#include <iostream>

#include "ns3/core-module.h"
#include "ns3/helper-module.h"
#include "ns3/node-module.h"
#include "ns3/simulator-module.h"

using namespace ns3;

static void
GenerateTraffic (Ptr<Socket> socket, uint32_t size)
{
  std::cout << "at=" << Simulator::Now ().GetSeconds () << "s, tx bytes=" << size << std::endl;
  socket->Send (Create<Packet> (size));
  if (size > 0)
    {
      Simulator::Schedule (Seconds (0.5), &GenerateTraffic, socket, size - 50);
    }
  else
    {
      socket->Close ();
    }
}

static void
SocketPrinter (Ptr<Socket> socket)
{
  Ptr<Packet> packet;
  uint32_t maxSize = std::numeric_limits<uint32_t>::max();
  uint32_t flags = 0;  // no flags
  while (packet = socket->Recv (maxSize, flags))
    { 
      std::cout << "at=" << Simulator::Now ().GetSeconds () << "s, rx bytes=" << packet->GetSize () << std::endl;
    }
}

static void
PrintTraffic (Ptr<Socket> socket)
{
  socket->SetRecv_Callback (MakeCallback (&SocketPrinter));
}

void
RunSimulation (void)
{
  NodeContainer c;
  c.Create (1);

  InternetStackHelper internet;
  internet.Install (c);


  TypeId tid = TypeId::LookupByName ("ns3::Udp");
  Ptr<SocketFactory> socketFactory = c.Get (0)->GetObject<SocketFactory> (tid);

  Ptr<Socket> sink = socketFactory->CreateSocket ();
  InetSocketAddress local = InetSocketAddress (Ipv4Address::GetAny (), 80);
  sink->Bind (local);

  Ptr<Socket> source = socketFactory->CreateSocket ();
  InetSocketAddress remote = InetSocketAddress (Ipv4Address::GetLoopback (), 80);
  source->Connect (remote);

  GenerateTraffic (source, 500);
  PrintTraffic (sink);


  Simulator::Run ();

  Simulator::Destroy ();
}

int main (int argc, char *argv[])
{
  RunSimulation ();

  return 0;
}