/* -*-  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 <cmath>

#include "ns3/simulator.h"

#include "ns3/random-variable.h"

#include "ns3/pointer.h"

#include "random-waypoint-mobility-model.h"

#include "position-allocator.h"

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (RandomWaypointMobilityModel);

TypeId

RandomWaypointMobilityModel::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::RandomWaypointMobilityModel")

    .SetParent<MobilityModel> ()

    .SetGroupName ("Mobility")

    .AddConstructor<RandomWaypointMobilityModel> ()

    .AddAttribute ("Speed",

                   "A random variable used to pick the speed of a random waypoint model.",

                   RandomVariableValue (UniformVariable (0.3, 0.7)),

                   MakeRandomVariableAccessor (&RandomWaypointMobilityModel::m_speed),

                   MakeRandomVariableChecker ())

    .AddAttribute ("Pause",

                   "A random variable used to pick the pause of a random waypoint model.",

                   RandomVariableValue (ConstantVariable (2.0)),

                   MakeRandomVariableAccessor (&RandomWaypointMobilityModel::m_pause),

                   MakeRandomVariableChecker ())

    .AddAttribute ("Position",

                   "The position model used to pick a destination point.",

                   PointerValue (),

                   MakePointerAccessor (&RandomWaypointMobilityModel::m_position),

                   MakePointerChecker<PositionAllocator> ());

  return tid;

}

RandomWaypointMobilityModel::RandomWaypointMobilityModel ()

{

  Simulator::ScheduleNow (&RandomWaypointMobilityModel::Start, this);

}

void

RandomWaypointMobilityModel::BeginWalk (void)

{

  Vector m_current = m_helper.GetCurrentPosition ();

  Vector destination = m_position->GetNext ();

  double speed = m_speed.GetValue ();

  double dx = (destination.x - m_current.x);

  double dy = (destination.y - m_current.y);

  double dz = (destination.z - m_current.z);

  double k = speed / std::sqrt (dx*dx + dy*dy + dz*dz);

  m_helper.Reset (Vector (k*dx, k*dy, k*dz));

  Time travelDelay = Seconds (CalculateDistance (destination, m_current) / speed);

  m_event = Simulator::Schedule (travelDelay,

				 &RandomWaypointMobilityModel::Start, this);

  NotifyCourseChange ();

}

void

RandomWaypointMobilityModel::Start (void)

{

  Time pause = Seconds (m_pause.GetValue ());

  m_helper.Pause ();

  NotifyCourseChange ();

  m_event = Simulator::Schedule (pause, &RandomWaypointMobilityModel::BeginWalk, this);

}

Vector

RandomWaypointMobilityModel::DoGetPosition (void) const

{

  return m_helper.GetCurrentPosition ();

}

void 

RandomWaypointMobilityModel::DoSetPosition (const Vector &position)

{

  m_helper.InitializePosition (position);

  Simulator::Remove (m_event);

  Simulator::ScheduleNow (&RandomWaypointMobilityModel::Start, this);

}

Vector

RandomWaypointMobilityModel::DoGetVelocity (void) const

{

  return m_helper.GetVelocity ();

}

} // namespace ns3