/*
 * Copyright (c) 2013 Universita' di Firenze
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Tommaso Pecorella <tommaso.pecorella@unifi.it>
 */

#include "ns3/arp-l3-protocol.h"
#include "ns3/boolean.h"
#include "ns3/icmpv4-l4-protocol.h"
#include "ns3/inet-socket-address.h"
#include "ns3/internet-stack-helper.h"
#include "ns3/ipv4-l3-protocol.h"
#include "ns3/ipv4-routing-helper.h"
#include "ns3/ipv4-static-routing.h"
#include "ns3/log.h"
#include "ns3/node.h"
#include "ns3/simple-channel.h"
#include "ns3/simple-net-device.h"
#include "ns3/simulator.h"
#include "ns3/socket-factory.h"
#include "ns3/socket.h"
#include "ns3/test.h"
#include "ns3/traffic-control-layer.h"
#include "ns3/udp-l4-protocol.h"
#include "ns3/udp-socket-factory.h"

#include <limits>
#include <string>

using namespace ns3;

/**
 * @ingroup internet-test
 *
 * @brief IPv4 Forwarding Test
 */
class Ipv4ForwardingTest : public TestCase
{
    Ptr<Packet> m_receivedPacket; //!< Received packet

    /**
     * @brief Send data.
     * @param socket The sending socket.
     * @param to Destination address.
     */
    void DoSendData(Ptr<Socket> socket, std::string to);
    /**
     * @brief Send data.
     * @param socket The sending socket.
     * @param to Destination address.
     */
    void SendData(Ptr<Socket> socket, std::string to);

  public:
    void DoRun() override;
    Ipv4ForwardingTest();

    /**
     * @brief Receive data.
     * @param socket The receiving socket.
     */
    void ReceivePkt(Ptr<Socket> socket);
};

Ipv4ForwardingTest::Ipv4ForwardingTest()
    : TestCase("UDP socket implementation")
{
}

void
Ipv4ForwardingTest::ReceivePkt(Ptr<Socket> socket)
{
    uint32_t availableData;
    availableData = socket->GetRxAvailable();
    m_receivedPacket = socket->Recv(std::numeric_limits<uint32_t>::max(), 0);
    NS_TEST_ASSERT_MSG_EQ(availableData,
                          m_receivedPacket->GetSize(),
                          "Received packet size is not equal to Rx buffer size");
}

void
Ipv4ForwardingTest::DoSendData(Ptr<Socket> socket, std::string to)
{
    Address realTo = InetSocketAddress(Ipv4Address(to.c_str()), 1234);
    NS_TEST_EXPECT_MSG_EQ(socket->SendTo(Create<Packet>(123), 0, realTo), 123, "100");
}

void
Ipv4ForwardingTest::SendData(Ptr<Socket> socket, std::string to)
{
    m_receivedPacket = Create<Packet>();
    Simulator::ScheduleWithContext(socket->GetNode()->GetId(),
                                   Seconds(0),
                                   &Ipv4ForwardingTest::DoSendData,
                                   this,
                                   socket,
                                   to);
    Simulator::Run();
}

void
Ipv4ForwardingTest::DoRun()
{
    // Create topology

    // Receiver Node
    Ptr<Node> rxNode = CreateObject<Node>();

    InternetStackHelper internet;
    internet.SetIpv6StackInstall(false);

    internet.Install(rxNode);
    Ptr<SimpleNetDevice> rxDev;
    { // first interface
        rxDev = CreateObject<SimpleNetDevice>();
        rxDev->SetAddress(Mac48Address::ConvertFrom(Mac48Address::Allocate()));
        rxNode->AddDevice(rxDev);
        Ptr<Ipv4> ipv4 = rxNode->GetObject<Ipv4>();
        uint32_t netdev_idx = ipv4->AddInterface(rxDev);
        Ipv4InterfaceAddress ipv4Addr =
            Ipv4InterfaceAddress(Ipv4Address("10.0.0.2"), Ipv4Mask(0xffff0000U));
        ipv4->AddAddress(netdev_idx, ipv4Addr);
        ipv4->SetUp(netdev_idx);
    }

    // Forwarding Node
    Ptr<Node> fwNode = CreateObject<Node>();

    internet.Install(fwNode);
    Ptr<SimpleNetDevice> fwDev1;
    Ptr<SimpleNetDevice> fwDev2;
    { // first interface
        fwDev1 = CreateObject<SimpleNetDevice>();
        fwDev1->SetAddress(Mac48Address::ConvertFrom(Mac48Address::Allocate()));
        fwNode->AddDevice(fwDev1);
        Ptr<Ipv4> ipv4 = fwNode->GetObject<Ipv4>();
        uint32_t netdev_idx = ipv4->AddInterface(fwDev1);
        Ipv4InterfaceAddress ipv4Addr =
            Ipv4InterfaceAddress(Ipv4Address("10.0.0.1"), Ipv4Mask(0xffff0000U));
        ipv4->AddAddress(netdev_idx, ipv4Addr);
        ipv4->SetUp(netdev_idx);
    }

    { // second interface
        fwDev2 = CreateObject<SimpleNetDevice>();
        fwDev2->SetAddress(Mac48Address::ConvertFrom(Mac48Address::Allocate()));
        fwNode->AddDevice(fwDev2);
        Ptr<Ipv4> ipv4 = fwNode->GetObject<Ipv4>();
        uint32_t netdev_idx = ipv4->AddInterface(fwDev2);
        Ipv4InterfaceAddress ipv4Addr =
            Ipv4InterfaceAddress(Ipv4Address("10.1.0.1"), Ipv4Mask(0xffff0000U));
        ipv4->AddAddress(netdev_idx, ipv4Addr);
        ipv4->SetUp(netdev_idx);
    }

    // Sender Node
    Ptr<Node> txNode = CreateObject<Node>();

    internet.Install(txNode);
    Ptr<SimpleNetDevice> txDev;
    {
        txDev = CreateObject<SimpleNetDevice>();
        txDev->SetAddress(Mac48Address::ConvertFrom(Mac48Address::Allocate()));
        txNode->AddDevice(txDev);
        Ptr<Ipv4> ipv4 = txNode->GetObject<Ipv4>();
        uint32_t netdev_idx = ipv4->AddInterface(txDev);
        Ipv4InterfaceAddress ipv4Addr =
            Ipv4InterfaceAddress(Ipv4Address("10.1.0.2"), Ipv4Mask(0xffff0000U));
        ipv4->AddAddress(netdev_idx, ipv4Addr);
        ipv4->SetUp(netdev_idx);
        Ptr<Ipv4StaticRouting> ipv4StaticRouting = Ipv4RoutingHelper::GetRouting<Ipv4StaticRouting>(
            txNode->GetObject<Ipv4>()->GetRoutingProtocol());
        ipv4StaticRouting->SetDefaultRoute(Ipv4Address("10.1.0.1"), netdev_idx);
    }

    // link the two nodes
    Ptr<SimpleChannel> channel1 = CreateObject<SimpleChannel>();
    rxDev->SetChannel(channel1);
    fwDev1->SetChannel(channel1);

    Ptr<SimpleChannel> channel2 = CreateObject<SimpleChannel>();
    fwDev2->SetChannel(channel2);
    txDev->SetChannel(channel2);

    // Create the UDP sockets
    Ptr<SocketFactory> rxSocketFactory = rxNode->GetObject<UdpSocketFactory>();
    Ptr<Socket> rxSocket = rxSocketFactory->CreateSocket();
    NS_TEST_EXPECT_MSG_EQ(rxSocket->Bind(InetSocketAddress(Ipv4Address("10.0.0.2"), 1234)),
                          0,
                          "trivial");
    rxSocket->SetRecvCallback(MakeCallback(&Ipv4ForwardingTest::ReceivePkt, this));

    Ptr<SocketFactory> txSocketFactory = txNode->GetObject<UdpSocketFactory>();
    Ptr<Socket> txSocket = txSocketFactory->CreateSocket();
    txSocket->SetAllowBroadcast(true);

    // ------ Now the tests ------------

    // Unicast test
    SendData(txSocket, "10.0.0.2");
    NS_TEST_EXPECT_MSG_EQ(m_receivedPacket->GetSize(), 123, "IPv4 Forwarding on");

    m_receivedPacket->RemoveAllByteTags();
    m_receivedPacket = nullptr;

    Ptr<Ipv4> ipv4 = fwNode->GetObject<Ipv4>();
    ipv4->SetAttribute("IpForward", BooleanValue(false));
    SendData(txSocket, "10.0.0.2");
    NS_TEST_EXPECT_MSG_EQ(m_receivedPacket->GetSize(), 0, "IPv4 Forwarding off");

    Simulator::Destroy();
}

/**
 * @ingroup internet-test
 *
 * @brief IPv4 Forwarding TestSuite
 */
class Ipv4ForwardingTestSuite : public TestSuite
{
  public:
    Ipv4ForwardingTestSuite();

  private:
};

Ipv4ForwardingTestSuite::Ipv4ForwardingTestSuite()
    : TestSuite("ipv4-forwarding", Type::UNIT)
{
    AddTestCase(new Ipv4ForwardingTest, TestCase::Duration::QUICK);
}

static Ipv4ForwardingTestSuite
    g_ipv4forwardingTestSuite; //!< Static variable for test initialization
