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

/*

 * Copyright (c) 2006 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 "ideal-mac-stations.h"

#include "ns3/assert.h"

#include <math.h>

#define noIDEAL_DEBUG 1

#ifdef IDEAL_DEBUG

#include <iostream>

#  define TRACE(x) \

std::cout << "IDEAL TRACE " << x << std::endl;

#else

#  define TRACE(x)

#endif

namespace ns3 {

IdealMacStations::IdealMacStations (WifiMode defaultTxMode)

  : MacStations (defaultTxMode)

{}

IdealMacStations::~IdealMacStations ()

{}

MacStation *

IdealMacStations::CreateStation (void)

{

  return new IdealMacStation (this);

}

double 

IdealMacStations::GetSnrThreshold (WifiMode mode) const

{

  for (Thresholds::const_iterator i = m_thresholds.begin (); i != m_thresholds.end (); i++) 

    {

      if (mode == i->second)

        {

          return i->first;

        }

    }

  NS_ASSERT (false);

  return 0.0;

}

void 

IdealMacStations::AddModeSnrThreshold (WifiMode mode, double snr)

{

  m_thresholds.push_back (std::make_pair (snr,mode));

}

IdealMacStation::IdealMacStation (IdealMacStations *stations)

  : m_stations (stations)

{}

IdealMacStation::~IdealMacStation ()

{}

void 

IdealMacStation::ReportRxOk (double rxSnr, WifiMode txMode)

{}

void 

IdealMacStation::ReportRtsFailed (void)

{}

void 

IdealMacStation::ReportDataFailed (void)

{}

void 

IdealMacStation::ReportRtsOk (double ctsSnr, WifiMode ctsMode, double rtsSnr)

{

  TRACE ("got cts for rts snr="<<rtsSnr);

  m_lastSnr = rtsSnr;

}

void 

IdealMacStation::ReportDataOk (double ackSnr, WifiMode ackMode, double dataSnr)

{

  TRACE ("got cts for rts snr="<<dataSnr);

  m_lastSnr = dataSnr;

}

WifiMode

IdealMacStation::GetDataMode (uint32_t size)

{

  // We search within the Supported rate set the mode with the 

  // highest snr threshold possible which is smaller than m_lastSnr 

  // to ensure correct packet delivery.

  double maxThreshold = 0.0;

  WifiMode maxMode = m_stations->GetDefaultMode ();

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

    {

      WifiMode mode = GetSupportedMode (i);

      double threshold = m_stations->GetSnrThreshold (mode);

      if (threshold > maxThreshold && 

          threshold < m_lastSnr)

        {

          maxThreshold = threshold;

          maxMode = mode;

        }

    }

  return maxMode;

}

WifiMode

IdealMacStation::GetRtsMode (void)

{

  // We search within the Basic rate set the mode with the highest 

  // snr threshold possible which is smaller than m_lastSnr to 

  // ensure correct packet delivery.

  double maxThreshold = 0.0;

  WifiMode maxMode = m_stations->GetDefaultMode ();

  for (uint32_t i = 0; i < m_stations->GetNBasicModes (); i++)

    {

      WifiMode mode = m_stations->GetBasicMode (i);

      double threshold = m_stations->GetSnrThreshold (mode);

      if (threshold > maxThreshold && 

          threshold < m_lastSnr)

        {

          maxThreshold = threshold;

          maxMode = mode;

        }

    }

  return maxMode;

}

IdealMacStations *

IdealMacStation::GetStations (void) const

{

  return m_stations;

}

} // namespace ns3