/* -*-  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>

 */

// Implementation for ns3 Application base class.

// George F. Riley, Georgia Tech, Fall 2006

#include "application.h"

#include "node.h"

#include "node-reference.h"

#include "ns3/nstime.h"

#include "ns3/random-variable.h"

#include "ns3/simulator.h"

using namespace std;

namespace ns3 {

// Application Methods

// \brief Application Constructor

  Application::Application(const Node& n) 

    : m_node (0),

      m_start(false), m_stop(false)

{

  SetNode(n);

}

Application::Application(const Application& o)

      m_start(false), m_stop(false)

{ // Copy constructor

  if (o.GetNode())m_node = new NodeReference(*o.GetNode());

  // Copy the start and stop random variables if they exist

  if (o.m_startVar) m_startVar = o.m_startVar->Copy();

  if (o.m_stopVar)  m_stopVar  = o.m_stopVar->Copy();

  if (o.m_start)    ScheduleStart();

  if (o.m_stop)     ScheduleStop();

}

// \brief Application Destructor

Application::~Application()

{

  delete m_node;

  // Cancel the start/stop events if scheduled

  if (m_start) Simulator::Cancel(m_startEvent);

  if (m_stop)  Simulator::Cancel(m_stopEvent);

  // Delete the random variablse

  delete m_startVar;

  delete m_stopVar;

}

Application& Application::operator=(const Application& rhs)

{

  if (this == &rhs) return *this; // Self assignment

  delete m_node;

  if (rhs.GetNode())m_node = new NodeReference(*rhs.GetNode());

  delete m_startVar;

  if (rhs.m_startVar) m_startVar = rhs.m_startVar->Copy();

  delete m_stopVar;

  if (rhs.m_stopVar) m_stopVar = rhs.m_stopVar->Copy();

  m_start = false;

  if (rhs.m_start) ScheduleStart();

  if (rhs.m_stop)  ScheduleStop();

  return *this;

}

// \brief Specify application start time

// The virtual method STartApp will be called at the time

// specified by startTime.

// \param Time to start application (absolute time, from start of simulation)

void Application::Start(const Time& startTime)

{

  delete m_startVar;

  m_startVar = new ConstantVariable(startTime.GetSeconds());

  ScheduleStart();

}

void Application::Start(const RandomVariable& startVar)

{ // Start at random time

  delete m_startVar;

  m_startVar = startVar.Copy();

  ScheduleStart();

}

// \brief Specify application stop time

// The virtual method StopApp will be called at the time

// specified by stopTime.

// \param Time to stop application (absolute time, from start of simulation)

void Application::Stop(const Time& stopTime)

{

  delete m_stopVar;

  m_stopVar = new ConstantVariable(stopTime.GetSeconds());

  ScheduleStop();

}

void Application::Stop(const RandomVariable& stopVar)

{ // Stop at random time

  delete m_stopVar;

  m_stopVar = stopVar.Copy();

  ScheduleStop();

}

// \brief Assign this application to a given node

// Called by the application manager capability when adding

// an application to a node.

void Application::SetNode(const Node& n)

{

  delete m_node;

  m_node = new NodeReference(n);

}

Node* Application::GetNode() const

{

  return m_node->GetNode();

}

// Protected methods

// StartApp and StopApp will likely be overridden by application subclasses

void Application::StartApplication()

{ // Provide null functionality in case subclass is not interested

}

void Application::StopApplication()

{ // Provide null functionality in case subclass is not interested

}

// Private helpers

void Application::ScheduleStart()

{

  m_startEvent = Simulator::Schedule(Seconds(m_startVar->GetValue()) -

                                     Simulator::Now(),

                                     &Application::StartApplication, this);

  m_start = true;

}

void Application::ScheduleStop()

{

  m_stopEvent = Simulator::Schedule(Seconds(m_stopVar->GetValue()) -

                                     Simulator::Now(),

                                     &Application::StopApplication, this);

  m_stop = true;

}

} //namespace ns3