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

#include <sstream>
#include "ns3/core-module.h"
#include "ns3/network-module.h"
#include "ns3/csma-module.h"
#include "ns3/internet-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/applications-module.h"
#include "ns3/ipv4-global-routing-helper.h"

// Default Network Topology
//
//       10.1.1.0
// n0 -------------- n1   n2   n3   n4
//    point-to-point  |    |    |    |
//                    ================
//                      LAN 10.1.2.0


using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("BusExercise");

int 
main (int argc, char *argv[])
{
  bool verbose = true;
  uint32_t nCsma = 3;
  uint32_t maxPackets = 1;
  uint32_t nEchoClients = 1;

  CommandLine cmd;
  cmd.AddValue ("nCsma", "Number of \"extra\" CSMA nodes/devices", nCsma);
  cmd.AddValue ("verbose", "Tell echo applications to log if true", verbose);
  cmd.AddValue ("maxPackets", "Number of max packets sent from the client", maxPackets);
  cmd.AddValue ("nEchoClients", "Number of echo clients on the CSMA channel", nEchoClients);

  cmd.Parse (argc,argv);

  if (verbose)
  {
    LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_INFO);
    LogComponentEnable ("UdpEchoServerApplication", LOG_LEVEL_INFO);
  }

  nCsma = nCsma == 0 ? 1 : nCsma;
  // At least 1 clients and at most nCsma.
  nEchoClients = nEchoClients >= nCsma ? nCsma : (nEchoClients == 0 ? 1 : nEchoClients);

  NodeContainer p2pNodes;
  p2pNodes.Create (2);

  NodeContainer csmaNodes;
  csmaNodes.Add (p2pNodes.Get (1));
  csmaNodes.Create (nCsma);

  PointToPointHelper pointToPoint;
  pointToPoint.SetDeviceAttribute ("DataRate", StringValue ("5Mbps"));
  pointToPoint.SetChannelAttribute ("Delay", StringValue ("2ms"));

  NetDeviceContainer p2pDevices;
  p2pDevices = pointToPoint.Install (p2pNodes);

  CsmaHelper csma;
  csma.SetChannelAttribute ("DataRate", StringValue ("100Mbps"));
  csma.SetChannelAttribute ("Delay", TimeValue (NanoSeconds (6560)));

  NetDeviceContainer csmaDevices;
  csmaDevices = csma.Install (csmaNodes);

  InternetStackHelper stack;
  stack.Install (p2pNodes.Get (0)); 
  stack.Install (csmaNodes);

  Ipv4AddressHelper address;
  address.SetBase ("10.1.1.0", "255.255.255.0");
  Ipv4InterfaceContainer p2pInterfaces;
  p2pInterfaces = address.Assign (p2pDevices);

  address.SetBase ("10.1.2.0", "255.255.255.0");
  Ipv4InterfaceContainer csmaInterfaces;
  csmaInterfaces = address.Assign (csmaDevices);

  UdpEchoServerHelper echoServer (9);
  // We now install the server on n0, rather than the rightmost node.
  ApplicationContainer serverApps = echoServer.Install (p2pNodes.Get (0));
  serverApps.Start (Seconds (1.0));
  serverApps.Stop (Seconds (10.0));

  UdpEchoClientHelper echoClient (p2pInterfaces.GetAddress (0), 9);
  echoClient.SetAttribute ("MaxPackets", UintegerValue (maxPackets));
  echoClient.SetAttribute ("Interval", TimeValue (Seconds (1.0)));
  echoClient.SetAttribute ("PacketSize", UintegerValue (1024));

  // Echo clients are installed on "extra" CSMA nodes.
  // Because n1 would send the packet through the P2P link directly,
  // without involving the CSMA bus. 
  for (uint32_t i = 1; i <= nEchoClients; i++)
  {
    ApplicationContainer clientApps = echoClient.Install (csmaNodes.Get (i));
    clientApps.Start (Seconds (2.0));
    clientApps.Stop (Seconds (10.0));
  }

  Ipv4GlobalRoutingHelper::PopulateRoutingTables ();

  std::stringstream pcapName;
  pcapName << "bus-" << nCsma;
  pointToPoint.EnablePcapAll (pcapName.str());
  csma.EnablePcap (pcapName.str(), csmaDevices.Get (0), true);

  Simulator::Run ();
  Simulator::Destroy ();
  return 0;
}