/*
 * Copyright (c) 2015 Universita' degli Studi di Napoli Federico II
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Authors: Pasquale Imputato <p.imputato@gmail.com>
 *          Stefano Avallone <stefano.avallone@unina.it>
 */

// This example serves as a benchmark for all the queue discs (with BQL enabled or not)
//
// Network topology
//
//                192.168.1.0                             192.168.2.0
// n1 ------------------------------------ n2 ----------------------------------- n3
//   point-to-point (access link)                point-to-point (bottleneck link)
//   100 Mbps, 0.1 ms                            bandwidth [10 Mbps], delay [5 ms]
//   qdiscs PfifoFast with capacity              qdiscs queueDiscType in {PfifoFast, ARED, CoDel,
//   FqCoDel, PIE} [PfifoFast] of 1000 packets                             with capacity of
//   queueDiscSize packets [1000] netdevices queues with size of 100 packets  netdevices queues with
//   size of netdevicesQueueSize packets [100] without BQL                                 bql BQL
//   [false]
//   *** fixed configuration ***
//
// Two TCP flows are generated: one from n1 to n3 and the other from n3 to n1.
// Additionally, n1 pings n3, so that the RTT can be measured.
//
// The output will consist of a number of ping Rtt such as:
//
//    /NodeList/0/ApplicationList/2/$ns3::Ping/Rtt=111 ms
//    /NodeList/0/ApplicationList/2/$ns3::Ping/Rtt=111 ms
//    /NodeList/0/ApplicationList/2/$ns3::Ping/Rtt=110 ms
//    /NodeList/0/ApplicationList/2/$ns3::Ping/Rtt=111 ms
//    /NodeList/0/ApplicationList/2/$ns3::Ping/Rtt=111 ms
//    /NodeList/0/ApplicationList/2/$ns3::Ping/Rtt=112 ms
//    /NodeList/0/ApplicationList/2/$ns3::Ping/Rtt=111 ms
//
// The files output will consist of a trace file with bytes in queue and of a trace file for limits
// (when BQL is enabled) both for bottleneck NetDevice on n2, two files with upload and download
// goodput for flows configuration and a file with flow monitor stats.
//
// If you use an AQM as queue disc on the bottleneck netdevices, you can observe that the ping Rtt
// decrease. A further decrease can be observed when you enable BQL.

#include "ns3/applications-module.h"
#include "ns3/core-module.h"
#include "ns3/flow-monitor-module.h"
#include "ns3/internet-apps-module.h"
#include "ns3/internet-module.h"
#include "ns3/network-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/traffic-control-module.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE("BenchmarkQueueDiscs");

/**
 * Print the queue limits.
 *
 * @param stream The output stream.
 * @param oldVal Old value.
 * @param newVal New value.
 */
void
LimitsTrace(Ptr<OutputStreamWrapper> stream, uint32_t oldVal, uint32_t newVal)
{
    *stream->GetStream() << Simulator::Now().GetSeconds() << " " << newVal << std::endl;
}

/**
 * Print the bytes in the queue.
 *
 * @param stream The output stream.
 * @param oldVal Old value.
 * @param newVal New value.
 */
void
BytesInQueueTrace(Ptr<OutputStreamWrapper> stream, uint32_t oldVal, uint32_t newVal)
{
    *stream->GetStream() << Simulator::Now().GetSeconds() << " " << newVal << std::endl;
}

/**
 * Sample and print the queue goodput.
 *
 * @param app The Tx app.
 * @param stream The output stream.
 * @param period The sampling period.
 */
static void
GoodputSampling(ApplicationContainer app, Ptr<OutputStreamWrapper> stream, float period)
{
    Simulator::Schedule(Seconds(period), &GoodputSampling, app, stream, period);
    double goodput;
    uint64_t totalPackets = DynamicCast<PacketSink>(app.Get(0))->GetTotalRx();
    goodput = totalPackets * 8 / (Simulator::Now().GetSeconds() * 1024); // Kbit/s
    *stream->GetStream() << Simulator::Now().GetSeconds() << " " << goodput << std::endl;
}

/**
 * Print the ping RTT.
 *
 * @param context The context.
 * @param rtt The RTT.
 */
static void
PingRtt(std::string context, uint16_t, Time rtt)
{
    std::cout << context << "=" << rtt.GetMilliSeconds() << " ms" << std::endl;
}

int
main(int argc, char* argv[])
{
    std::string bandwidth = "10Mbps";
    std::string delay = "5ms";
    std::string queueDiscType = "PfifoFast";
    uint32_t queueDiscSize = 1000;
    uint32_t netdevicesQueueSize = 50;
    bool bql = false;

    std::string flowsDatarate = "20Mbps";
    uint32_t flowsPacketsSize = 1000;

    float startTime = 0.1F; // in s
    float simDuration = 60;
    float samplingPeriod = 1;

    CommandLine cmd(__FILE__);
    cmd.AddValue("bandwidth", "Bottleneck bandwidth", bandwidth);
    cmd.AddValue("delay", "Bottleneck delay", delay);
    cmd.AddValue("queueDiscType",
                 "Bottleneck queue disc type in {PfifoFast, ARED, CoDel, FqCoDel, PIE, prio}",
                 queueDiscType);
    cmd.AddValue("queueDiscSize", "Bottleneck queue disc size in packets", queueDiscSize);
    cmd.AddValue("netdevicesQueueSize",
                 "Bottleneck netdevices queue size in packets",
                 netdevicesQueueSize);
    cmd.AddValue("bql", "Enable byte queue limits on bottleneck netdevices", bql);
    cmd.AddValue("flowsDatarate", "Upload and download flows datarate", flowsDatarate);
    cmd.AddValue("flowsPacketsSize", "Upload and download flows packets sizes", flowsPacketsSize);
    cmd.AddValue("startTime", "Simulation start time", startTime);
    cmd.AddValue("simDuration", "Simulation duration in seconds", simDuration);
    cmd.AddValue("samplingPeriod", "Goodput sampling period in seconds", samplingPeriod);
    cmd.Parse(argc, argv);

    float stopTime = startTime + simDuration;

    // Create nodes
    NodeContainer n1;
    NodeContainer n2;
    NodeContainer n3;
    n1.Create(1);
    n2.Create(1);
    n3.Create(1);

    // Create and configure access link and bottleneck link
    PointToPointHelper accessLink;
    accessLink.SetDeviceAttribute("DataRate", StringValue("100Mbps"));
    accessLink.SetChannelAttribute("Delay", StringValue("0.1ms"));
    accessLink.SetQueue("ns3::DropTailQueue", "MaxSize", StringValue("100p"));

    PointToPointHelper bottleneckLink;
    bottleneckLink.SetDeviceAttribute("DataRate", StringValue(bandwidth));
    bottleneckLink.SetChannelAttribute("Delay", StringValue(delay));
    bottleneckLink.SetQueue("ns3::DropTailQueue",
                            "MaxSize",
                            StringValue(std::to_string(netdevicesQueueSize) + "p"));

    InternetStackHelper stack;
    stack.InstallAll();

    // Access link traffic control configuration
    TrafficControlHelper tchPfifoFastAccess;
    tchPfifoFastAccess.SetRootQueueDisc("ns3::PfifoFastQueueDisc", "MaxSize", StringValue("1000p"));

    // Bottleneck link traffic control configuration
    TrafficControlHelper tchBottleneck;

    if (queueDiscType == "PfifoFast")
    {
        tchBottleneck.SetRootQueueDisc(
            "ns3::PfifoFastQueueDisc",
            "MaxSize",
            QueueSizeValue(QueueSize(QueueSizeUnit::PACKETS, queueDiscSize)));
    }
    else if (queueDiscType == "ARED")
    {
        tchBottleneck.SetRootQueueDisc("ns3::RedQueueDisc");
        Config::SetDefault("ns3::RedQueueDisc::ARED", BooleanValue(true));
        Config::SetDefault("ns3::RedQueueDisc::MaxSize",
                           QueueSizeValue(QueueSize(QueueSizeUnit::PACKETS, queueDiscSize)));
    }
    else if (queueDiscType == "CoDel")
    {
        tchBottleneck.SetRootQueueDisc("ns3::CoDelQueueDisc");
        Config::SetDefault("ns3::CoDelQueueDisc::MaxSize",
                           QueueSizeValue(QueueSize(QueueSizeUnit::PACKETS, queueDiscSize)));
    }
    else if (queueDiscType == "FqCoDel")
    {
        tchBottleneck.SetRootQueueDisc("ns3::FqCoDelQueueDisc");
        Config::SetDefault("ns3::FqCoDelQueueDisc::MaxSize",
                           QueueSizeValue(QueueSize(QueueSizeUnit::PACKETS, queueDiscSize)));
    }
    else if (queueDiscType == "PIE")
    {
        tchBottleneck.SetRootQueueDisc("ns3::PieQueueDisc");
        Config::SetDefault("ns3::PieQueueDisc::MaxSize",
                           QueueSizeValue(QueueSize(QueueSizeUnit::PACKETS, queueDiscSize)));
    }
    else if (queueDiscType == "prio")
    {
        uint16_t handle =
            tchBottleneck.SetRootQueueDisc("ns3::PrioQueueDisc",
                                           "Priomap",
                                           StringValue("0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1"));
        TrafficControlHelper::ClassIdList cid =
            tchBottleneck.AddQueueDiscClasses(handle, 2, "ns3::QueueDiscClass");
        tchBottleneck.AddChildQueueDisc(handle, cid[0], "ns3::FifoQueueDisc");
        tchBottleneck.AddChildQueueDisc(handle, cid[1], "ns3::RedQueueDisc");
    }
    else
    {
        NS_ABORT_MSG("--queueDiscType not valid");
    }

    if (bql)
    {
        tchBottleneck.SetQueueLimits("ns3::DynamicQueueLimits");
    }

    NetDeviceContainer devicesAccessLink = accessLink.Install(n1.Get(0), n2.Get(0));
    tchPfifoFastAccess.Install(devicesAccessLink);
    Ipv4AddressHelper address;
    address.SetBase("192.168.0.0", "255.255.255.0");
    address.NewNetwork();
    Ipv4InterfaceContainer interfacesAccess = address.Assign(devicesAccessLink);

    NetDeviceContainer devicesBottleneckLink = bottleneckLink.Install(n2.Get(0), n3.Get(0));
    QueueDiscContainer qdiscs;
    qdiscs = tchBottleneck.Install(devicesBottleneckLink);

    address.NewNetwork();
    Ipv4InterfaceContainer interfacesBottleneck = address.Assign(devicesBottleneckLink);

    Ptr<NetDeviceQueueInterface> interface =
        devicesBottleneckLink.Get(0)->GetObject<NetDeviceQueueInterface>();
    Ptr<NetDeviceQueue> queueInterface = interface->GetTxQueue(0);
    Ptr<DynamicQueueLimits> queueLimits =
        StaticCast<DynamicQueueLimits>(queueInterface->GetQueueLimits());

    AsciiTraceHelper ascii;
    if (bql)
    {
        queueDiscType = queueDiscType + "-bql";
        Ptr<OutputStreamWrapper> streamLimits =
            ascii.CreateFileStream(queueDiscType + "-limits.txt");
        queueLimits->TraceConnectWithoutContext("Limit",
                                                MakeBoundCallback(&LimitsTrace, streamLimits));
    }
    Ptr<Queue<Packet>> queue =
        StaticCast<PointToPointNetDevice>(devicesBottleneckLink.Get(0))->GetQueue();
    Ptr<OutputStreamWrapper> streamBytesInQueue =
        ascii.CreateFileStream(queueDiscType + "-bytesInQueue.txt");
    queue->TraceConnectWithoutContext("BytesInQueue",
                                      MakeBoundCallback(&BytesInQueueTrace, streamBytesInQueue));

    Ipv4InterfaceContainer n1Interface;
    n1Interface.Add(interfacesAccess.Get(0));

    Ipv4InterfaceContainer n3Interface;
    n3Interface.Add(interfacesBottleneck.Get(1));

    Ipv4GlobalRoutingHelper::PopulateRoutingTables();

    Config::SetDefault("ns3::TcpSocket::SegmentSize", UintegerValue(flowsPacketsSize));

    // Flows configuration
    // Bidirectional TCP streams with ping like flent tcp_bidirectional test.
    uint16_t port = 7;
    ApplicationContainer uploadApp;
    ApplicationContainer downloadApp;
    ApplicationContainer sourceApps;
    // Configure and install upload flow
    Address addUp(InetSocketAddress(Ipv4Address::GetAny(), port));
    PacketSinkHelper sinkHelperUp("ns3::TcpSocketFactory", addUp);
    sinkHelperUp.SetAttribute("Protocol", TypeIdValue(TcpSocketFactory::GetTypeId()));
    uploadApp.Add(sinkHelperUp.Install(n3));

    InetSocketAddress socketAddressUp = InetSocketAddress(n3Interface.GetAddress(0), port);
    OnOffHelper onOffHelperUp("ns3::TcpSocketFactory", Address());
    onOffHelperUp.SetAttribute("Remote", AddressValue(socketAddressUp));
    onOffHelperUp.SetAttribute("OnTime", StringValue("ns3::ConstantRandomVariable[Constant=1]"));
    onOffHelperUp.SetAttribute("OffTime", StringValue("ns3::ConstantRandomVariable[Constant=0]"));
    onOffHelperUp.SetAttribute("PacketSize", UintegerValue(flowsPacketsSize));
    onOffHelperUp.SetAttribute("DataRate", StringValue(flowsDatarate));
    sourceApps.Add(onOffHelperUp.Install(n1));

    port = 8;
    // Configure and install download flow
    Address addDown(InetSocketAddress(Ipv4Address::GetAny(), port));
    PacketSinkHelper sinkHelperDown("ns3::TcpSocketFactory", addDown);
    sinkHelperDown.SetAttribute("Protocol", TypeIdValue(TcpSocketFactory::GetTypeId()));
    downloadApp.Add(sinkHelperDown.Install(n1));

    InetSocketAddress socketAddressDown = InetSocketAddress(n1Interface.GetAddress(0), port);
    OnOffHelper onOffHelperDown("ns3::TcpSocketFactory", Address());
    onOffHelperDown.SetAttribute("Remote", AddressValue(socketAddressDown));
    onOffHelperDown.SetAttribute("OnTime", StringValue("ns3::ConstantRandomVariable[Constant=1]"));
    onOffHelperDown.SetAttribute("OffTime", StringValue("ns3::ConstantRandomVariable[Constant=0]"));
    onOffHelperDown.SetAttribute("PacketSize", UintegerValue(flowsPacketsSize));
    onOffHelperDown.SetAttribute("DataRate", StringValue(flowsDatarate));
    sourceApps.Add(onOffHelperDown.Install(n3));

    // Configure and install ping
    PingHelper ping(n3Interface.GetAddress(0));
    ping.SetAttribute("VerboseMode", EnumValue(Ping::VerboseMode::QUIET));
    ping.Install(n1);

    Config::Connect("/NodeList/*/ApplicationList/*/$ns3::Ping/Rtt", MakeCallback(&PingRtt));

    uploadApp.Start(Seconds(0));
    uploadApp.Stop(Seconds(stopTime));
    downloadApp.Start(Seconds(0));
    downloadApp.Stop(Seconds(stopTime));

    sourceApps.Start(Seconds(0 + 0.1));
    sourceApps.Stop(Seconds(stopTime - 0.1));

    Ptr<OutputStreamWrapper> uploadGoodputStream =
        ascii.CreateFileStream(queueDiscType + "-upGoodput.txt");
    Simulator::Schedule(Seconds(samplingPeriod),
                        &GoodputSampling,
                        uploadApp,
                        uploadGoodputStream,
                        samplingPeriod);
    Ptr<OutputStreamWrapper> downloadGoodputStream =
        ascii.CreateFileStream(queueDiscType + "-downGoodput.txt");
    Simulator::Schedule(Seconds(samplingPeriod),
                        &GoodputSampling,
                        downloadApp,
                        downloadGoodputStream,
                        samplingPeriod);

    // Flow monitor
    Ptr<FlowMonitor> flowMonitor;
    FlowMonitorHelper flowHelper;
    flowMonitor = flowHelper.InstallAll();

    accessLink.EnablePcapAll("queue");

    Simulator::Stop(Seconds(stopTime));
    Simulator::Run();

    flowMonitor->SerializeToXmlFile(queueDiscType + "-flowMonitor.xml", true, true);

    Simulator::Destroy();
    return 0;
}