/*

 * Copyright (c) 2009 CTTC

 *

 * 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: Nicola Baldo <nbaldo@cttc.es>

 */

#include <ns3/waveform-generator.h>

#include <ns3/object-factory.h>

#include <ns3/log.h>

#include <math.h>

#include <ns3/simulator.h>

#include <ns3/trace-source-accessor.h>

#include <ns3/packet-burst.h>

#include <ns3/callback.h>

#include "half-duplex-ideal-phy.h"

#include "spectrum-error-model.h"

NS_LOG_COMPONENT_DEFINE ("HalfDuplexIdealPhy");

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (HalfDuplexIdealPhy);

HalfDuplexIdealPhy::HalfDuplexIdealPhy ()

  : m_mobility (0),

    m_netDevice (0),

    m_channel (0),

    m_txPsd (0),

    m_state (IDLE)

{

  m_interference.SetErrorModel (CreateObject<ShannonSpectrumErrorModel> ());

}

HalfDuplexIdealPhy::~HalfDuplexIdealPhy ()

{

}

void

HalfDuplexIdealPhy::DoDispose ()

{

  NS_LOG_FUNCTION (this);

  m_mobility = 0;

  m_netDevice = 0;

  m_channel = 0;

  m_txPsd = 0;

  m_rxPsd = 0;

  m_txPacket = 0;

  m_rxPacket = 0;

  m_phyMacTxEndCallback      = MakeNullCallback< void, Ptr<const Packet> > ();

  m_phyMacRxStartCallback    = MakeNullCallback< void > ();

  m_phyMacRxEndErrorCallback = MakeNullCallback< void > ();

  m_phyMacRxEndOkCallback    = MakeNullCallback< void, Ptr<Packet> >  ();

  SpectrumPhy::DoDispose ();

}

std::ostream& operator<< (std::ostream& os, HalfDuplexIdealPhy::State s)

{

  switch (s)

    {

    case HalfDuplexIdealPhy::IDLE:

      os << "IDLE";

      break;

    case HalfDuplexIdealPhy::RX:

      os << "RX";

      break;

    case HalfDuplexIdealPhy::TX:

      os << "TX";

      break;

    default:

      os << "UNKNOWN";

      break;

    }

  return os;

}

TypeId

HalfDuplexIdealPhy::GetTypeId (void)

{

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

    .SetParent<SpectrumPhy> ()

    .AddConstructor<HalfDuplexIdealPhy> ()

    .AddAttribute ("Rate",

                   "The PHY rate used by this device",

                   DataRateValue (DataRate ("1Mbps")),

                   MakeDataRateAccessor (&HalfDuplexIdealPhy::SetRate,

                                         &HalfDuplexIdealPhy::GetRate),

                   MakeDataRateChecker ())

    .AddTraceSource ("TxStart",

                     "Trace fired when a new transmission is started",

                     MakeTraceSourceAccessor (&HalfDuplexIdealPhy::m_phyTxStartTrace))

    .AddTraceSource ("TxEnd",

                     "Trace fired when a previosuly started transmission is finished",

                     MakeTraceSourceAccessor (&HalfDuplexIdealPhy::m_phyTxEndTrace))

    .AddTraceSource ("RxStart",

                     "Trace fired when the start of a signal is detected",

                     MakeTraceSourceAccessor (&HalfDuplexIdealPhy::m_phyRxStartTrace))

    .AddTraceSource ("RxAbort",

                     "Trace fired when a previously started RX is aborted before time",

                     MakeTraceSourceAccessor (&HalfDuplexIdealPhy::m_phyRxAbortTrace))

    .AddTraceSource ("RxEndOk",

                     "Trace fired when a previosuly started RX terminates successfully",

                     MakeTraceSourceAccessor (&HalfDuplexIdealPhy::m_phyRxEndOkTrace))

    .AddTraceSource ("RxEndError",

                     "Trace fired when a previosuly started RX terminates with an error (packet is corrupted)",

                     MakeTraceSourceAccessor (&HalfDuplexIdealPhy::m_phyRxEndErrorTrace))

  ;

  return tid;

}

Ptr<Object>

HalfDuplexIdealPhy::GetDevice ()

{

  NS_LOG_FUNCTION (this);

  return m_netDevice;

}

Ptr<Object>

HalfDuplexIdealPhy::GetMobility ()

{

  NS_LOG_FUNCTION (this);

  return m_mobility;

}

void

HalfDuplexIdealPhy::SetDevice (Ptr<Object> d)

{

  NS_LOG_FUNCTION (this << d);

  m_netDevice = d;

}

void

HalfDuplexIdealPhy::SetMobility (Ptr<Object> m)

{

  NS_LOG_FUNCTION (this << m);

  m_mobility = m;

}

void

HalfDuplexIdealPhy::SetChannel (Ptr<SpectrumChannel> c)

{

  NS_LOG_FUNCTION (this << c);

  m_channel = c;

}

Ptr<const SpectrumModel>

HalfDuplexIdealPhy::GetRxSpectrumModel () const

{

  if (m_txPsd)

    {

      return m_txPsd->GetSpectrumModel ();

    }

  else

    {

      return 0;

    }

}

SpectrumType

HalfDuplexIdealPhy::GetSpectrumType ()

{

  NS_LOG_FUNCTION (this);

  static SpectrumType st = SpectrumTypeFactory::Create ("IdealOfdm");

  return st;

}

void

HalfDuplexIdealPhy::SetTxPowerSpectralDensity (Ptr<SpectrumValue> txPsd)

{

  NS_LOG_FUNCTION (this << txPsd);

  NS_ASSERT (txPsd);

  m_txPsd = txPsd;

  NS_LOG_INFO ( *txPsd << *m_txPsd);

}

void

HalfDuplexIdealPhy::SetNoisePowerSpectralDensity (Ptr<const SpectrumValue> noisePsd)

{

  NS_LOG_FUNCTION (this << noisePsd);

  NS_ASSERT (noisePsd);

  m_interference.SetNoisePowerSpectralDensity (noisePsd);

}

void

HalfDuplexIdealPhy::SetRate (DataRate rate)

{

  NS_LOG_FUNCTION (this << rate);

  m_rate = rate;

}

DataRate

HalfDuplexIdealPhy::GetRate () const

{

  NS_LOG_FUNCTION (this);

  return m_rate;

}

void

HalfDuplexIdealPhy::SetGenericPhyTxEndCallback (GenericPhyTxEndCallback c)

{

  NS_LOG_FUNCTION (this);

  m_phyMacTxEndCallback = c;

}

void

HalfDuplexIdealPhy::SetGenericPhyRxStartCallback (GenericPhyRxStartCallback c)

{

  NS_LOG_FUNCTION (this);

  m_phyMacRxStartCallback = c;

}

void

HalfDuplexIdealPhy::SetGenericPhyRxEndErrorCallback (GenericPhyRxEndErrorCallback c)

{

  NS_LOG_FUNCTION (this);

  m_phyMacRxEndErrorCallback = c;

}

void

HalfDuplexIdealPhy::SetGenericPhyRxEndOkCallback (GenericPhyRxEndOkCallback c)

{

  NS_LOG_FUNCTION (this);

  m_phyMacRxEndOkCallback = c;

}

void

HalfDuplexIdealPhy::ChangeState (State newState)

{

  NS_LOG_LOGIC (this << " state: " << m_state << " -> " << newState);

  m_state = newState;

}

bool

HalfDuplexIdealPhy::StartTx (Ptr<Packet> p)

{

  NS_LOG_FUNCTION (this << p);

  NS_LOG_LOGIC (this << "state: " << m_state);

  m_phyTxStartTrace (p);

  switch (m_state)

    {

    case RX:

      AbortRx ();

    // fall through

    case IDLE:

      {

        m_txPacket = p;

        ChangeState (TX);

        double txTimeSeconds = m_rate.CalculateTxTime (p->GetSize ());

        Ptr<PacketBurst> pb = Create<PacketBurst> ();

        pb->AddPacket (p);

        m_channel->StartTx (pb, m_txPsd, GetSpectrumType (), Seconds (txTimeSeconds), GetObject<SpectrumPhy> ());

        Simulator::Schedule (Seconds (txTimeSeconds), &HalfDuplexIdealPhy::EndTx, this);

      }

      break;

    case TX:

      return true;

      break;

    }

  return false;

}

void

HalfDuplexIdealPhy::EndTx ()

{

  NS_LOG_FUNCTION (this);

  NS_LOG_LOGIC (this << "state: " << m_state);

  NS_ASSERT (m_state == TX);

  m_phyTxEndTrace (m_txPacket);

  if (!m_phyMacTxEndCallback.IsNull ())

    {

      m_phyMacTxEndCallback (m_txPacket);

    }

  m_txPacket = 0;

  ChangeState (IDLE);

}

void

HalfDuplexIdealPhy::StartRx (Ptr<PacketBurst> pb, Ptr <const SpectrumValue> rxPsd, SpectrumType st, Time duration)

{

  NS_LOG_FUNCTION (this << pb << rxPsd << st << duration);

  NS_LOG_LOGIC (this << "state: " << m_state);

  // interference will happen regardless of the state of the receiver

  m_interference.AddSignal (rxPsd, duration);

  // the device might start RX only if the signal is of a type understood by this device

  // this corresponds in real device to preamble detection

  if (st == GetSpectrumType ())

    {

      switch (m_state)

        {

        case TX:

          // the PHY will not notice this incoming signal

          break;

        case RX:

          // we should check if we should re-sync on a new incoming signal and discard the old one

          // (somebody calls this the "capture" effect)

          // criteria considered to do might include the following:

          //  1) signal strength (e.g., as returned by rxPsd.Norm ())

          //  2) how much time has passed since previous RX attempt started

          // if re-sync (capture) is done, then we should call AbortRx ()

          break;

        case IDLE:

          // preamble detection and synchronization is supposed to be always successful.

          NS_LOG_LOGIC (this << " receiving " << pb->GetNPackets () << "  packet(s)" );

          NS_ASSERT (pb->GetNPackets () == 1); // this PHY only supports a single packet per waveform

          Ptr<Packet> p = pb->GetPackets ().front ();

          m_phyRxStartTrace (p);

          m_rxPacket = p;

          m_rxPsd = rxPsd;

          ChangeState (RX);

          if (!m_phyMacRxStartCallback.IsNull ())

            {

              NS_LOG_LOGIC (this << " calling m_phyMacRxStartCallback");

              m_phyMacRxStartCallback ();

            }

          else

            {

              NS_LOG_LOGIC (this << " m_phyMacRxStartCallback is NULL");

            }

          m_interference.StartRx (p, rxPsd);

          NS_LOG_LOGIC (this << " scheduling EndRx with delay " << duration);

          m_endRxEventId = Simulator::Schedule (duration, &HalfDuplexIdealPhy::EndRx, this);

          break;

        }

    }

  NS_LOG_LOGIC (this << "state: " << m_state);

}

void

HalfDuplexIdealPhy::AbortRx ()

{

  NS_LOG_FUNCTION (this);

  NS_LOG_LOGIC (this << "state: " << m_state);

  NS_ASSERT (m_state == RX);

  m_phyRxAbortTrace (m_rxPacket);

  m_endRxEventId.Cancel ();

  m_rxPacket = 0;

  ChangeState (IDLE);

}

void

HalfDuplexIdealPhy::EndRx ()

{

  NS_LOG_FUNCTION (this);

  NS_LOG_LOGIC (this << "state: " << m_state);

  NS_ASSERT (m_state == RX);

  bool rxOk = m_interference.EndRx ();

  if (rxOk)

    {

      m_phyRxEndOkTrace (m_rxPacket);

      if (!m_phyMacRxEndOkCallback.IsNull ())

        {

          NS_LOG_LOGIC (this << " calling m_phyMacRxEndOkCallback");

          m_phyMacRxEndOkCallback (m_rxPacket);

        }

      else

        {

          NS_LOG_LOGIC (this << " m_phyMacRxEndOkCallback is NULL");

        }

    }

  else

    {

      m_phyRxEndErrorTrace (m_rxPacket);

      if (!m_phyMacRxEndErrorCallback.IsNull ())

        {

          NS_LOG_LOGIC (this << " calling m_phyMacRxEndErrorCallback");

          m_phyMacRxEndErrorCallback ();

        }

      else

        {

          NS_LOG_LOGIC (this << " m_phyMacRxEndErrorCallback is NULL");

        }

    }

  ChangeState (IDLE);

  m_rxPacket = 0;

  m_rxPsd = 0;

}

} // namespace ns3