_VO]->Queue (packet, hdr);

  m_probeRequestEvent = Simulator::Schedule (m_probeRequestTimeout,

                                             &QstaWifiMac::ProbeRequestTimeout, this);

}

void

QstaWifiMac::SendAssociationRequest (void)

{

  NS_LOG_FUNCTION (this << GetBssid ());

  WifiMacHeader hdr;

  hdr.SetAssocReq ();

  hdr.SetAddr1 (GetBssid ());

  hdr.SetAddr2 (GetAddress ());

  hdr.SetAddr3 (GetBssid ());

  hdr.SetDsNotFrom ();

  hdr.SetDsNotTo ();

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

  MgtAssocRequestHeader assoc;

  assoc.SetSsid (GetSsid ());

  assoc.SetSupportedRates (GetSupportedRates ());

  packet->AddHeader (assoc);

  /* Which is correct queue for management frames ? */

  m_queues[AC_VO]->Queue (packet, hdr);

  m_assocRequestEvent = Simulator::Schedule (m_assocRequestTimeout,

                                             &QstaWifiMac::AssocRequestTimeout, this);

}

void

QstaWifiMac::TryToEnsureAssociated (void)

{

  NS_LOG_FUNCTION (this);

  switch (m_state) {

  case ASSOCIATED:

    return;

    break;

  case WAIT_PROBE_RESP:

    /* we have sent a probe request earlier so we

       do not need to re-send a probe request immediately.

       We just need to wait until probe-request-timeout

       or until we get a probe response

     */

    break;

  case BEACON_MISSED:

    /* we were associated but we missed a bunch of beacons

     * so we should assume we are not associated anymore.

     * We try to initiate a probe request now.

     */

    m_linkDown ();

    m_state = WAIT_PROBE_RESP;

    SendProbeRequest ();

    break;

  case WAIT_ASSOC_RESP:

    /* we have sent an assoc request so we do not need to

       re-send an assoc request right now. We just need to

       wait until either assoc-request-timeout or until

       we get an assoc response.

     */

    break;

  case REFUSED:

    /* we have sent an assoc request and received a negative

       assoc resp. We wait until someone restarts an 

       association with a given ssid.

     */

    break;

  }

}

void

QstaWifiMac::AssocRequestTimeout (void)

{

  NS_LOG_FUNCTION (this);

  m_state = WAIT_ASSOC_RESP;

  SendAssociationRequest ();

}

void

QstaWifiMac::ProbeRequestTimeout (void)

{

  NS_LOG_FUNCTION (this);

  m_state = WAIT_PROBE_RESP;

  SendProbeRequest ();

}

void

QstaWifiMac::MissedBeacons (void)

{

  NS_LOG_FUNCTION (this);

  if (m_beaconWatchdogEnd > Simulator::Now ())

    {

      m_beaconWatchdog = Simulator::Schedule (m_beaconWatchdogEnd - Simulator::Now (),

                                              &QstaWifiMac::MissedBeacons, this);

      return;

    }

  NS_LOG_DEBUG ("beacon missed");

  m_state = BEACON_MISSED;

  TryToEnsureAssociated ();

}

void

QstaWifiMac::RestartBeaconWatchdog (Time delay)

{

  NS_LOG_FUNCTION (this << delay);

  m_beaconWatchdogEnd = std::max (Simulator::Now () + delay, m_beaconWatchdogEnd);

  if (Simulator::GetDelayLeft (m_beaconWatchdog) < delay &&

                               m_beaconWatchdog.IsExpired ())

    {

      NS_LOG_DEBUG ("really restart watchdog.");

      m_beaconWatchdog = Simulator::Schedule (delay, &QstaWifiMac::MissedBeacons, this);

    }

}

bool

QstaWifiMac::IsAssociated (void) const

{

  return m_state == ASSOCIATED;

}

bool 

QstaWifiMac::IsWaitAssocResp (void) const

{

  return m_state == WAIT_ASSOC_RESP;

}

void

QstaWifiMac::Enqueue (Ptr<const Packet> packet, Mac48Address to)

{

  NS_LOG_FUNCTION (this << packet << to);

  if (!IsAssociated ()) 

    {

      TryToEnsureAssociated ();

      return;

    }

  WifiMacHeader hdr;

  hdr.SetType (WIFI_MAC_QOSDATA);

  hdr.SetQosAckPolicy (WifiMacHeader::NORMAL_ACK);

  hdr.SetQosNoAmsdu ();

  hdr.SetQosNoEosp ();

  /* Transmission of multiple frames in the same 

     Txop is not supported for now */

  hdr.SetQosTxopLimit (0);

  hdr.SetAddr1 (GetBssid ());

  hdr.SetAddr2 (m_low->GetAddress ());

  hdr.SetAddr3 (to);

  hdr.SetDsNotFrom ();

  hdr.SetDsTo ();

  uint8_t tid = QosUtilsGetTidForPacket (packet);

  if (tid < 8)

    {

      hdr.SetQosTid (tid);

      AccessClass ac = QosUtilsMapTidToAc (tid);

      m_queues[ac]->Queue (packet, hdr);

    }