/*
 * Copyright (c) 2009 MIRKO BANCHI
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Mirko Banchi <mk.banchi@gmail.com>
 */

/**
 * This is a simple example in order to show how 802.11n compressed block ack mechanism could be
 * used.
 *
 * Network topology:
 *
 *  Wifi 192.168.1.0
 *
 *        AP
 *   *    *
 *   |    |
 *   n1   n2
 *
 * In this example a QoS sta sends UDP datagram packets to access point. On the access point
 * there is no application installed so it replies to every packet with an ICMP frame. However
 * our attention is on originator sta n1. We have set blockAckThreshold (minimum number of packets
 * to use block ack) to 2 so if there are in the BestEffort queue more than 2 packets a block ack
 * will be negotiated. We also set a timeout for block ack inactivity to 3 blocks of 1024
 * microseconds. This timer is reset when:
 *    - the originator receives a block ack frame.
 *    - the recipient receives a block ack request or a MPDU with ack policy Block Ack.
 */

#include "ns3/boolean.h"
#include "ns3/command-line.h"
#include "ns3/double.h"
#include "ns3/internet-stack-helper.h"
#include "ns3/ipv4-address-helper.h"
#include "ns3/ipv4-global-routing-helper.h"
#include "ns3/log.h"
#include "ns3/mobility-helper.h"
#include "ns3/mobility-model.h"
#include "ns3/on-off-helper.h"
#include "ns3/rectangle.h"
#include "ns3/ssid.h"
#include "ns3/string.h"
#include "ns3/uinteger.h"
#include "ns3/yans-wifi-channel.h"
#include "ns3/yans-wifi-helper.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE("Test-block-ack");

int
main(int argc, char* argv[])
{
    CommandLine cmd(__FILE__);
    cmd.Parse(argc, argv);

    LogComponentEnable("QosTxop", LOG_LEVEL_DEBUG);
    LogComponentEnable("BlockAckManager", LOG_LEVEL_INFO);

    Ptr<Node> sta = CreateObject<Node>();
    Ptr<Node> ap = CreateObject<Node>();

    YansWifiChannelHelper channel = YansWifiChannelHelper::Default();
    YansWifiPhyHelper phy;
    phy.SetPcapDataLinkType(WifiPhyHelper::DLT_IEEE802_11_RADIO);
    phy.SetChannel(channel.Create());

    WifiHelper wifi;
    wifi.SetStandard(WIFI_STANDARD_80211n);
    WifiMacHelper mac;
    /* disable fragmentation */
    wifi.SetRemoteStationManager("ns3::IdealWifiManager",
                                 "FragmentationThreshold",
                                 UintegerValue(2500));

    Ssid ssid("My-network");

    mac.SetType("ns3::StaWifiMac",
                "QosSupported",
                BooleanValue(true),
                "Ssid",
                SsidValue(ssid),
                /* setting blockack threshold for sta's BE queue */
                "BE_BlockAckThreshold",
                UintegerValue(2),
                /* setting block inactivity timeout to 3*1024 = 3072 microseconds */
                "BE_BlockAckInactivityTimeout",
                UintegerValue(3));
    NetDeviceContainer staDevice = wifi.Install(phy, mac, sta);

    mac.SetType("ns3::ApWifiMac",
                "QosSupported",
                BooleanValue(true),
                "Ssid",
                SsidValue(ssid),
                "BE_BlockAckThreshold",
                UintegerValue(0));
    NetDeviceContainer apDevice = wifi.Install(phy, mac, ap);

    /* Setting mobility model */
    MobilityHelper mobility;

    mobility.SetPositionAllocator("ns3::GridPositionAllocator",
                                  "MinX",
                                  DoubleValue(0.0),
                                  "MinY",
                                  DoubleValue(0.0),
                                  "DeltaX",
                                  DoubleValue(5.0),
                                  "DeltaY",
                                  DoubleValue(10.0),
                                  "GridWidth",
                                  UintegerValue(3),
                                  "LayoutType",
                                  StringValue("RowFirst"));

    mobility.SetMobilityModel("ns3::RandomWalk2dMobilityModel",
                              "Bounds",
                              RectangleValue(Rectangle(-50, 50, -50, 50)));
    mobility.Install(sta);

    mobility.SetMobilityModel("ns3::ConstantPositionMobilityModel");
    mobility.Install(ap);

    /* Internet stack*/
    InternetStackHelper stack;
    stack.Install(sta);
    stack.Install(ap);

    Ipv4AddressHelper address;

    address.SetBase("192.168.1.0", "255.255.255.0");
    Ipv4InterfaceContainer staIf;
    Ipv4InterfaceContainer apIf;
    staIf = address.Assign(staDevice);
    apIf = address.Assign(apDevice);

    /* Setting applications */

    uint16_t port = 9;
    DataRate dataRate("1Mb/s");
    OnOffHelper onOff("ns3::UdpSocketFactory",
                      Address(InetSocketAddress(apIf.GetAddress(0), port)));
    onOff.SetAttribute("DataRate", DataRateValue(dataRate));
    onOff.SetAttribute("OnTime", StringValue("ns3::ConstantRandomVariable[Constant=0.01]"));
    onOff.SetAttribute("OffTime", StringValue("ns3::ConstantRandomVariable[Constant=8]"));
    onOff.SetAttribute("PacketSize", UintegerValue(50));

    ApplicationContainer staApps = onOff.Install(sta);

    staApps.Start(Seconds(1.0));
    staApps.Stop(Seconds(10.0));

    Ipv4GlobalRoutingHelper::PopulateRoutingTables();

    Simulator::Stop(Seconds(10.0));

    phy.EnablePcap("test-blockack", ap->GetId(), 0);
    Simulator::Run();
    Simulator::Destroy();

    return 0;
}
