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

//

// Copyright (c) 2006 Georgia Tech Research Corporation

//

// 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: George F. Riley<riley@ece.gatech.edu>

//

// ns3 - On/Off Data Source Application class

// George F. Riley, Georgia Tech, Spring 2007

// Adapted from ApplicationOnOff in GTNetS.

#include "ipv4-address.h"

#include "node.h"

#include "ns3/nstime.h"

#include "ns3/data-rate.h"

#include "onoff-application.h"

#include "ns3/random-variable.h"

#include "socket.h"

#include "ns3/simulator.h"

#include "udp.h"

using namespace std;

namespace ns3 {

// Defaults for rate/size

DataRate OnOffApplication::g_defaultRate = DataRate(500000);

uint32_t OnOffApplication::g_defaultSize = 512;

// Constructors

  OnOffApplication::OnOffApplication(Node * n, 

                                     const Ipv4Address  rip,   // Remote IP addr

                                     uint16_t       rport, // Remote port

                                     const  RandomVariable& ontime,

                                     const  RandomVariable& offtime,

                                     DataRate  rate,

                                     uint32_t size)

    :  Application(n), 

      m_socket(0),      // Socket allocated on Start

      m_peerIP(rip),

      m_peerPort(rport),

      m_connected(false),

      m_onTime(ontime.Copy()),

      m_offTime(offtime.Copy()),

      m_cbrRate(rate),

      m_pktSize(size), 

      m_residualBits(0),

      m_lastStartTime((HighPrecision)0),

      m_maxBytes(0xffffffff),

      m_totBytes(0),

      m_startStopScheduled(false),

      m_sendScheduled(false)

{

}

OnOffApplication::OnOffApplication(Node * n, const OnOffApplication& c)

  : Application(n), 

    m_socket(0),

    m_peerIP(c.m_peerIP),

    m_peerPort(c.m_peerPort),

    m_connected(c.m_connected),

    m_onTime(c.m_onTime->Copy()),

    m_offTime(c.m_offTime->Copy()),

    m_cbrRate(c.m_cbrRate),

    m_pktSize(c.m_pktSize),

    m_residualBits(c.m_residualBits),

    m_lastStartTime(c.m_lastStartTime),

    m_maxBytes(c.m_maxBytes),

    m_totBytes(c.m_totBytes),

    m_startStopScheduled(false),

    m_sendScheduled(false)

{

}

OnOffApplication::~OnOffApplication()

{

  Dispose ();

}

void

OnOffApplication::Dispose (void)

{

  if (m_socket != 0)

    {

      m_socket->Unref ();

      m_socket = 0;

    }

  delete m_onTime;

  delete m_offTime;

  m_onTime = 0;

  m_offTime = 0;

  // chain up

  Application::Dispose ();

}

#ifdef REMOVE_THIS

// Handler Methods

void OnOffApplication::Handle(Event* e, Time_t t)

{

  AppOOEvent* ev = (AppOOEvent*)e;

  switch (ev->event) {

    case AppOOEvent::SEND_PKT :

      {

        SendPkt(false);         // Send the packet

        return;

      }

    case AppOOEvent::START_GEN :

      {

        DEBUG0((cout << "StartGen at " << Simulator::Now() << endl));

        lastStartTime = Simulator::Now();

        ScheduleNextTx();

        Time_t onInterval = onTime->Value();

        pendingOO->event = AppOOEvent::STOP_GEN;

         // Schedule the stop event

        Simulator::Schedule(pendingOO, onInterval, this);

        return;

      }

    case AppOOEvent::STOP_GEN :

      {

        DEBUG0((cout << "StopGen at " << Simulator::Now() << endl));

        if (totBytes < maxBytes)

          { // Only schedule if not execeeded maxBytes

            Time_t offInterval = offTime->Value();

            pendingOO->event = AppOOEvent::START_GEN;

            // Schedule the start event

            Simulator::Schedule(pendingOO, offInterval, this);

          }

        if (pendingEvent)

          {

            // Calculate residual bits since last packet sent

            residualBits += (uint32_t)(cbrRate*(Simulator::Now()-lastStartTime));

            Simulator::Cancel(pendingEvent);

            delete pendingEvent;

            pendingEvent = 0;

          }

        return;

      }

  }

  Application::Handle(e, t);  // May be application event

}

#endif

// Application Methods

void OnOffApplication::StartApplication()    // Called at time specified by Start

{

  // Create the socket if not already

  if (!m_socket)

    { // Create the socket using the specified layer 4 protocol

#ifdef NOTYET

      m_socket = PeekNode()->GetKernel()->CreateGenericSocket(*m_l4Proto);

      m_socket->Bind();  // Choose any available port local port

      m_socket->Connect(*m_peerIP, m_peerPort,

                        MakeCallback(&OnOffApplication::ConnectionSucceeded,

                                     this),

                        MakeCallback(&OnOffApplication::ConnectionFailed,

                                     this));

#endif

      Udp *udp = PeekNode ()->GetUdp ();

      m_socket = udp->CreateSocket ();

      udp->Unref ();

      m_socket->Connect (m_peerIP, m_peerPort);

    }

  StopApplication();                         // Insure no pending event

  // If we are not yet connected, there is nothing to do here

  // The ConnectionComplete upcall will start timers at that time

  //if (!m_connected) return;

  ScheduleStartEvent();

}

void OnOffApplication::StopApplication()     // Called at time specified by Stop

{

  if (m_startStopScheduled)

    { // Cancel the startStop event

      Simulator::Cancel(m_startStopEvent);

      m_startStopScheduled = false;

    }

  if (m_sendScheduled)

    { // Cancel the pending send packet event

      Simulator::Cancel(m_sendEvent);

      m_sendScheduled = false;

      // Calculate residual bits since last packet sent

      Time delta(Simulator::Now() - m_lastStartTime);

      m_residualBits += (uint32_t)(m_cbrRate.GetBitRate() * delta.GetSeconds());

    }

}

OnOffApplication* OnOffApplication::Copy() const

{

  return new OnOffApplication(*this);

}

// Event handlers

void OnOffApplication::StartSending()

{

  m_startStopScheduled = true;

  ScheduleNextTx();  // Schedule the send packet event

}

void OnOffApplication::StopSending()

{

  m_startStopScheduled = true;

  if (m_sendScheduled) Simulator::Cancel(m_sendEvent);

}

// Private helpers

void OnOffApplication::ScheduleNextTx()

{

  if (m_totBytes < m_maxBytes)

    {

      uint32_t bits = m_pktSize * 8 - m_residualBits;

      Time nextTime(Seconds (bits / 

        static_cast<double>(m_cbrRate.GetBitRate()))); // Time till next packet

      m_sendScheduled = true;

      m_sendEvent = Simulator::Schedule(nextTime, &OnOffApplication::SendPacket, this);

    }

  else

    { // All done, cancel any pending events

      StopApplication();

    }

}

void OnOffApplication::ScheduleStartEvent()

{  // Schedules the event to start sending data (switch to the "On" state)

  Time offInterval = Seconds(m_offTime->GetValue());

  m_startStopEvent = Simulator::Schedule(offInterval, &OnOffApplication::StartSending, this);

  m_startStopScheduled = true;

}

void OnOffApplication::ScheduleStopEvent()

{  // Schedules the event to stop sending data (switch to "Off" state)

  Time onInterval = Seconds(m_onTime->GetValue());

  Simulator::Schedule(onInterval, &OnOffApplication::StopSending, this);

  m_startStopScheduled = true;

}

void OnOffApplication::SendPacket()

{

  NS_ASSERT (m_sendScheduled);

  m_sendScheduled = false;

  m_socket->Send(0, m_pktSize);

#ifdef NOTYET

  m_socket->Send(0, m_pktSize); // Send the packet

#endif

  m_totBytes += m_pktSize;

  m_lastStartTime = Simulator::Now();

  m_residualBits = 0;

  ScheduleNextTx();

}

void OnOffApplication::ConnectionSucceeded(Socket*)

{

  m_connected = true;

  ScheduleStartEvent();

}

void OnOffApplication::ConnectionFailed(Socket*)

{

  cout << "OnOffApplication, Connection Failed" << endl;

}

} // Namespace ns3