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

#include "ns3/boolean.h"
#include "ns3/icmpv6-l4-protocol.h"
#include "ns3/inet6-socket-address.h"
#include "ns3/internet-stack-helper.h"
#include "ns3/ipv6-address-helper.h"
#include "ns3/ipv6-l3-protocol.h"
#include "ns3/ipv6-routing-helper.h"
#include "ns3/ipv6-static-routing.h"
#include "ns3/log.h"
#include "ns3/node.h"
#include "ns3/simple-channel.h"
#include "ns3/simple-net-device-helper.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/udp-l4-protocol.h"
#include "ns3/udp-socket-factory.h"

#include <limits>
#include <string>

using namespace ns3;

/**
 * @ingroup internet-test
 *
 * @brief IPv6 Forwarding Test
 */
class Ipv6ForwardingTest : 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;
    Ipv6ForwardingTest();

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

Ipv6ForwardingTest::Ipv6ForwardingTest()
    : TestCase("IPv6 forwarding")
{
}

void
Ipv6ForwardingTest::ReceivePkt(Ptr<Socket> socket)
{
    uint32_t availableData [[maybe_unused]] = 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
Ipv6ForwardingTest::DoSendData(Ptr<Socket> socket, std::string to)
{
    Address realTo = Inet6SocketAddress(Ipv6Address(to.c_str()), 1234);
    NS_TEST_EXPECT_MSG_EQ(socket->SendTo(Create<Packet>(123), 0, realTo), 123, "100");
}

void
Ipv6ForwardingTest::SendData(Ptr<Socket> socket, std::string to)
{
    m_receivedPacket = Create<Packet>();
    Simulator::ScheduleWithContext(socket->GetNode()->GetId(),
                                   Seconds(0),
                                   &Ipv6ForwardingTest::DoSendData,
                                   this,
                                   socket,
                                   to);
    Simulator::Run();
}

void
Ipv6ForwardingTest::DoRun()
{
    // Create topology

    // Receiver Node
    Ptr<Node> rxNode = CreateObject<Node>();
    // Forwarding Node
    Ptr<Node> fwNode = CreateObject<Node>();
    // Sender Node
    Ptr<Node> txNode = CreateObject<Node>();

    NodeContainer net1nodes(rxNode, fwNode);
    NodeContainer net2nodes(fwNode, txNode);
    NodeContainer nodes(rxNode, fwNode, txNode);

    SimpleNetDeviceHelper helperChannel1;
    helperChannel1.SetNetDevicePointToPointMode(true);
    NetDeviceContainer net1 = helperChannel1.Install(net1nodes);

    SimpleNetDeviceHelper helperChannel2;
    helperChannel2.SetNetDevicePointToPointMode(true);
    NetDeviceContainer net2 = helperChannel2.Install(net2nodes);

    InternetStackHelper internetv6;
    internetv6.Install(nodes);

    txNode->GetObject<Icmpv6L4Protocol>()->SetAttribute("DAD", BooleanValue(false));
    fwNode->GetObject<Icmpv6L4Protocol>()->SetAttribute("DAD", BooleanValue(false));
    rxNode->GetObject<Icmpv6L4Protocol>()->SetAttribute("DAD", BooleanValue(false));

    Ipv6AddressHelper ipv6helper;
    Ipv6InterfaceContainer iic1 = ipv6helper.AssignWithoutAddress(net1);
    Ipv6InterfaceContainer iic2 = ipv6helper.AssignWithoutAddress(net2);

    Ptr<NetDevice> device;
    Ptr<Ipv6> ipv6;
    int32_t ifIndex;
    Ipv6InterfaceAddress ipv6Addr;

    ipv6 = rxNode->GetObject<Ipv6>();
    device = net1.Get(0);
    ifIndex = ipv6->GetInterfaceForDevice(device);
    ipv6Addr = Ipv6InterfaceAddress(Ipv6Address("2001:1::2"), Ipv6Prefix(64));
    ipv6->AddAddress(ifIndex, ipv6Addr);

    ipv6 = fwNode->GetObject<Ipv6>();
    device = net1.Get(1);
    ifIndex = ipv6->GetInterfaceForDevice(device);
    ipv6Addr = Ipv6InterfaceAddress(Ipv6Address("2001:1::1"), Ipv6Prefix(64));
    ipv6->AddAddress(ifIndex, ipv6Addr);

    device = net2.Get(0);
    ifIndex = ipv6->GetInterfaceForDevice(device);
    ipv6Addr = Ipv6InterfaceAddress(Ipv6Address("2001:2::1"), Ipv6Prefix(64));
    ipv6->AddAddress(ifIndex, ipv6Addr);

    ipv6 = txNode->GetObject<Ipv6>();
    device = net2.Get(1);
    ifIndex = ipv6->GetInterfaceForDevice(device);
    ipv6Addr = Ipv6InterfaceAddress(Ipv6Address("2001:2::2"), Ipv6Prefix(64));
    ipv6->AddAddress(ifIndex, ipv6Addr);

    // Setup at least a route from the sender.
    Ptr<Ipv6StaticRouting> ipv6StaticRouting = Ipv6RoutingHelper::GetRouting<Ipv6StaticRouting>(
        txNode->GetObject<Ipv6>()->GetRoutingProtocol());
    ipv6StaticRouting->SetDefaultRoute(Ipv6Address("2001:2::1"), ifIndex);

    // Create the UDP sockets
    Ptr<SocketFactory> rxSocketFactory = rxNode->GetObject<UdpSocketFactory>();
    Ptr<Socket> rxSocket = rxSocketFactory->CreateSocket();
    NS_TEST_EXPECT_MSG_EQ(rxSocket->Bind(Inet6SocketAddress(Ipv6Address("2001:1::2"), 1234)),
                          0,
                          "trivial");
    rxSocket->SetRecvCallback(MakeCallback(&Ipv6ForwardingTest::ReceivePkt, this));

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

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

    // Unicast test
    SendData(txSocket, "2001:1::2");
    NS_TEST_EXPECT_MSG_EQ(m_receivedPacket->GetSize(), 0, "IPv6 Forwarding off");

    m_receivedPacket->RemoveAllByteTags();
    m_receivedPacket = nullptr;

    ipv6 = fwNode->GetObject<Ipv6>();
    ipv6->SetAttribute("IpForward", BooleanValue(true));
    SendData(txSocket, "2001:1::2");
    NS_TEST_EXPECT_MSG_EQ(m_receivedPacket->GetSize(), 123, "IPv6 Forwarding on");

    m_receivedPacket->RemoveAllByteTags();

    Simulator::Destroy();
}

/**
 * @ingroup internet-test
 *
 * @brief IPv6 Forwarding TestSuite
 */
class Ipv6ForwardingTestSuite : public TestSuite
{
  public:
    Ipv6ForwardingTestSuite()
        : TestSuite("ipv6-forwarding", Type::UNIT)
    {
        AddTestCase(new Ipv6ForwardingTest, TestCase::Duration::QUICK);
    }
};

static Ipv6ForwardingTestSuite
    g_ipv6forwardingTestSuite; //!< Static variable for test initialization
