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

// Adaptation of examples/udp/udp-client-server.cc for
// Click based nodes running wifi.
//
// Network topology:
//
//               (1.4)
//             (( n4 ))
//
//          172.16.1.0/24
//
//   (1.1)      (1.2)       (1.3)
//     n0 ))   (( n1 ))   (( n2
//               WLAN
//
// - UDP flows from n0 to n1 and n2 to n1.
// - All nodes are Click based.
// - The single ethernet interface that each node
//   uses is named 'eth0' in the Click file.
// - Node 4 is running in promiscuous mode and can listen in on
//   the packets being exchanged between n0-n1 and n2-n1.
//

#include "ns3/applications-module.h"
#include "ns3/click-internet-stack-helper.h"
#include "ns3/core-module.h"
#include "ns3/internet-module.h"
#include "ns3/ipv4-click-routing.h"
#include "ns3/mobility-module.h"
#include "ns3/network-module.h"
#include "ns3/wifi-module.h"

#include <fstream>

using namespace ns3;

NS_LOG_COMPONENT_DEFINE("NsclickUdpClientServerWifi");

void
ReadArp(Ptr<Ipv4ClickRouting> clickRouter)
{
    // Access the handlers
    NS_LOG_INFO(clickRouter->ReadHandler("wifi/arpquerier", "table"));
    NS_LOG_INFO(clickRouter->ReadHandler("wifi/arpquerier", "stats"));
}

void
WriteArp(Ptr<Ipv4ClickRouting> clickRouter)
{
    // Access the handler
    NS_LOG_INFO(
        clickRouter->WriteHandler("wifi/arpquerier", "insert", "172.16.1.2 00:00:00:00:00:02"));
}

int
main(int argc, char* argv[])
{
    std::string clickConfigFolder = "src/click/examples";

    CommandLine cmd(__FILE__);
    cmd.AddValue("clickConfigFolder",
                 "Base folder for click configuration files",
                 clickConfigFolder);
    cmd.Parse(argc, argv);

    //
    // Enable logging
    //
    LogComponentEnable("NsclickUdpClientServerWifi", LOG_LEVEL_INFO);

    //
    // Explicitly create the nodes required by the topology (shown above).
    //
    NS_LOG_INFO("Create nodes.");
    NodeContainer n;
    n.Create(4);

    NS_LOG_INFO("Create channels.");
    //
    // Explicitly create the channels required by the topology (shown above).
    //
    std::string phyMode("DsssRate1Mbps");

    // disable fragmentation for frames below 2200 bytes
    Config::SetDefault("ns3::WifiRemoteStationManager::FragmentationThreshold",
                       StringValue("2200"));
    // turn off RTS/CTS for frames below 2200 bytes
    Config::SetDefault("ns3::WifiRemoteStationManager::RtsCtsThreshold", StringValue("2200"));
    // Fix non-unicast data rate to be the same as that of unicast
    Config::SetDefault("ns3::WifiRemoteStationManager::NonUnicastMode", StringValue(phyMode));

    WifiHelper wifi;
    wifi.SetStandard(WIFI_STANDARD_80211b);

    YansWifiPhyHelper wifiPhy;
    // This is one parameter that matters when using FixedRssLossModel
    // set it to zero; otherwise, gain will be added
    wifiPhy.Set("RxGain", DoubleValue(0));
    // ns-3 supports RadioTap and Prism tracing extensions for 802.11b
    wifiPhy.SetPcapDataLinkType(WifiPhyHelper::DLT_IEEE802_11_RADIO);

    YansWifiChannelHelper wifiChannel;
    wifiChannel.SetPropagationDelay("ns3::ConstantSpeedPropagationDelayModel");
    // The below FixedRssLossModel will cause the rss to be fixed regardless
    // of the distance between the two stations, and the transmit power
    wifiChannel.AddPropagationLoss("ns3::FixedRssLossModel", "Rss", DoubleValue(-80));
    wifiPhy.SetChannel(wifiChannel.Create());

    // Add an upper mac and disable rate control
    WifiMacHelper wifiMac;
    wifi.SetRemoteStationManager("ns3::ConstantRateWifiManager",
                                 "DataMode",
                                 StringValue(phyMode),
                                 "ControlMode",
                                 StringValue(phyMode));
    // Set it to adhoc mode
    wifiMac.SetType("ns3::AdhocWifiMac");
    NetDeviceContainer d = wifi.Install(wifiPhy, wifiMac, n);

    MobilityHelper mobility;
    Ptr<ListPositionAllocator> positionAlloc = CreateObject<ListPositionAllocator>();
    positionAlloc->Add(Vector(0.0, 0.0, 0.0));
    positionAlloc->Add(Vector(10.0, 0.0, 0.0));
    positionAlloc->Add(Vector(20.0, 0.0, 0.0));
    positionAlloc->Add(Vector(0.0, 10.0, 0.0));
    mobility.SetPositionAllocator(positionAlloc);
    mobility.SetMobilityModel("ns3::ConstantPositionMobilityModel");
    mobility.Install(n);

    //
    // Install Click on the nodes
    //
    ClickInternetStackHelper clickinternet;
    clickinternet.SetClickFile(n.Get(0),
                               clickConfigFolder + "/nsclick-wifi-single-interface.click");
    clickinternet.SetClickFile(n.Get(1),
                               clickConfigFolder + "/nsclick-wifi-single-interface.click");
    clickinternet.SetClickFile(n.Get(2),
                               clickConfigFolder + "/nsclick-wifi-single-interface.click");

    // Node 4 is to run in promiscuous mode. This can be verified
    // from the pcap trace Node4_in_eth0.pcap generated after running
    // this script.
    clickinternet.SetClickFile(n.Get(3),
                               clickConfigFolder + "/nsclick-wifi-single-interface-promisc.click");
    clickinternet.SetRoutingTableElement(n, "rt");
    clickinternet.Install(n);
    Ipv4AddressHelper ipv4;
    //
    // We've got the "hardware" in place.  Now we need to add IP addresses.
    //
    NS_LOG_INFO("Assign IP Addresses.");
    ipv4.SetBase("172.16.1.0", "255.255.255.0");
    Ipv4InterfaceContainer i = ipv4.Assign(d);

    NS_LOG_INFO("Create Applications.");
    //
    // Create one udpServer applications on node one.
    //
    uint16_t port = 4000;
    UdpServerHelper server(port);
    ApplicationContainer apps = server.Install(n.Get(1));
    apps.Start(Seconds(1));
    apps.Stop(Seconds(10));

    //
    // Create one UdpClient application to send UDP datagrams from node zero to
    // node one.
    //
    uint32_t MaxPacketSize = 1024;
    Time interPacketInterval = Seconds(0.5);
    uint32_t maxPacketCount = 320;
    UdpClientHelper client(i.GetAddress(1), port);
    client.SetAttribute("MaxPackets", UintegerValue(maxPacketCount));
    client.SetAttribute("Interval", TimeValue(interPacketInterval));
    client.SetAttribute("PacketSize", UintegerValue(MaxPacketSize));
    apps = client.Install(NodeContainer(n.Get(0), n.Get(2)));
    apps.Start(Seconds(2));
    apps.Stop(Seconds(10));

    wifiPhy.EnablePcap("nsclick-udp-client-server-wifi", d);

    // Force the MAC address of the second node: The current ARP
    // implementation of Click sends only one ARP request per incoming
    // packet for an unknown destination and does not retransmit if no
    // response is received. With the scenario of this example, all ARP
    // requests of node 3 are lost due to interference from node
    // 1. Hence, we fill in the ARP table of node 2 before at the
    // beginning of the simulation
    Simulator::Schedule(Seconds(0.5), &ReadArp, n.Get(2)->GetObject<Ipv4ClickRouting>());
    Simulator::Schedule(Seconds(0.6), &WriteArp, n.Get(2)->GetObject<Ipv4ClickRouting>());
    Simulator::Schedule(Seconds(0.7), &ReadArp, n.Get(2)->GetObject<Ipv4ClickRouting>());

    //
    // Now, do the actual simulation.
    //
    NS_LOG_INFO("Run Simulation.");
    Simulator::Stop(Seconds(20));
    Simulator::Run();
    Simulator::Destroy();
    NS_LOG_INFO("Done.");

    return 0;
}
