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

/*

 * Copyright (c) 2005,2006,2007 INRIA

 *

 * 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>

 */

#include "wifi-remote-station-manager.h"

#include "ns3/assert.h"

#include "ns3/log.h"

#include "ns3/tag.h"

#include "ns3/boolean.h"

#include "ns3/uinteger.h"

#include "ns3/wifi-phy.h"

#include "ns3/trace-source-accessor.h"

NS_LOG_COMPONENT_DEFINE ("WifiRemoteStationManager");

namespace ns3 {

/**

 * _all_ broadcast and multicast frames are transmitted

 * at the same constant default rate because since we don't

 * have any kind of feedback from their transmission,

 * we cannot adjust the rate, so, we pick one which ensures

 * that all frames reach destination.

 */

class NonUnicastWifiRemoteStation : public WifiRemoteStation

{

public:

  NonUnicastWifiRemoteStation (Ptr<WifiRemoteStationManager> stations);

protected:

  virtual void DoReportRxOk (double rxSnr, WifiMode txMode);

  virtual void DoReportRtsFailed (void);

  virtual void DoReportDataFailed (void);

  virtual void DoReportRtsOk (double ctsSnr, WifiMode ctsMode, double rtsSnr);

  virtual void DoReportDataOk (double ackSnr, WifiMode ackMode, double dataSnr);

  virtual void DoReportFinalRtsFailed (void);

  virtual void DoReportFinalDataFailed (void);

private:

  virtual Ptr<WifiRemoteStationManager> GetManager (void) const;

  virtual WifiMode DoGetDataMode (uint32_t size);

  virtual WifiMode DoGetRtsMode (void);

  Ptr<WifiRemoteStationManager> m_stations;

};

NonUnicastWifiRemoteStation::NonUnicastWifiRemoteStation (Ptr<WifiRemoteStationManager> stations)

  : m_stations (stations)

{

  RecordDisassociated ();

}

void 

NonUnicastWifiRemoteStation::DoReportRxOk (double rxSnr, WifiMode txMode)

{

  NS_ASSERT (false);

}

void 

NonUnicastWifiRemoteStation::DoReportRtsFailed (void)

{

  NS_ASSERT (false);

}

void 

NonUnicastWifiRemoteStation::DoReportDataFailed (void)

{

  NS_ASSERT (false);

}

void 

NonUnicastWifiRemoteStation::DoReportRtsOk (double ctsSnr, WifiMode ctsMode, double rtsSnr)

{

  NS_ASSERT (false);

}

void 

NonUnicastWifiRemoteStation::DoReportDataOk (double ackSnr, WifiMode ackMode, double dataSnr)

{

  NS_ASSERT (false);

}

void 

NonUnicastWifiRemoteStation::DoReportFinalRtsFailed (void)

{}

void 

NonUnicastWifiRemoteStation::DoReportFinalDataFailed (void)

{}

WifiMode 

NonUnicastWifiRemoteStation::DoGetDataMode (uint32_t size)

{

  WifiMode mode = m_stations->GetNonUnicastMode ();

  NS_LOG_DEBUG ("non-unicast size="<<size<<", mode="<<mode);

  return mode;

}

WifiMode 

NonUnicastWifiRemoteStation::DoGetRtsMode (void)

{

  NS_ASSERT (false);

  // theoretically, no rts for broadcast/multicast packets.

  return m_stations->GetBasicMode (0);

}

Ptr<WifiRemoteStationManager>

NonUnicastWifiRemoteStation::GetManager (void) const

{

  return m_stations;

}

} // namespace ns3

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (WifiRemoteStationManager);

TypeId 

WifiRemoteStationManager::GetTypeId (void)

{

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

    .SetParent<Object> ()

    .AddAttribute ("IsLowLatency", "If true, we attempt to modelize a so-called low-latency device: a device"

                   " where decisions about tx parameters can be made on a per-packet basis and feedback about the"

                   " transmission of each packet is obtained before sending the next. Otherwise, we modelize a "

                   " high-latency device, that is a device where we cannot update our decision about tx parameters"

                   " after every packet transmission.",

                   BooleanValue (true),

                   MakeBooleanAccessor (&WifiRemoteStationManager::m_isLowLatency),

                   MakeBooleanChecker ())

    .AddAttribute ("MaxSsrc", "The maximum number of retransmission attempts for an RTS. This value"

                   " will not have any effect on some rate control algorithms.",

                   UintegerValue (7),

                   MakeUintegerAccessor (&WifiRemoteStationManager::m_maxSsrc),

                   MakeUintegerChecker<uint32_t> ())

    .AddAttribute ("MaxSlrc", "The maximum number of retransmission attempts for a DATA packet. This value"

                   " will not have any effect on some rate control algorithms.",

                   UintegerValue (7),

                   MakeUintegerAccessor (&WifiRemoteStationManager::m_maxSlrc),

                   MakeUintegerChecker<uint32_t> ())

    .AddAttribute ("RtsCtsThreshold", "If a data packet is bigger than this value, we use an RTS/CTS handshake"

                   " before sending the data. This value will not have any effect on some rate control algorithms.",

                   UintegerValue (1500),

                   MakeUintegerAccessor (&WifiRemoteStationManager::m_rtsCtsThreshold),

                   MakeUintegerChecker<uint32_t> ())

    .AddAttribute ("FragmentationThreshold", "If a data packet is bigger than this value, we fragment it such that"

                   " the size of the fragments are equal or smaller than this value. This value will not have any effect"

                   " on some rate control algorithms.",

                   UintegerValue (1500),

                   MakeUintegerAccessor (&WifiRemoteStationManager::m_fragmentationThreshold),

                   MakeUintegerChecker<uint32_t> ())

    .AddAttribute ("NonUnicastMode", "Wifi mode used for non-unicast transmissions.",

                   WifiModeValue (),

                   MakeWifiModeAccessor (&WifiRemoteStationManager::m_nonUnicastMode),

                   MakeWifiModeChecker ())

    ;

  return tid;

}

WifiRemoteStationManager::WifiRemoteStationManager ()

  : m_nonUnicast (new NonUnicastWifiRemoteStation (this))

{}

WifiRemoteStationManager::~WifiRemoteStationManager ()

{

}

void 

WifiRemoteStationManager::DoDispose (void)

{

  for (Stations::const_iterator i = m_stations.begin (); i != m_stations.end (); i++) 

    {

      delete (*i).second;

    }

  m_stations.clear ();

  delete m_nonUnicast;

}

void

WifiRemoteStationManager::SetupPhy (Ptr<WifiPhy> phy)

{

  m_defaultTxMode = phy->GetMode (0);

  Reset ();

}

uint32_t 

WifiRemoteStationManager::GetMaxSsrc (void) const

{

  return m_maxSsrc;

}

uint32_t 

WifiRemoteStationManager::GetMaxSlrc (void) const

{

  return m_maxSlrc;

}

uint32_t 

WifiRemoteStationManager::GetRtsCtsThreshold (void) const

{

  return m_rtsCtsThreshold;

}

uint32_t 

WifiRemoteStationManager::GetFragmentationThreshold (void) const

{

  return m_fragmentationThreshold;

}

void 

WifiRemoteStationManager::SetMaxSsrc (uint32_t maxSsrc)

{

  m_maxSsrc = maxSsrc;

}

void 

WifiRemoteStationManager::SetMaxSlrc (uint32_t maxSlrc)

{

  m_maxSlrc = maxSlrc;

}

void 

WifiRemoteStationManager::SetRtsCtsThreshold (uint32_t threshold)

{

  m_rtsCtsThreshold = threshold;

}

void 

WifiRemoteStationManager::SetFragmentationThreshold (uint32_t threshold)

{

  m_fragmentationThreshold = threshold;

} 

WifiRemoteStation *

WifiRemoteStationManager::Lookup (Mac48Address address)

{

  if (address.IsGroup ())

    {

      return m_nonUnicast;

    }

  for (Stations::const_iterator i = m_stations.begin (); i != m_stations.end (); i++) 

    {

      if ((*i).first == address)

        {

          return (*i).second;

        }

    }

  WifiRemoteStation *station = CreateStation ();

  station->Reset ();

  m_stations.push_back (std::make_pair (address, station));

  return station;

}

WifiRemoteStation *

WifiRemoteStationManager::LookupNonUnicast (void)

{

  return m_nonUnicast;

}

WifiMode 

WifiRemoteStationManager::GetDefaultMode (void) const

{

  return m_defaultTxMode;

}

void

WifiRemoteStationManager::Reset (void)

{

  for (Stations::const_iterator i = m_stations.begin (); i != m_stations.end (); i++)

    {

      delete i->second;

    }

  m_stations.clear ();

  m_basicModes.clear ();

  m_basicModes.push_back (m_defaultTxMode);

  NS_ASSERT (m_defaultTxMode.IsMandatory ());

}

void 

WifiRemoteStationManager::AddBasicMode (WifiMode mode)

{

  for (uint32_t i = 0; i < GetNBasicModes (); i++)

    {

      if (GetBasicMode (i) == mode)

        {

          return;

        }

    }

  m_basicModes.push_back (mode);

}

uint32_t 

WifiRemoteStationManager::GetNBasicModes (void) const

{

  return m_basicModes.size ();

}

WifiMode 

WifiRemoteStationManager::GetBasicMode (uint32_t i) const

{

  NS_ASSERT (i < m_basicModes.size ());

  return m_basicModes[i];

}

WifiRemoteStationManager::BasicModesIterator 

WifiRemoteStationManager::BeginBasicModes (void) const

{

  return m_basicModes.begin ();

}

WifiRemoteStationManager::BasicModesIterator 

WifiRemoteStationManager::EndBasicModes (void) const

{

  return m_basicModes.end ();

}

bool

WifiRemoteStationManager::IsLowLatency (void) const

{

  return m_isLowLatency;

}

WifiMode

WifiRemoteStationManager::GetNonUnicastMode (void) const

{

  if (m_nonUnicastMode == WifiMode ())

    return GetBasicMode(0);

  else

    return m_nonUnicastMode;

}

} // namespace ns3

/***************************************************************

 *           Packet Mode Tagger

 ***************************************************************/ 

namespace ns3 {

class TxModeTag : public Tag

{

public:

  TxModeTag ();

  TxModeTag (WifiMode rtsMode, WifiMode dataMode);

  WifiMode GetRtsMode (void) const;

  WifiMode GetDataMode (void) const;

  static TypeId GetTypeId (void);

  virtual TypeId GetInstanceTypeId (void) const;

  virtual uint32_t GetSerializedSize (void) const;

  virtual void Serialize (TagBuffer i) const;

  virtual void Deserialize (TagBuffer i);

  virtual void Print (std::ostream &os) const;

private:

  WifiMode m_rtsMode;

  WifiMode m_dataMode;

};

TxModeTag::TxModeTag ()

{}

TxModeTag::TxModeTag (WifiMode rtsMode, WifiMode dataMode)

  : m_rtsMode (rtsMode),

    m_dataMode (dataMode)

{}

WifiMode 

TxModeTag::GetRtsMode (void) const

{

  return m_rtsMode;

}

WifiMode 

TxModeTag::GetDataMode (void) const

{

  return m_dataMode;

}

TypeId 

TxModeTag::GetTypeId (void)

{

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

    .SetParent<Tag> ()

    .AddConstructor<TxModeTag> ()

    .AddAttribute ("RtsTxMode", 

                   "Tx mode of rts to use later",

                   EmptyAttributeValue (),

                   MakeWifiModeAccessor (&TxModeTag::GetRtsMode),

                   MakeWifiModeChecker ())

    .AddAttribute ("DataTxMode", 

                   "Tx mode of data to use later",

                   EmptyAttributeValue (),

                   MakeWifiModeAccessor (&TxModeTag::GetDataMode),

                   MakeWifiModeChecker ())

    ;

  return tid;

}

TypeId 

TxModeTag::GetInstanceTypeId (void) const

{

  return GetTypeId ();

}

uint32_t 

TxModeTag::GetSerializedSize (void) const

{

  return sizeof (WifiMode) * 2;

}

void 

TxModeTag::Serialize (TagBuffer i) const

{

  i.Write ((uint8_t *)&m_rtsMode, sizeof (WifiMode));

  i.Write ((uint8_t *)&m_dataMode, sizeof (WifiMode));

}

void 

TxModeTag::Deserialize (TagBuffer i)

{

  i.Read ((uint8_t *)&m_rtsMode, sizeof (WifiMode));

  i.Read ((uint8_t *)&m_dataMode, sizeof (WifiMode));

}

void 

TxModeTag::Print (std::ostream &os) const

{

  os << "Rts=" << m_rtsMode << ", Data=" << m_dataMode;

}

} // namespace ns3

/***************************************************************

 *           WifiRemoteStation below.

 ***************************************************************/ 

namespace ns3 {

TypeId 

WifiRemoteStation::GetTypeId (void)

{

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

    .SetParent<Object> ()

    .AddTraceSource ("Ssrc", "The value of the ssrc counter: indicates the number of retransmissions of RTS.",

                     MakeTraceSourceAccessor (&WifiRemoteStation::m_ssrc))

    .AddTraceSource ("Slrc", "The value of the slrc counter: indicates the number of retransmissions of DATA.",

                     MakeTraceSourceAccessor (&WifiRemoteStation::m_slrc))

    ;

  return tid;

}

WifiRemoteStation::WifiRemoteStation ()

  : m_state (BRAND_NEW),

    m_ssrc (0),

    m_slrc (0),

    m_avgSlrcCoefficient(0.9),

{}

WifiRemoteStation::~WifiRemoteStation ()

{}

bool

WifiRemoteStation::IsBrandNew (void) const

{

  return m_state == BRAND_NEW;

}

bool 

WifiRemoteStation::IsAssociated (void) const

{

  return m_state == GOT_ASSOC_TX_OK;

}

bool 

WifiRemoteStation::IsWaitAssocTxOk (void) const

{

  return m_state == WAIT_ASSOC_TX_OK;

}

void 

WifiRemoteStation::RecordWaitAssocTxOk (void)

{

  m_state = WAIT_ASSOC_TX_OK;

}

void 

WifiRemoteStation::RecordGotAssocTxOk (void)

{

  m_state = GOT_ASSOC_TX_OK;

}

void 

WifiRemoteStation::RecordGotAssocTxFailed (void)

{

  m_state = DISASSOC;

}

void 

WifiRemoteStation::RecordDisassociated (void)

{

  m_state = DISASSOC;

}

void 

WifiRemoteStation::Reset (void)

{

  m_modes.clear ();

  AddSupportedMode (GetManager ()->GetDefaultMode ());

}

void