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

/*

 * Copyright (c) 2005,2006 INRIA

 * All rights reserved.

 *

 * 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

 *

 */

#include <iostream>

#include <cassert>

#include "ns3/debug.h"

#include "ns3/queue.h"

#include "ns3/simulator.h"

#include "ns3/composite-trace-resolver.h"

#include "p2p-net-device.h"

#include "p2p-channel.h"

NS_DEBUG_COMPONENT_DEFINE ("PointToPointNetDevice");

namespace ns3 {

: 

  m_txMachineState (READY),

  m_tInterframeGap (Seconds(0)),

  m_channel (0), 

  m_queue (0),

  m_rxTrace ()

{

  NS_DEBUG ("PointToPointNetDevice::PointToPointNetDevice (" << node << ")");

  // BUGBUG FIXME

  //

  // You _must_ support broadcast to get any sort of packet from the ARP layer.

  EnableBroadcast (MacAddress ("ff:ff:ff:ff:ff:ff"));

  EnableMulticast();

  EnablePointToPoint();

}

PointToPointNetDevice::~PointToPointNetDevice()

{

  NS_DEBUG ("PointToPointNetDevice::~PointToPointNetDevice ()");

  m_queue = 0;

}

//

// Copy constructor for PointToPointNetDevice.

//

// We use the underlying NetDevice copy constructor to get the base class

// copied.  These just remain as is (e.g. you get the same name, the same

// MAC address).  If you need to fix them up, YOU, the copier need to do 

// that.

// 

// The things we need to be careful of are the channel, the queue and the

// trace callback.  If the channel pointer is non-zero, we copy the pointer 

// and add a reference.  If the queue is non-zero, we copy it using the queue

// assignment operator.  We don't mess with the trace -- we just reset it.

// We're assuming that the tracing will be set up after the topology creation

// phase and this won't actually matter.

//

PointToPointNetDevice::PointToPointNetDevice (const PointToPointNetDevice& nd)

: 

  NetDevice(nd), 

  m_txMachineState(READY),

  m_bps (nd.m_bps),

  m_tInterframeGap (nd.m_tInterframeGap),

  m_channel(nd.m_channel), 

  m_queue(0),

  m_rxTrace ()

{

  NS_DEBUG ("PointToPointNetDevice::PointToPointNetDevice (" << &nd << ")");

  if (nd.m_queue)

    {

      m_queue = nd.m_queue;

    }

}

void PointToPointNetDevice::DoDispose()

{

  m_channel = 0;

  NetDevice::DoDispose ();

}

//

// Assignment operator for PointToPointNetDevice.

//

//

{

  NS_DEBUG ("PointToPointNetDevice::operator= (" << &nd << ")");

  return *this;

}

  void 

{

  m_bps = bps;

}

  void 

{

  m_tInterframeGap = t;

}

  bool

PointToPointNetDevice::SendTo (Packet& p, const MacAddress& dest)

{

  NS_DEBUG ("PointToPointNetDevice::SendTo (" << &p << ", " << &dest << ")");

  NS_DEBUG ("PointToPointNetDevice::SendTo (): UID is " << p.GetUid () << ")");

  NS_ASSERT (IsLinkUp ());

//

// This class simulates a point to point device.  In the case of a serial

// link, this means that we're simulating something like a UART.  This is

// not a requirement for a point-to-point link, but it's a typical model for

// the device.  

//

//

    if (m_txMachineState == READY) 

      {

        return TransmitStart (p);

      }

}

  bool

PointToPointNetDevice::TransmitStart (Packet &p)

{

  NS_DEBUG ("PointToPointNetDevice::TransmitStart (" << &p << ")");

  NS_DEBUG (

    "PointToPointNetDevice::TransmitStart (): UID is " << p.GetUid () << ")");

//

// This function is called to start the process of transmitting a packet.

// We need to tell the channel that we've started wiggling the wire and

//

  NS_ASSERT_MSG(m_txMachineState == READY, "Must be READY to transmit");

  m_txMachineState = BUSY;

  NS_DEBUG ("PointToPointNetDevice::TransmitStart (): " <<

    "Schedule TransmitCompleteEvent in " << 

                       this);

}

  void

{

  NS_DEBUG ("PointToPointNetDevice::TransmitCompleteEvent ()");

//

// This function is called to finish the  process of transmitting a packet.

// We need to tell the channel that we've stopped wiggling the wire and

// schedule an event that will be executed when it's time to re-enable

// the transmitter after the interframe gap.

//

  NS_ASSERT_MSG(m_txMachineState == BUSY, "Must be BUSY if transmitting");

  Packet p;

}

TraceResolver *

PointToPointNetDevice::DoCreateTraceResolver (TraceContext const &context)

{

  CompositeTraceResolver *resolver = new CompositeTraceResolver (context);

  resolver->Add ("queue", 

                 MakeCallback (&Queue::CreateTraceResolver, PeekPointer (m_queue)),

                 PointToPointNetDevice::QUEUE);

  resolver->Add ("rx",

                 m_rxTrace,

                 PointToPointNetDevice::RX);

  return resolver;

}

bool

PointToPointNetDevice::Attach (Ptr<PointToPointChannel> ch)

{

  NS_DEBUG ("PointToPointNetDevice::Attach (" << &ch << ")");

  m_channel = ch;

  m_channel->Attach(this);

  m_bps = m_channel->GetDataRate ();

  m_tInterframeGap = m_channel->GetDelay ();

  /* 

   * For now, this device is up whenever a channel is attached to it.

   * In fact, it should become up only when the second device

   * is attached to the channel. So, there should be a way for

   * a PointToPointChannel to notify both of its attached devices

   * that the channel is 'complete', hence that the devices are

   * up, hence that they can call NotifyLinkUp. 

   */

  NotifyLinkUp ();

  return true;

}

void

PointToPointNetDevice::AddQueue (Ptr<Queue> q)

{

  NS_DEBUG ("PointToPointNetDevice::AddQueue (" << q << ")");

  m_queue = q;

}

void

PointToPointNetDevice::Receive (Packet& p)

{

  // ignore return value for now.

  NS_DEBUG ("PointToPointNetDevice::Receive (" << &p << ")");

  m_rxTrace (p);

  ForwardUp (p);

}

Ptr<Queue>

PointToPointNetDevice::GetQueue(void) const 

{ 

    return m_queue;

}

Ptr<Channel>

PointToPointNetDevice::DoGetChannel(void) const 

{ 

    return m_channel;

}

bool 

PointToPointNetDevice::DoNeedsArp (void) const

{

  return false;

}

} // namespace ns3