/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2009 MIRKO BANCHI
 * Copyright (c) 2015 University of Washington
 *
 * 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: Mirko Banchi <mk.banchi@gmail.com>
 *          Sebastien Deronne <sebastien.deronne@gmail.com>
 *          Tom Henderson <tomhend@u.washington.edu>
 *
 * Adapted from ht-wifi-network.cc example
 */
#include <sstream>
#include <iomanip>

#include "ns3/core-module.h"
#include "ns3/config-store-module.h"
#include "ns3/network-module.h"
#include "ns3/applications-module.h"
#include "ns3/wifi-module.h"
#include "ns3/mobility-module.h"
#include "ns3/spectrum-module.h"
#include "ns3/internet-module.h"

// This is a simple example of an IEEE 802.11n Wi-Fi network.
//
// The main use case is to enable and test SpectrumWifiPhy vs YansWifiPhy
// for packet error ratio
//
// Network topology:
//
//  Wi-Fi 192.168.1.0
//
//   STA                  AP
//    * <-- distance -->  *
//    |                   |
//    n1                  n2
//
//  Adapted version of wifi-spectrum-per-example.cc to show the
//  channel switching bug with WifiSpectrumPhy
//
//
//

using namespace ns3;

// Global variables for use in callbacks.
double g_signalDbmAvg;
double g_noiseDbmAvg;
uint32_t g_samples;
uint16_t g_channelNumber;
uint32_t g_rate;

void MonitorSniffRx (Ptr<const Packet> packet,
                     uint16_t channelFreqMhz,
                     WifiTxVector txVector,
                     MpduInfo aMpdu,
                     SignalNoiseDbm signalNoise)

{
  g_samples++;
  g_signalDbmAvg += ((signalNoise.signal - g_signalDbmAvg) / g_samples);
  g_noiseDbmAvg += ((signalNoise.noise - g_noiseDbmAvg) / g_samples);
}

NS_LOG_COMPONENT_DEFINE ("WifiSpectrumPerExample");



// Bug-Related function
void ChangeFrequencyLocal (NetDeviceContainer deviceslink, uint8_t channel){
  for (uint32_t i = 0; i < deviceslink.GetN (); i++)
    {
      Ptr<WifiNetDevice> wifidevice = DynamicCast<WifiNetDevice> (deviceslink.Get(i));
      Ptr<WifiPhy> phy0 = wifidevice->GetPhy();
      phy0->SetChannelNumber (channel);
      //phy0->SetFrequency (5190); Makes no difference
      //phy0->SetChannelWidth (40); Makes no difference
      std::cout << "Changed channel on " << deviceslink.Get (i)->GetAddress () << "  to:  "
      << channel << std::endl;
    }
}

int main (int argc, char *argv[])
{
  bool udp = true;
  double distance = 50;
  double simulationTime = 10; //seconds
  std::string wifiType = "ns3::SpectrumWifiPhy";
  std::string errorModelType = "ns3::NistErrorRateModel";
  bool enablePcap = true;
  const uint32_t tcpPacketSize = 1448;

  CommandLine cmd;
  cmd.AddValue ("simulationTime", "Simulation time in seconds", simulationTime);
  cmd.AddValue ("udp", "UDP if set to 1, TCP otherwise", udp);
  cmd.AddValue ("distance", "meters separation between nodes", distance);
  cmd.AddValue ("wifiType", "select ns3::SpectrumWifiPhy or ns3::YansWifiPhy", wifiType);
  cmd.AddValue ("errorModelType", "select ns3::NistErrorRateModel or ns3::YansErrorRateModel", errorModelType);
  cmd.AddValue ("enablePcap", "enable pcap output", enablePcap);
  cmd.Parse (argc,argv);




  // Configure Debug Function
  LogLevel logLevel = (LogLevel) (LOG_PREFIX_FUNC | LOG_PREFIX_NODE | LOG_PREFIX_TIME | LOG_LEVEL_DEBUG);
  //std::cout << logLevel << std::endl;
  LogComponentEnable ("WifiPhy", logLevel);

  std::cout << "wifiType: " << wifiType << " distance: " << distance << "m; sent: 1000 TxPower: 1 dBm (1.3 mW)" << std::endl;
  std::cout << std::setw (5) << "index" <<
               std::setw (6) << "MCS" <<
               std::setw (12) << "Rate (Mb/s)" <<
               std::setw (12) << "Tput (Mb/s)" <<
               std::setw (10) << "Received " <<
               std::setw (12) << "Signal (dBm)" <<
               std::setw (12) << "Noise (dBm)" <<
               std::setw (10) << "SNR (dB)" <<
               std::endl;


  uint16_t i=0; //stripped down version
  uint32_t payloadSize;
  if (udp)
    {
      payloadSize = 972; // 1000 bytes IPv4
    }
  else
    {
      payloadSize = 1448; // 1500 bytes IPv6
      Config::SetDefault ("ns3::TcpSocket::SegmentSize", UintegerValue (payloadSize));
    }

  NodeContainer wifiStaNode;
  wifiStaNode.Create (1);
  NodeContainer wifiApNode;
  wifiApNode.Create (1);

  YansWifiPhyHelper phy = YansWifiPhyHelper::Default ();
  SpectrumWifiPhyHelper spectrumPhy = SpectrumWifiPhyHelper::Default ();
  if (wifiType == "ns3::YansWifiPhy")
    {
      YansWifiChannelHelper channel;
      channel.AddPropagationLoss ("ns3::FriisPropagationLossModel");
      channel.SetPropagationDelay ("ns3::ConstantSpeedPropagationDelayModel");
      phy.SetChannel (channel.Create ());
      phy.Set ("TxPowerStart", DoubleValue (1)); // dBm (1.26 mW)
      phy.Set ("TxPowerEnd", DoubleValue (1));


      phy.Set ("ShortGuardEnabled", BooleanValue (false));
      phy.Set ("ChannelWidth", UintegerValue (20));

    }
  else if (wifiType == "ns3::SpectrumWifiPhy")
    {
      //Bug 2460: CcaMode1Threshold default should be set to -62 dBm when using Spectrum
      Config::SetDefault ("ns3::WifiPhy::CcaMode1Threshold", DoubleValue (-62.0));

      Ptr<MultiModelSpectrumChannel> spectrumChannel
          = CreateObject<MultiModelSpectrumChannel> ();
      Ptr<FriisPropagationLossModel> lossModel
          = CreateObject<FriisPropagationLossModel> ();
      spectrumChannel->AddPropagationLossModel (lossModel);

      Ptr<ConstantSpeedPropagationDelayModel> delayModel
          = CreateObject<ConstantSpeedPropagationDelayModel> ();
      spectrumChannel->SetPropagationDelayModel (delayModel);

      spectrumPhy.SetChannel (spectrumChannel);
      spectrumPhy.SetErrorRateModel (errorModelType);
      spectrumPhy.Set ("Frequency", UintegerValue (5180));
      spectrumPhy.Set ("TxPowerStart", DoubleValue (1)); // dBm  (1.26 mW)
      spectrumPhy.Set ("TxPowerEnd", DoubleValue (1));


      spectrumPhy.Set ("ShortGuardEnabled", BooleanValue (false));
      spectrumPhy.Set ("ChannelWidth", UintegerValue (20));
    }
  else
    {
      NS_FATAL_ERROR ("Unsupported WiFi type " << wifiType);
    }


  WifiHelper wifi;
  wifi.SetStandard (WIFI_PHY_STANDARD_80211n_5GHZ);
  WifiMacHelper mac;

  Ssid ssid = Ssid ("ns380211n");

  double datarate = 0;
  StringValue DataRate;
  DataRate = StringValue ("HtMcs0");
  datarate = 6.5;

  wifi.SetRemoteStationManager ("ns3::ConstantRateWifiManager","DataMode", DataRate,
                                "ControlMode", DataRate);

  NetDeviceContainer staDevice;
  NetDeviceContainer apDevice;

  if (wifiType == "ns3::YansWifiPhy")
    {
      mac.SetType ("ns3::StaWifiMac",
                   "Ssid", SsidValue (ssid),
                   "ActiveProbing", BooleanValue (false));
      staDevice = wifi.Install (phy, mac, wifiStaNode);
      mac.SetType ("ns3::ApWifiMac",
                   "Ssid", SsidValue (ssid));
      apDevice = wifi.Install (phy, mac, wifiApNode);

    }
  else if (wifiType == "ns3::SpectrumWifiPhy")
    {
      mac.SetType ("ns3::StaWifiMac",
                   "Ssid", SsidValue (ssid),
                   "ActiveProbing", BooleanValue (false));
      staDevice = wifi.Install (spectrumPhy, mac, wifiStaNode);
      mac.SetType ("ns3::ApWifiMac",
                   "Ssid", SsidValue (ssid));
      apDevice = wifi.Install (spectrumPhy, mac, wifiApNode);
    }

  // mobility.
  MobilityHelper mobility;
  Ptr<ListPositionAllocator> positionAlloc = CreateObject<ListPositionAllocator> ();

  positionAlloc->Add (Vector (0.0, 0.0, 0.0));
  positionAlloc->Add (Vector (distance, 0.0, 0.0));
  mobility.SetPositionAllocator (positionAlloc);

  mobility.SetMobilityModel ("ns3::ConstantPositionMobilityModel");

  mobility.Install (wifiApNode);
  mobility.Install (wifiStaNode);

  /* Internet stack*/
  InternetStackHelper stack;
  stack.Install (wifiApNode);
  stack.Install (wifiStaNode);

  Ipv4AddressHelper address;

  address.SetBase ("192.168.1.0", "255.255.255.0");
  Ipv4InterfaceContainer staNodeInterface;
  Ipv4InterfaceContainer apNodeInterface;

  staNodeInterface = address.Assign (staDevice);
  apNodeInterface = address.Assign (apDevice);

  /* Setting applications */
  ApplicationContainer serverApp, sinkApp;
  if (udp)
    {
      //UDP flow
      UdpServerHelper myServer (9);
      serverApp = myServer.Install (wifiStaNode.Get (0));
      serverApp.Start (Seconds (0.0));
      serverApp.Stop (Seconds (simulationTime + 1));

      UdpClientHelper myClient (staNodeInterface.GetAddress (0), 9);
      myClient.SetAttribute ("MaxPackets", UintegerValue (1000));
      myClient.SetAttribute ("Interval", TimeValue (MilliSeconds (5)));
      myClient.SetAttribute ("PacketSize", UintegerValue (payloadSize));

      ApplicationContainer clientApp = myClient.Install (wifiApNode.Get (0));
      clientApp.Start (Seconds (1.0));
      clientApp.Stop (Seconds (simulationTime + 1));
    }
  else
    {
      //TCP flow
      uint16_t port = 50000;
      Address apLocalAddress (InetSocketAddress (Ipv4Address::GetAny (), port));
      PacketSinkHelper packetSinkHelper ("ns3::TcpSocketFactory", apLocalAddress);
      sinkApp = packetSinkHelper.Install (wifiStaNode.Get (0));

      sinkApp.Start (Seconds (0.0));
      sinkApp.Stop (Seconds (simulationTime + 1));

      OnOffHelper onoff ("ns3::TcpSocketFactory",Ipv4Address::GetAny ());
      onoff.SetAttribute ("OnTime",  StringValue ("ns3::ConstantRandomVariable[Constant=1]"));
      onoff.SetAttribute ("OffTime", StringValue ("ns3::ConstantRandomVariable[Constant=0]"));
      onoff.SetAttribute ("PacketSize", UintegerValue (payloadSize));
      onoff.SetAttribute ("DataRate", DataRateValue (1000000000)); //bit/s
      ApplicationContainer apps;

      AddressValue remoteAddress (InetSocketAddress (staNodeInterface.GetAddress (0), port));
      onoff.SetAttribute ("Remote", remoteAddress);
      apps.Add (onoff.Install (wifiApNode.Get (0)));
      apps.Start (Seconds (1.0));
      apps.Stop (Seconds (simulationTime + 1));
    }

  Config::ConnectWithoutContext ("/NodeList/0/DeviceList/*/Phy/MonitorSnifferRx", MakeCallback (&MonitorSniffRx));

  g_signalDbmAvg = 0;
  g_noiseDbmAvg = 0;
  g_samples = 0;
  g_channelNumber = 0;
  g_rate = 0;

  NetDeviceContainer devices;
  devices.Add (apDevice);
  devices.Add (staDevice);

  if (enablePcap)
    {
      spectrumPhy.SetPcapDataLinkType (SpectrumWifiPhyHelper::DLT_IEEE802_11_RADIO);
      phy.SetPcapDataLinkType (YansWifiPhyHelper::DLT_IEEE802_11_RADIO);
      std::stringstream ss;
      ss << "channel-switch-minimal";
      spectrumPhy.EnablePcap (ss.str(), devices); //enable pcap output for all devices use tcpdump -r exam1-0-1.pcap -nn -tt
    }


  // Bug-Related function call here.

  //ChangeFrequencyLocal (devices, 44); // This works since it is executed before the simulation starts.

  Simulator::Stop (Seconds (simulationTime + 1));
  Simulator::Schedule(Seconds(simulationTime-5), &ChangeFrequencyLocal, devices, 38); // This does not work with SpectrumWifiPhy
  Simulator::Run ();

  double throughput = 0;
  uint32_t totalPacketsThrough = 0;
  if (udp)
    {
      //UDP
      totalPacketsThrough = DynamicCast<UdpServer> (serverApp.Get (0))->GetReceived ();
      throughput = totalPacketsThrough * payloadSize * 8 / (simulationTime * 1000000.0); //Mbit/s
    }
  else
    {
      //TCP
      uint32_t totalBytesRx = DynamicCast<PacketSink> (sinkApp.Get (0))->GetTotalRx ();
      totalPacketsThrough = totalBytesRx / tcpPacketSize;
      throughput = totalBytesRx * 8 / (simulationTime * 1000000.0); //Mbit/s
    }
  std::cout << std::setw (5) << i <<
               std::setw (6) << (i % 8) <<
               std::setw (10) << datarate <<
               std::setw (12) << throughput <<
               std::setw (8) << totalPacketsThrough;
  if (totalPacketsThrough > 0)
    {
      std::cout << std::setw (12) << g_signalDbmAvg <<
                   std::setw (12) << g_noiseDbmAvg <<
                   std::setw (12) << (g_signalDbmAvg - g_noiseDbmAvg) <<
                   std::endl;
    }
  else
    {
      std::cout << std::setw (12) << "N/A" <<
                   std::setw (12) << "N/A" <<
                   std::setw (12) << "N/A" <<
                   std::endl;
    }


  Simulator::Destroy ();

  return 0;
}