/*
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

// Network topology
//
//  n0
//     \ 5 Mb/s, 2ms
//      \          1.5Mb/s, 10ms
//       n2 -------------------------n3
//      /
//     / 5 Mb/s, 2ms
//   n1
//
// - all links are point-to-point links with indicated one-way BW/delay
// - CBR/UDP flows from n0 to n3, and from n3 to n1
// - FTP/TCP flow from n0 to n3, starting at time 1.2 to time 1.35 sec.
// - UDP packet size of 210 bytes, with per-packet interval 0.00375 sec.
//   (i.e., DataRate of 448,000 bps)
// - DropTail queues
// - Tracing of queues and packet receptions to file
//   "simple-error-model.tr"

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

#include <fstream>

using namespace ns3;

NS_LOG_COMPONENT_DEFINE("SimpleErrorModelExample");

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
#if 0
  LogComponentEnable ("SimplePointToPointExample", LOG_LEVEL_INFO);
#endif

    // Set a few attributes
    Config::SetDefault("ns3::RateErrorModel::ErrorRate", DoubleValue(0.001));
    Config::SetDefault("ns3::RateErrorModel::ErrorUnit", StringValue("ERROR_UNIT_PACKET"));

    Config::SetDefault("ns3::BurstErrorModel::ErrorRate", DoubleValue(0.01));
    Config::SetDefault("ns3::BurstErrorModel::BurstSize",
                       StringValue("ns3::UniformRandomVariable[Min=1|Max=3]"));

    Config::SetDefault("ns3::OnOffApplication::PacketSize", UintegerValue(210));
    Config::SetDefault("ns3::OnOffApplication::DataRate", DataRateValue(DataRate("448kb/s")));

    std::string errorModelType = "ns3::RateErrorModel";

    // Allow the user to override any of the defaults and the above
    // Bind()s at run-time, via command-line arguments
    CommandLine cmd(__FILE__);
    cmd.AddValue("errorModelType", "TypeId of the error model to use", errorModelType);
    cmd.Parse(argc, argv);

    // Here, we will explicitly create four nodes.  In more sophisticated
    // topologies, we could configure a node factory.
    NS_LOG_INFO("Create nodes.");
    NodeContainer c;
    c.Create(4);
    NodeContainer n0n2 = NodeContainer(c.Get(0), c.Get(2));
    NodeContainer n1n2 = NodeContainer(c.Get(1), c.Get(2));
    NodeContainer n3n2 = NodeContainer(c.Get(3), c.Get(2));

    InternetStackHelper internet;
    internet.Install(c);

    // We create the channels first without any IP addressing information
    NS_LOG_INFO("Create channels.");
    PointToPointHelper p2p;
    p2p.SetDeviceAttribute("DataRate", DataRateValue(DataRate(5000000)));
    p2p.SetChannelAttribute("Delay", TimeValue(MilliSeconds(2)));
    NetDeviceContainer d0d2 = p2p.Install(n0n2);

    NetDeviceContainer d1d2 = p2p.Install(n1n2);

    p2p.SetDeviceAttribute("DataRate", DataRateValue(DataRate(1500000)));
    p2p.SetChannelAttribute("Delay", TimeValue(MilliSeconds(10)));
    NetDeviceContainer d3d2 = p2p.Install(n3n2);

    // Later, we add IP addresses.
    NS_LOG_INFO("Assign IP Addresses.");
    Ipv4AddressHelper ipv4;
    ipv4.SetBase("10.1.1.0", "255.255.255.0");
    ipv4.Assign(d0d2);

    ipv4.SetBase("10.1.2.0", "255.255.255.0");
    Ipv4InterfaceContainer i1i2 = ipv4.Assign(d1d2);

    ipv4.SetBase("10.1.3.0", "255.255.255.0");
    Ipv4InterfaceContainer i3i2 = ipv4.Assign(d3d2);

    NS_LOG_INFO("Use global routing.");
    Ipv4GlobalRoutingHelper::PopulateRoutingTables();

    // Create the OnOff application to send UDP datagrams of size
    // 210 bytes at a rate of 448 Kb/s
    NS_LOG_INFO("Create Applications.");
    uint16_t port = 9; // Discard port (RFC 863)

    OnOffHelper onoff("ns3::UdpSocketFactory",
                      Address(InetSocketAddress(i3i2.GetAddress(1), port)));
    onoff.SetConstantRate(DataRate("448kb/s"));
    ApplicationContainer apps = onoff.Install(c.Get(0));
    apps.Start(Seconds(1));
    apps.Stop(Seconds(10));

    // Create an optional packet sink to receive these packets
    PacketSinkHelper sink("ns3::UdpSocketFactory",
                          Address(InetSocketAddress(Ipv4Address::GetAny(), port)));
    apps = sink.Install(c.Get(2));
    apps.Start(Seconds(1));
    apps.Stop(Seconds(10));

    // Create a similar flow from n3 to n1, starting at time 1.1 seconds
    onoff.SetAttribute("Remote", AddressValue(InetSocketAddress(i1i2.GetAddress(0), port)));
    apps = onoff.Install(c.Get(3));
    apps.Start(Seconds(1.1));
    apps.Stop(Seconds(10));

    // Create a packet sink to receive these packets
    sink.SetAttribute("Local", AddressValue(InetSocketAddress(Ipv4Address::GetAny(), port)));
    apps = sink.Install(c.Get(1));
    apps.Start(Seconds(1.1));
    apps.Stop(Seconds(10));

    //
    // Error model
    //
    // Create an ErrorModel based on the implementation (constructor)
    // specified by the default TypeId

    ObjectFactory factory;
    factory.SetTypeId(errorModelType);
    Ptr<ErrorModel> em = factory.Create<ErrorModel>();
    d3d2.Get(0)->SetAttribute("ReceiveErrorModel", PointerValue(em));

    // Now, let's use the ListErrorModel and explicitly force a loss
    // of the packets with pkt-uids = 11 and 17 on node 2, device 0
    std::list<uint64_t> sampleList;
    sampleList.push_back(11);
    sampleList.push_back(17);
    // This time, we'll explicitly create the error model we want
    Ptr<ListErrorModel> pem = CreateObject<ListErrorModel>();
    pem->SetList(sampleList);
    d0d2.Get(1)->SetAttribute("ReceiveErrorModel", PointerValue(pem));

    AsciiTraceHelper ascii;
    p2p.EnableAsciiAll(ascii.CreateFileStream("simple-error-model.tr"));
    p2p.EnablePcapAll("simple-error-model");

    NS_LOG_INFO("Run Simulation.");
    Simulator::Run();
    Simulator::Destroy();
    NS_LOG_INFO("Done.");

    return 0;
}
