/* -*- 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

 *

 */

// Default Network topology, 9 nodes in a star

/*

          n2 n3 n4

           \ | /

            \|/

       n1---n0---n5

            /|\

           / | \

          n8 n7 n6

*/

// - CBR Traffic goes from the star "arms" to the "hub"

// - Tracing of queues and packet receptions to file

//   "tcp-star-server.tr"

// - pcap traces also generated in the following files

//   "tcp-star-server-$n-$i.pcap" where n and i represent node and interface

//   numbers respectively

// Usage examples for things you might want to tweak:

//       ./waf --run="tcp-star-server"

//       ./waf --run="tcp-star-server --nNodes=25"

//       ./waf --run="tcp-star-server --ns3::OnOffApplication::DataRate=10000"

//       ./waf --run="tcp-star-server --ns3::OnOffApplication::PacketSize=500"

// See the ns-3 tutorial for more info on the command line: 

// http://www.nsnam.org/tutorials.html

#include <iostream>

#include <fstream>

#include <string>

#include <cassert>

#include "ns3/core-module.h"

#include "ns3/simulator-module.h"

#include "ns3/node-module.h"

#include "ns3/helper-module.h"

#include "ns3/global-route-manager.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("TcpServer");

int 

main (int argc, char *argv[])

{

  // Users may find it convenient to turn on explicit debugging

  // for selected modules; the below lines suggest how to do this

  //LogComponentEnable ("TcpServer", LOG_LEVEL_INFO);

  //LogComponentEnable ("TcpL4Protocol", LOG_LEVEL_ALL);

  //LogComponentEnable ("TcpSocketImpl", LOG_LEVEL_ALL);

  //LogComponentEnable ("PacketSink", LOG_LEVEL_ALL);

  //

  // Make the random number generators generate reproducible results.

  //

  RandomVariable::UseGlobalSeed (1, 1, 2, 3, 5, 8);

  // Set up some default values for the simulation.

  Config::SetDefault ("ns3::OnOffApplication::PacketSize", UintegerValue (250));

  Config::SetDefault ("ns3::OnOffApplication::DataRate", StringValue ("5kb/s"));

  uint32_t N = 9; //number of nodes in the star

  // Allow the user to override any of the defaults and the above

  // Config::SetDefault()s at run-time, via command-line arguments

  CommandLine cmd;

  cmd.AddValue("nNodes", "Number of nodes to place in the star", N);

  cmd.Parse (argc, argv);

  // Here, we will create N nodes in a star.

  NS_LOG_INFO ("Create nodes.");

  NodeContainer serverNode;

  NodeContainer clientNodes;

  serverNode.Create(1);

  clientNodes.Create(N-1);

  NodeContainer allNodes = NodeContainer(serverNode, clientNodes);

  // Install network stacks on the nodes

  InternetStackHelper internet;

  internet.Install (allNodes);

  //Collect an adjacency list of nodes for the p2p topology

  std::vector<NodeContainer> nodeAdjacencyList(N-1);

  for(uint32_t i=0; i<nodeAdjacencyList.size(); ++i)

  {

    nodeAdjacencyList[i] = NodeContainer (serverNode, clientNodes.Get (i));

  }

  // We create the channels first without any IP addressing information

  NS_LOG_INFO ("Create channels.");

  PointToPointHelper p2p;

  p2p.SetDeviceAttribute ("DataRate", StringValue ("5Mbps"));

  p2p.SetChannelAttribute ("Delay", StringValue ("2ms"));

  std::vector<NetDeviceContainer> deviceAdjacencyList(N-1);

  for(uint32_t i=0; i<deviceAdjacencyList.size(); ++i)

  {

    deviceAdjacencyList[i] = p2p.Install (nodeAdjacencyList[i]);

  }

  // Later, we add IP addresses.  

  NS_LOG_INFO ("Assign IP Addresses.");

  Ipv4AddressHelper ipv4;

  std::vector<Ipv4InterfaceContainer> interfaceAdjacencyList(N-1);

  for(uint32_t i=0; i<interfaceAdjacencyList.size(); ++i)

  {

    std::ostringstream subnet;

    subnet<<"10.1."<<i+1<<".0";

    ipv4.SetBase (subnet.str().c_str(), "255.255.255.0");

    interfaceAdjacencyList[i] = ipv4.Assign (deviceAdjacencyList[i]);

  }

  //Turn on global static routing

  GlobalRouteManager::PopulateRoutingTables ();

  // Create a packet sink on the star "hub" to receive these packets

  uint16_t port = 50000;

  Address sinkLocalAddress(InetSocketAddress (Ipv4Address::GetAny (), port));

  PacketSinkHelper sinkHelper ("ns3::TcpSocketFactory", sinkLocalAddress);

  ApplicationContainer sinkApp = sinkHelper.Install (serverNode);

  sinkApp.Start (Seconds (1.0));

  sinkApp.Stop (Seconds (10.0));

  // Create the OnOff applications to send TCP to the server

  OnOffHelper clientHelper ("ns3::TcpSocketFactory", Address ());

  clientHelper.SetAttribute 

      ("OnTime", RandomVariableValue (ConstantVariable (1)));

  clientHelper.SetAttribute 

      ("OffTime", RandomVariableValue (ConstantVariable (0)));

  //normally wouldn't need a loop here but the server IP address is different

  //on each p2p subnet

  ApplicationContainer clientApps;

  for(uint32_t i=0; i<clientNodes.GetN(); ++i)

  {

    AddressValue remoteAddress

        (InetSocketAddress (interfaceAdjacencyList[i].GetAddress (0), port));

    clientHelper.SetAttribute ("Remote", remoteAddress);

    clientApps.Add(clientHelper.Install (clientNodes.Get(i)));

  }

  clientApps.Start (Seconds (1.0));

  clientApps.Stop (Seconds (10.0));

  //configure tracing

  std::ofstream ascii;

  ascii.open ("tcp-star-server.tr");

  PointToPointHelper::EnablePcapAll ("tcp-star-server");

  PointToPointHelper::EnableAsciiAll (ascii);

  NS_LOG_INFO ("Run Simulation.");

  Simulator::Run ();

  Simulator::Destroy ();

  NS_LOG_INFO ("Done.");

  return 0;

}