/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/* 
 * Copyright (c) 2009 IITP RAS
 * 
 * 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: Kirill Andreev <andreev@iitp.ru>
 *          Pavel Boyko <boyko@iitp.ru>
 */

#include "ns3/mesh-wifi-interface-mac.h"
#include "ns3/mesh-wifi-beacon.h"
#include "ns3/log.h"
#include "ns3/wifi-phy.h"
#include "ns3/dcf-manager.h"
#include "ns3/mac-rx-middle.h"
#include "ns3/mac-low.h"
#include "ns3/dca-txop.h"
#include "ns3/mesh-wifi-mac-header.h"
#include "ns3/random-variable.h"
#include "ns3/simulator.h"

NS_LOG_COMPONENT_DEFINE ("MeshWifiInterfaceMac");

namespace ns3 {

NS_OBJECT_ENSURE_REGISTERED (MeshWifiInterfaceMac);

TypeId
MeshWifiInterfaceMac::GetTypeId ()
{
  static TypeId tid = TypeId ("ns3::MeshWifiInterfaceMac")
                      .SetParent<WifiMac> ()
                      .AddConstructor<MeshWifiInterfaceMac> ()
                      .AddAttribute ("BeaconInterval", "Beacon Interval",
                                     TimeValue (Seconds (1.0)),
                                     MakeTimeAccessor (&MeshWifiInterfaceMac::m_beaconInterval),
                                     MakeTimeChecker ()
                                    )
                      .AddAttribute ("RandomStart", "Window when beacon generating starts (uniform random) in seconds",
                                     TimeValue (Seconds (0.1)),
                                     MakeTimeAccessor (&MeshWifiInterfaceMac::m_randomStart),
                                     MakeTimeChecker ()
                                    )
                      .AddAttribute ("SoftwareDelay", "Window of uniformely distributed random software handling delay",
                                     TimeValue (MicroSeconds (500)),
                                     MakeTimeAccessor (&MeshWifiInterfaceMac::m_softwareDelay),
                                     MakeTimeChecker ()
                                    )
                      .AddAttribute ("BeaconGeneration", "Enable/Disable Beaconing.",
                                     BooleanValue (true),
                                     MakeBooleanAccessor (
                                       &MeshWifiInterfaceMac::SetBeaconGeneration,
                                       &MeshWifiInterfaceMac::GetBeaconGeneration
                                     ),
                                     MakeBooleanChecker ()
                                    );
  return tid;
}

MeshWifiInterfaceMac::MeshWifiInterfaceMac ()
{
  NS_LOG_FUNCTION (this);
  
  m_rxMiddle = new MacRxMiddle ();
  m_rxMiddle->SetForwardCallback (MakeCallback (&MeshWifiInterfaceMac::Receive, this));

  m_low = CreateObject<MacLow> ();
  m_low->SetRxCallback (MakeCallback (&MacRxMiddle::Receive, m_rxMiddle));

  m_dcfManager = new DcfManager ();
  m_dcfManager->SetupLowListener (m_low);

  m_beaconDca = CreateObject<DcaTxop> ();
  m_beaconDca->SetLow (m_low);
  m_beaconDca->SetMinCw (0);
  m_beaconDca->SetMaxCw (0);
  m_beaconDca->SetAifsn (1);
  m_beaconDca->SetManager (m_dcfManager);

  m_VO = CreateObject<DcaTxop> ();
  m_VO->SetLow (m_low);
  m_VO->SetMinCw (3);
  m_VO->SetMaxCw (7);
  m_VO->SetManager (m_dcfManager);

  m_BE = CreateObject<DcaTxop> ();
  m_BE->SetLow (m_low);
  m_BE->SetManager (m_dcfManager);
}

MeshWifiInterfaceMac::~MeshWifiInterfaceMac ()
{
  NS_LOG_FUNCTION (this);
}

//-----------------------------------------------------------------------------
// WifiMac inherited
//-----------------------------------------------------------------------------
void
MeshWifiInterfaceMac::SetSlot (Time slotTime)
{
  NS_LOG_FUNCTION (this << slotTime);
  m_dcfManager->SetSlot (slotTime);
  m_slot = slotTime;
}

void
MeshWifiInterfaceMac::SetSifs (Time sifs)
{
  NS_LOG_FUNCTION (this << sifs);
  m_dcfManager->SetSifs (sifs);
  m_sifs = sifs;
}
void
MeshWifiInterfaceMac::SetAckTimeout (Time ackTimeout)
{
  m_low->SetAckTimeout (ackTimeout);
}

void
MeshWifiInterfaceMac::SetCtsTimeout (Time ctsTimeout)
{
  m_low->SetCtsTimeout (ctsTimeout);
}

void
MeshWifiInterfaceMac::SetPifs (Time pifs)
{
  NS_LOG_FUNCTION (this << pifs);
  m_pifs = pifs;
}
void
MeshWifiInterfaceMac::SetEifsNoDifs (Time eifsNoDifs)
{
  NS_LOG_FUNCTION (this << eifsNoDifs);
  m_dcfManager->SetEifsNoDifs (eifsNoDifs);
  m_eifsNoDifs = eifsNoDifs;
}

Time
MeshWifiInterfaceMac::GetSlot () const
{
  return m_slot;
}

Time
MeshWifiInterfaceMac::GetSifs () const
{
  return m_sifs;
}

Time
MeshWifiInterfaceMac::GetEifsNoDifs () const
{
  return m_eifsNoDifs;
}

Time
MeshWifiInterfaceMac::GetAckTimeout () const
{
  return m_low->GetAckTimeout ();
}

Time
MeshWifiInterfaceMac::GetCtsTimeout () const
{
  return m_low->GetCtsTimeout ();
}

Time
MeshWifiInterfaceMac::GetPifs () const
{
  return m_low->GetPifs ();
}

void
MeshWifiInterfaceMac::SetWifiPhy (Ptr<WifiPhy> phy)
{
  NS_LOG_FUNCTION (this << phy);
  m_phy = phy;
  m_dcfManager->SetupPhyListener (phy);
  m_low->SetPhy (phy);
}

void
MeshWifiInterfaceMac::SetWifiRemoteStationManager (Ptr<WifiRemoteStationManager> stationManager)
{
  NS_LOG_FUNCTION (this << stationManager);
  m_stationManager = stationManager;
  m_BE->SetWifiRemoteStationManager (stationManager);
  m_VO->SetWifiRemoteStationManager (stationManager);
  m_beaconDca->SetWifiRemoteStationManager (stationManager);
  m_low->SetWifiRemoteStationManager (stationManager);
}

void
MeshWifiInterfaceMac::Enqueue (Ptr<const Packet> packet, Mac48Address to, Mac48Address from)
{
  NS_LOG_FUNCTION (this << packet << to << from);
  ForwardDown (packet, from, to);
}

void
MeshWifiInterfaceMac::Enqueue (Ptr<const Packet> packet, Mac48Address to)
{
  NS_LOG_FUNCTION (this << packet << to);
  ForwardDown (packet, m_low->GetAddress (), to);
}

bool
MeshWifiInterfaceMac::SupportsSendFrom () const
{
  return true;
}

void
MeshWifiInterfaceMac::SetForwardUpCallback (Callback<void,Ptr<Packet>, Mac48Address, Mac48Address> upCallback)
{
  NS_LOG_FUNCTION (this);
  m_upCallback = upCallback;
}

void
MeshWifiInterfaceMac::SetLinkUpCallback (Callback<void> linkUp)
{
  NS_LOG_FUNCTION (this);
  if (!linkUp.IsNull ())
    {
      linkUp ();
    }
}

void
MeshWifiInterfaceMac::SetLinkDownCallback (Callback<void> linkDown)
{
  NS_LOG_FUNCTION (this);
}

Mac48Address
MeshWifiInterfaceMac::GetAddress () const
{
  return m_address;
}
Mac48Address
MeshWifiInterfaceMac::GetBssid () const
{
  return m_address;
}

Ssid
MeshWifiInterfaceMac::GetSsid () const
{
  return m_MeshId;
}

void
MeshWifiInterfaceMac::SetAddress (Mac48Address address)
{
  NS_LOG_FUNCTION (address);
  m_low->SetAddress (address);
  m_address = address;
}

void
MeshWifiInterfaceMac::SetSsid (Ssid ssid)
{
  NS_LOG_FUNCTION (ssid);
  m_MeshId = ssid;
}

void
MeshWifiInterfaceMac::DoDispose ()
{
  NS_LOG_FUNCTION (this);
  delete m_rxMiddle;
  delete m_dcfManager;
  //Delete smart pointers:
  m_rxMiddle = 0;
  m_low = 0;
  m_dcfManager = 0;
  m_phy = 0;
  m_BE = 0;
  m_VO = 0;
  m_beaconSendEvent.Cancel ();
  m_beaconDca = 0;
  
  WifiMac::DoDispose ();
}

//-----------------------------------------------------------------------------
// Plugins
//-----------------------------------------------------------------------------
void 
MeshWifiInterfaceMac::InstallPlugin ( Ptr<MeshWifiInterfaceMacPlugin> plugin)
{
  plugin->SetParent (this);
  m_plugins.push_back (plugin);
}

//-----------------------------------------------------------------------------
// Forward frame up/down
//-----------------------------------------------------------------------------
void
MeshWifiInterfaceMac::ForwardUp (Ptr<Packet> packet, Mac48Address src, Mac48Address dst)
{
  NS_LOG_FUNCTION (this << packet << src);
  m_upCallback (packet, src, dst);
}

void
MeshWifiInterfaceMac::ForwardDown (Ptr<const Packet> const_packet, Mac48Address from, Mac48Address to)
{
  // copy packet to allow modifications
  Ptr<Packet> packet = const_packet->Copy ();
  
  WifiMacHeader hdr;
  hdr.SetTypeData ();
  hdr.SetAddr2 (GetAddress ());
  hdr.SetAddr3 (to);
  hdr.SetAddr4 (from);
  hdr.SetDsFrom ();
  hdr.SetDsTo ();
  
  // Address 1 is unknwon here. Routing plugin is responsible to correctly set it.
  hdr.SetAddr1 (Mac48Address ());
  
  // Filter packet through all installed plugins
  for (PluginList::const_iterator i = m_plugins.begin(); i != m_plugins.end(); ++i)
    {
      bool drop = ! ((*i)->UpdateOutcomingFrame(packet, hdr, from, to));
      if (drop) return; // plugin drops frame
    }
  
  // Assert that address1 is set. Assert will fail e.g. if there is no installed routing plugin.
  NS_ASSERT (hdr.GetAddr1() != Mac48Address() );
  
  // Queue frame
  WifiRemoteStation *destination = m_stationManager->Lookup (to);

  if (destination->IsBrandNew ())
    {
      // in adhoc mode, we assume that every destination
      // supports all the rates we support.
      for (uint32_t i = 0; i < m_phy->GetNModes (); i++)
        {
          destination->AddSupportedMode (m_phy->GetMode (i));
        }
      destination->RecordDisassociated ();
    }
  m_BE->Queue (packet, hdr);
}

SupportedRates
MeshWifiInterfaceMac::GetSupportedRates () const
{
  // set the set of supported rates and make sure that we indicate
  // the Basic Rate set in this set of supported rates.
  SupportedRates rates;
  for (uint32_t i = 0; i < m_phy->GetNModes (); i++)
    {
      WifiMode mode = m_phy->GetMode (i);
      rates.AddSupportedRate (mode.GetDataRate ());
    }
  // set the basic rates
  for (uint32_t j = 0; j < m_stationManager->GetNBasicModes (); j++)
    {
      WifiMode mode = m_stationManager->GetBasicMode (j);
      rates.SetBasicRate (mode.GetDataRate ());
    }
  return rates;
}

//-----------------------------------------------------------------------------
// Beacons
//-----------------------------------------------------------------------------
void
MeshWifiInterfaceMac::SetSoftwareDelay (Time delay)
{
  NS_ASSERT (delay < m_beaconInterval);
  m_softwareDelay = delay;
}

Time
MeshWifiInterfaceMac::GetSoftwareDelay ()
{
  return m_softwareDelay;
}

Time
MeshWifiInterfaceMac::CalcSwDelay ()
{
#if 0
  UniformVariable coefficient (0.0, m_softwareDelay.GetSeconds());
  
  // Be sure that frames don't change order due to different software delays
  Time delay = Seconds (coefficient.GetValue());
  if (delay.GetSeconds () + Simulator::Now().GetSeconds() < m_lastMgtFrame.GetSeconds())
    delay = Seconds (m_lastMgtFrame.GetSeconds() - Simulator::Now().GetSeconds());
  m_lastMgtFrame = Seconds (Simulator::Now().GetSeconds() + delay.GetSeconds());

  NS_ASSERT (delay.GetSeconds() >= 0);
  return delay;
#endif
  return MicroSeconds(0);
}

void
MeshWifiInterfaceMac::SetBeaconInterval (Time interval)
{
  NS_LOG_FUNCTION (this << interval);
  m_beaconInterval = interval;
  
  NS_ASSERT (m_beaconInterval > m_softwareDelay);
}

Time 
MeshWifiInterfaceMac::GetBeaconInterval () const
{
  return m_beaconInterval;
}

void
MeshWifiInterfaceMac::SetBeaconGeneration (bool enable)
{
  NS_LOG_FUNCTION (this << enable);
  if (enable)
    {
      // Now start sending beacons after some random delay (to avoid collisions)
      UniformVariable coefficient (0.0, m_randomStart.GetSeconds());
      Time randomStart = Seconds (coefficient.GetValue());
      
      m_beaconSendEvent = Simulator::Schedule (randomStart, &MeshWifiInterfaceMac::SendBeacon, this);
      m_tbtt = Simulator::Now() + randomStart;
    }
  else
    // stop sending beacons
    m_beaconSendEvent.Cancel ();
}

bool
MeshWifiInterfaceMac::GetBeaconGeneration () const
{
  return m_beaconSendEvent.IsRunning ();
}

Time
MeshWifiInterfaceMac::GetTbtt () const
{
  return m_tbtt;
}

void MeshWifiInterfaceMac::ShiftTbtt (Time shift)
{
  // User of ShiftTbtt () must take care don't shift it to the past
  NS_ASSERT (GetTbtt() + shift > Simulator::Now());
  
  m_tbtt += shift;
  // Shift scheduled event
  Simulator::Cancel (m_beaconSendEvent);
  m_beaconSendEvent = Simulator::Schedule (GetTbtt () - Simulator::Now(), &MeshWifiInterfaceMac::SendBeacon, this);
}

void 
MeshWifiInterfaceMac::ScheduleNextBeacon ()
{
  m_tbtt += GetBeaconInterval ();
  m_beaconSendEvent = Simulator::Schedule (GetBeaconInterval(), &MeshWifiInterfaceMac::SendBeacon, this);
}

void
MeshWifiInterfaceMac::SendBeacon ()
{
  NS_LOG_FUNCTION (this);
  NS_LOG_DEBUG (GetAddress() <<" is sending beacon");
  
  NS_ASSERT (! m_beaconSendEvent.IsRunning());
  NS_ASSERT (Simulator::Now().GetMicroSeconds() == GetTbtt().GetMicroSeconds());     // assert that beacon is just on time
   
  // Form & send beacon
  MeshWifiBeacon beacon (GetSsid (), GetSupportedRates (), m_beaconInterval.GetMicroSeconds ());
  
  // Ask all plugins to add their specific information elements to beacon
  for (PluginList::const_iterator i = m_plugins.begin(); i != m_plugins.end(); ++i)
    (*i)->UpdateBeacon (beacon);
  
  m_beaconDca->Queue (beacon.CreatePacket(), beacon.CreateHeader(GetAddress()));
  
  ScheduleNextBeacon ();
}

void
MeshWifiInterfaceMac::Receive (Ptr<Packet> packet, WifiMacHeader const *hdr)
{
  // Process beacon
  if (hdr->IsBeacon ())
    {
      MgtBeaconHeader beacon_hdr;
      Mac48Address from = hdr->GetAddr2 ();
      
      packet->PeekHeader (beacon_hdr);
      
      NS_LOG_UNCOND ("Beacon received from "<<hdr->GetAddr2()<<
                   " to "<<GetAddress ()<<
                   " at "<<Simulator::Now ().GetMicroSeconds ()<<
                   " microseconds");
      
      // update supported rates
      if (beacon_hdr.GetSsid ().IsEqual(GetSsid()))
        {
          SupportedRates rates = beacon_hdr.GetSupportedRates ();
          WifiRemoteStation * peerSta = m_stationManager->Lookup (hdr->GetAddr2 ());
      
          for (uint32_t i = 0; i < m_phy->GetNModes (); i++)
          {
            WifiMode mode = m_phy->GetMode (i);
            if (rates.IsSupportedRate (mode.GetDataRate ()))
              {
                peerSta->AddSupportedMode (mode);
                if (rates.IsBasicRate (mode.GetDataRate ()))
                  m_stationManager->AddBasicMode (mode);
              }
          }
        }
    }
  
  // Filter frame through all installed plugins
  for (PluginList::iterator i = m_plugins.begin (); i != m_plugins.end(); ++i)
    {
      bool drop = ! ((*i)->Receive(packet, *hdr));
      if (drop) return; // plugin drops frame
    }
    
  // Forward data up
  if (hdr->IsData ())
      ForwardUp (packet, hdr->GetAddr4(), hdr->GetAddr3());
}

} // namespace ns3