/*
 * Copyright (c) 2013 Natale Patriciello <natale.patriciello@gmail.com>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#include "tcp-general-test.h"

#include "ns3/log.h"
#include "ns3/node.h"
#include "ns3/tcp-header.h"
#include "ns3/tcp-option-ts.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE("TimestampTestSuite");

/**
 * \ingroup internet-test
 *
 * \brief TCP TimeStamp enabling Test.
 */
class TimestampTestCase : public TcpGeneralTest
{
  public:
    /**
     * TimeStamp configuration.
     */
    enum Configuration
    {
        DISABLED,
        ENABLED_RECEIVER,
        ENABLED_SENDER,
        ENABLED
    };

    /**
     * \brief Constructor.
     * \param conf Test configuration.
     */
    TimestampTestCase(TimestampTestCase::Configuration conf);

  protected:
    Ptr<TcpSocketMsgBase> CreateReceiverSocket(Ptr<Node> node) override;
    Ptr<TcpSocketMsgBase> CreateSenderSocket(Ptr<Node> node) override;

    void Tx(const Ptr<const Packet> p, const TcpHeader& h, SocketWho who) override;
    void Rx(const Ptr<const Packet> p, const TcpHeader& h, SocketWho who) override;

    Configuration m_configuration; //!< Test configuration.
};

TimestampTestCase::TimestampTestCase(TimestampTestCase::Configuration conf)
    : TcpGeneralTest("Testing the TCP Timestamp option")
{
    m_configuration = conf;
}

Ptr<TcpSocketMsgBase>
TimestampTestCase::CreateReceiverSocket(Ptr<Node> node)
{
    Ptr<TcpSocketMsgBase> socket = TcpGeneralTest::CreateReceiverSocket(node);

    switch (m_configuration)
    {
    case DISABLED:
        socket->SetAttribute("Timestamp", BooleanValue(false));
        break;

    case ENABLED_RECEIVER:
        socket->SetAttribute("Timestamp", BooleanValue(true));
        break;

    case ENABLED_SENDER:
        socket->SetAttribute("Timestamp", BooleanValue(false));
        break;

    case ENABLED:
        socket->SetAttribute("Timestamp", BooleanValue(true));
        break;
    }

    return socket;
}

Ptr<TcpSocketMsgBase>
TimestampTestCase::CreateSenderSocket(Ptr<Node> node)
{
    Ptr<TcpSocketMsgBase> socket = TcpGeneralTest::CreateSenderSocket(node);

    switch (m_configuration)
    {
    case DISABLED:
    case ENABLED_RECEIVER:
        socket->SetAttribute("Timestamp", BooleanValue(false));
        break;

    case ENABLED_SENDER:
    case ENABLED:
        socket->SetAttribute("Timestamp", BooleanValue(true));
        break;
    }

    return socket;
}

void
TimestampTestCase::Tx(const Ptr<const Packet> p, const TcpHeader& h, SocketWho who)
{
    if (m_configuration == DISABLED)
    {
        NS_TEST_ASSERT_MSG_EQ(h.HasOption(TcpOption::TS),
                              false,
                              "timestamp disabled but option enabled");
    }
    else if (m_configuration == ENABLED)
    {
        NS_TEST_ASSERT_MSG_EQ(h.HasOption(TcpOption::TS),
                              true,
                              "timestamp enabled but option disabled");
    }

    NS_LOG_INFO(h);
    if (who == SENDER)
    {
        if (h.GetFlags() & TcpHeader::SYN)
        {
            if (m_configuration == ENABLED_RECEIVER)
            {
                NS_TEST_ASSERT_MSG_EQ(h.HasOption(TcpOption::TS),
                                      false,
                                      "timestamp disabled but option enabled");
            }
            else if (m_configuration == ENABLED_SENDER)
            {
                NS_TEST_ASSERT_MSG_EQ(h.HasOption(TcpOption::TS),
                                      true,
                                      "timestamp enabled but option disabled");
            }
        }
        else
        {
            if (m_configuration != ENABLED)
            {
                NS_TEST_ASSERT_MSG_EQ(h.HasOption(TcpOption::TS),
                                      false,
                                      "timestamp disabled but option enabled");
            }
        }
    }
    else if (who == RECEIVER)
    {
        if (h.GetFlags() & TcpHeader::SYN)
        {
            // Sender has not sent timestamp, so implementation should disable ts
            if (m_configuration == ENABLED_RECEIVER)
            {
                NS_TEST_ASSERT_MSG_EQ(h.HasOption(TcpOption::TS),
                                      false,
                                      "sender has not ts, but receiver sent anyway");
            }
            else if (m_configuration == ENABLED_SENDER)
            {
                NS_TEST_ASSERT_MSG_EQ(h.HasOption(TcpOption::TS),
                                      false,
                                      "receiver has not ts enabled but sent anyway");
            }
        }
        else
        {
            if (m_configuration != ENABLED)
            {
                NS_TEST_ASSERT_MSG_EQ(h.HasOption(TcpOption::TS),
                                      false,
                                      "timestamp disabled but option enabled");
            }
        }
    }
}

void
TimestampTestCase::Rx(const Ptr<const Packet> p, const TcpHeader& h, SocketWho who)
{
    // if (who == SENDER)
    // {
    // }
    // else if (who == RECEIVER)
    // {
    // }
}

/**
 * \ingroup internet-test
 *
 * \brief TCP TimeStamp values Test.
 */
class TimestampValueTestCase : public TestCase
{
  public:
    /**
     * \brief Constructor.
     * \param startTime Start time (Seconds).
     * \param timeToWait Time to wait (Seconds).
     * \param name Test description.
     */
    TimestampValueTestCase(double startTime, double timeToWait, std::string name);

  private:
    void DoRun() override;
    void DoTeardown() override;

    /**
     * \brief Perform the test checks.
     */
    void Check();
    /**
     * \brief Test initialization.
     */
    void Init();

    double m_startTime;  //!< Start time (Seconds).
    double m_timeToWait; //!< Time to wait (Seconds).
    double m_initValue;  //!< Initialization value (Seconds).
};

TimestampValueTestCase::TimestampValueTestCase(double startTime,
                                               double timeToWait,
                                               std::string name)
    : TestCase(name)
{
    m_startTime = startTime;
    m_timeToWait = timeToWait;
}

void
TimestampValueTestCase::DoRun()
{
    Simulator::Schedule(Seconds(m_startTime + m_timeToWait), &TimestampValueTestCase::Check, this);
    Simulator::Schedule(Seconds(m_startTime), &TimestampValueTestCase::Init, this);

    Simulator::Run();
}

void
TimestampValueTestCase::DoTeardown()
{
    Simulator::Destroy();
}

void
TimestampValueTestCase::Init()
{
    m_initValue = TcpOptionTS::NowToTsValue();
}

void
TimestampValueTestCase::Check()
{
    uint32_t lastValue = TcpOptionTS::NowToTsValue();

    NS_TEST_ASSERT_MSG_EQ_TOL(MilliSeconds(lastValue - m_initValue),
                              Seconds(m_timeToWait),
                              MilliSeconds(1),
                              "Different TS values");

    NS_TEST_ASSERT_MSG_EQ_TOL(TcpOptionTS::ElapsedTimeFromTsValue(m_initValue),
                              Seconds(m_timeToWait),
                              MilliSeconds(1),
                              "Estimating Wrong RTT");
}

/**
 * \ingroup internet-test
 *
 * \brief TCP TimeStamp TestSuite.
 */
class TcpTimestampTestSuite : public TestSuite
{
  public:
    TcpTimestampTestSuite()
        : TestSuite("tcp-timestamp", Type::UNIT)
    {
        AddTestCase(new TimestampTestCase(TimestampTestCase::DISABLED), TestCase::Duration::QUICK);
        AddTestCase(new TimestampTestCase(TimestampTestCase::ENABLED_RECEIVER),
                    TestCase::Duration::QUICK);
        AddTestCase(new TimestampTestCase(TimestampTestCase::ENABLED_SENDER),
                    TestCase::Duration::QUICK);
        AddTestCase(new TimestampTestCase(TimestampTestCase::ENABLED), TestCase::Duration::QUICK);
        AddTestCase(new TimestampValueTestCase(0.0, 0.01, "Value Check"),
                    TestCase::Duration::QUICK);
        AddTestCase(new TimestampValueTestCase(3.0, 0.5, "Value Check"), TestCase::Duration::QUICK);
        AddTestCase(new TimestampValueTestCase(5.5, 1.0, "Value Check"), TestCase::Duration::QUICK);
        AddTestCase(new TimestampValueTestCase(6.0, 2.0, "Value Check"), TestCase::Duration::QUICK);
        AddTestCase(new TimestampValueTestCase(2.4, 0.7, "Value Check"), TestCase::Duration::QUICK);
    }
};

static TcpTimestampTestSuite g_tcpTimestampTestSuite; //!< Static variable for test initialization
