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

/*

 * Copyright (c) 2007 INRIA

 *

 * 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: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#include "timer.h"

#include "simulator.h"

#include "simulation-singleton.h"

#include "log.h"

Timer::Timer ()

  : m_flags (CHECK_ON_DESTROY),

    m_delay (FemtoSeconds (0)),

    m_event (),

    m_impl (0)

{

  NS_LOG_FUNCTION (this);

}

Timer::Timer (enum DestroyPolicy destroyPolicy)

  : m_flags (destroyPolicy),

    m_delay (FemtoSeconds (0)),

    m_event (),

    m_impl (0)

{

  NS_LOG_FUNCTION (this << destroyPolicy);

}

Timer::~Timer ()

{

  NS_LOG_FUNCTION (this);

  if (m_flags & CHECK_ON_DESTROY)

    {

      if (m_event.IsRunning ())

        {

          NS_FATAL_ERROR ("Event is still running while destroying.");

        }

    }

  else if (m_flags & CANCEL_ON_DESTROY)

    {

      m_event.Cancel ();

    }

  else if (m_flags & REMOVE_ON_DESTROY)

    {

      Simulator::Remove (m_event);

    }

  delete m_impl;

}

void

Timer::SetDelay (const Time &time)

{

  NS_LOG_FUNCTION (this << time);

  m_delay = time;

}

Time

Timer::GetDelay (void) const

{

  NS_LOG_FUNCTION (this);

  return m_delay;

}

Time

Timer::GetDelayLeft (void) const

{

  NS_LOG_FUNCTION (this);

  switch (GetState ())

    {

    case Timer::RUNNING:

      return Simulator::GetDelayLeft (m_event);

      break;

    case Timer::EXPIRED:

      return TimeStep (0);

      break;

    case Timer::SUSPENDED:

      return m_delayLeft;

      break;

    default:

      NS_ASSERT (false);

      return TimeStep (0);

      break;

    }

}

void

Timer::Cancel (void)

{

  NS_LOG_FUNCTION (this);

  Simulator::Cancel (m_event);

}

void

Timer::Remove (void)

{

  NS_LOG_FUNCTION (this);

  Simulator::Remove (m_event);

}

bool

Timer::IsExpired (void) const

{

  NS_LOG_FUNCTION (this);

  return !IsSuspended () && m_event.IsExpired ();

}

bool

Timer::IsRunning (void) const

{

  NS_LOG_FUNCTION (this);

  return !IsSuspended () && m_event.IsRunning ();

}

bool

Timer::IsSuspended (void) const

{

  NS_LOG_FUNCTION (this);

  return (m_flags & TIMER_SUSPENDED) == TIMER_SUSPENDED;

}

enum Timer::State

Timer::GetState (void) const

{

  NS_LOG_FUNCTION (this);

  if (IsRunning ())

    {

      return Timer::RUNNING;

    }

  else if (IsExpired ())

    {

      return Timer::EXPIRED;

    }

  else

    {

      NS_ASSERT (IsSuspended ());

      return Timer::SUSPENDED;

    }

}

void

Timer::Schedule (void)

{

  NS_LOG_FUNCTION (this);

  Schedule (m_delay);

}

void

Timer::Schedule (Time delay)

{

  NS_LOG_FUNCTION (this << delay);

  NS_ASSERT (m_impl != 0);

  if (m_event.IsRunning ())

    {

      NS_FATAL_ERROR ("Event is still running while re-scheduling.");

    }

  m_event = m_impl->Schedule (delay);

}

void

Timer::Suspend (void)

{

  NS_LOG_FUNCTION (this);

  NS_ASSERT (IsRunning ());

  m_delayLeft = Simulator::GetDelayLeft (m_event);

  Simulator::Remove (m_event);

  m_flags |= TIMER_SUSPENDED;

}

void

Timer::Resume (void)

{

  NS_LOG_FUNCTION (this);

  NS_ASSERT (m_flags & TIMER_SUSPENDED);

  m_event = m_impl->Schedule (m_delayLeft);

  m_flags &= ~TIMER_SUSPENDED;

}

} // namespace ns3