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

/*

 * 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

 *

 * Authors: Joe Kopena <tjkopena@cs.drexel.edu>

 *

 * These applications are used in the WiFi Distance Test experiment,

 * described and implemented in test02.cc.  That file should be in the

 * same place as this file.  The applications have two very simple

 * jobs, they just generate and receive packets.  We could use the

 * standard Application classes included in the NS-3 distribution.

 * These have been written just to change the behavior a little, and

 * provide more examples.

 *

 */

#include <ostream>

#include "ns3/core-module.h"

#include "ns3/network-module.h"

#include "ns3/stats-module.h"

#include "wifi-example-apps.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("WiFiDistanceApps");

TypeId

Sender::GetTypeId(void)

{

  static TypeId tid = TypeId ("Sender")

    .SetParent<Application> ()

    .AddConstructor<Sender> ()

    .AddAttribute ("PacketSize", "The size of packets transmitted.",

                   UintegerValue(64),

                   MakeUintegerAccessor(&Sender::m_pktSize),

                   MakeUintegerChecker<uint32_t>(1))

    .AddAttribute("Destination", "Target host address.",

                  Ipv4AddressValue("255.255.255.255"),

                  MakeIpv4AddressAccessor(&Sender::m_destAddr),

                  MakeIpv4AddressChecker())

    .AddAttribute("Port", "Destination app port.",

                  UintegerValue(1603),

                  MakeUintegerAccessor(&Sender::m_destPort),

                  MakeUintegerChecker<uint32_t>())

    .AddAttribute("NumPackets", "Total number of packets to send.",

                  UintegerValue(30),

                  MakeUintegerAccessor(&Sender::m_numPkts),

                  MakeUintegerChecker<uint32_t>(1))

    .AddAttribute ("Interval", "Delay between transmissions.",

                   RandomVariableValue(ConstantVariable(0.5)),

                   MakeRandomVariableAccessor(&Sender::m_interval),

                   MakeRandomVariableChecker())

    .AddTraceSource ("Tx", "A new packet is created and is sent",

                     MakeTraceSourceAccessor (&Sender::m_txTrace))

    ;

  return tid;

}

Sender::Sender()

{

  NS_LOG_FUNCTION_NOARGS ();

  m_socket = 0;

}

Sender::~Sender()

{

  NS_LOG_FUNCTION_NOARGS ();

}

void

Sender::DoDispose (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_socket = 0;

  // chain up

  Application::DoDispose ();

}

void Sender::StartApplication()

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_socket == 0) {

      Ptr<SocketFactory> socketFactory = GetNode()->GetObject<SocketFactory>

        (UdpSocketFactory::GetTypeId());

      m_socket = socketFactory->CreateSocket ();

      m_socket->Bind ();

  }

  m_count = 0;

  Simulator::Cancel(m_sendEvent);

  m_sendEvent = Simulator::ScheduleNow(&Sender::SendPacket, this);

  // end Sender::StartApplication

}

void Sender::StopApplication()

{

  NS_LOG_FUNCTION_NOARGS ();

  Simulator::Cancel(m_sendEvent);

  // end Sender::StopApplication

}

void Sender::SendPacket()

{

  // NS_LOG_FUNCTION_NOARGS ();

  NS_LOG_INFO("Sending packet at " << Simulator::Now() << " to " <<

              m_destAddr);

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

  TimestampTag timestamp;

  timestamp.SetTimestamp(Simulator::Now());

  packet->AddByteTag (timestamp);

  // Could connect the socket since the address never changes; using SendTo

  // here simply because all of the standard apps do not.

  m_socket->SendTo(packet, 0, InetSocketAddress(m_destAddr, m_destPort));

  // Report the event to the trace.

  m_txTrace(packet);

  if (++m_count < m_numPkts) {

    m_sendEvent = Simulator::Schedule(Seconds(m_interval.GetValue()),

                                      &Sender::SendPacket, this);

  }

  // end Sender::SendPacket

}

//----------------------------------------------------------------------

//-- Receiver

//------------------------------------------------------

TypeId

Receiver::GetTypeId(void)

{

  static TypeId tid = TypeId ("Receiver")

    .SetParent<Application> ()

    .AddConstructor<Receiver> ()

    .AddAttribute("Port", "Listening port.",

                  UintegerValue(1603),

                  MakeUintegerAccessor(&Receiver::m_port),

                  MakeUintegerChecker<uint32_t>())

    ;

  return tid;

}

Receiver::Receiver() :

  m_calc(0),

  m_delay(0)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_socket = 0;

}

Receiver::~Receiver()

{

  NS_LOG_FUNCTION_NOARGS ();

}

void

Receiver::DoDispose (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  m_socket = 0;

  // chain up

  Application::DoDispose ();

}

void

Receiver::StartApplication()

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_socket == 0) {

      Ptr<SocketFactory> socketFactory = GetNode()->GetObject<SocketFactory>

        (UdpSocketFactory::GetTypeId());

      m_socket = socketFactory->CreateSocket();

      InetSocketAddress local = 

        InetSocketAddress(Ipv4Address::GetAny(), m_port);

      m_socket->Bind(local);

  }

  m_socket->SetRecvCallback(MakeCallback(&Receiver::Receive, this));

  // end Receiver::StartApplication

}

void

Receiver::StopApplication()

{

  NS_LOG_FUNCTION_NOARGS ();

  if (m_socket != 0) {

      m_socket->SetRecvCallback(MakeNullCallback<void, Ptr<Socket> > ());

  }

  // end Receiver::StopApplication

}

void

Receiver::SetCounter(Ptr<CounterCalculator<> > calc)

{

  m_calc = calc;

  // end Receiver::SetCounter

}

void

Receiver::SetDelayTracker(Ptr<TimeMinMaxAvgTotalCalculator> delay)

{

  m_delay = delay;

  // end Receiver::SetDelayTracker

}

void

Receiver::Receive(Ptr<Socket> socket)

{

  // NS_LOG_FUNCTION (this << socket << packet << from);

  Ptr<Packet> packet;

  Address from;

  while (packet = socket->RecvFrom(from)) {

    if (InetSocketAddress::IsMatchingType (from)) {

      InetSocketAddress address = InetSocketAddress::ConvertFrom (from);

      NS_LOG_INFO ("Received " << packet->GetSize() << " bytes from " << 

                   address.GetIpv4());

    }

    TimestampTag timestamp;

    // Should never not be found since the sender is adding it, but

    // you never know.

    if (packet->FindFirstMatchingByteTag(timestamp)) {

      Time tx = timestamp.GetTimestamp();

      if (m_delay != 0) {

        m_delay->Update(Simulator::Now() - tx);

      }

    }

    if (m_calc != 0) {

      m_calc->Update();

    }

    // end receiving packets

  }

  // end Receiver::Receive

}

//----------------------------------------------------------------------

//-- TimestampTag

//------------------------------------------------------

TypeId 

TimestampTag::GetTypeId(void)

{

  static TypeId tid = TypeId ("TimestampTag")

    .SetParent<Tag> ()

    .AddConstructor<TimestampTag> ()

    .AddAttribute ("Timestamp",

                   "Some momentous point in time!",

                   EmptyAttributeValue(),

                   MakeTimeAccessor(&TimestampTag::GetTimestamp),

                   MakeTimeChecker())

    ;

  return tid;

}

TypeId 

TimestampTag::GetInstanceTypeId(void) const

{

  return GetTypeId ();

}

uint32_t 

TimestampTag::GetSerializedSize (void) const

{

  return 8;

}

void 

TimestampTag::Serialize (TagBuffer i) const

{

  int64_t t = m_timestamp.GetNanoSeconds();

  i.Write((const uint8_t *)&t, 8);

}

void 

TimestampTag::Deserialize (TagBuffer i)

{

  int64_t t;

  i.Read((uint8_t *)&t, 8);

  m_timestamp = NanoSeconds(t);

}

void

TimestampTag::SetTimestamp(Time time)

{

  m_timestamp = time;

}

Time

TimestampTag::GetTimestamp(void) const

{

  return m_timestamp;

}

void 

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

{

  os << "t=" << m_timestamp;

}