/*
 * Copyright (c) 2017 Alexander Krotov
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Alexander Krotov <krotov@iitp.ru>
 *
 */

#include "lte-test-primary-cell-change.h"

#include "ns3/boolean.h"
#include "ns3/double.h"
#include "ns3/friis-spectrum-propagation-loss.h"
#include "ns3/integer.h"
#include "ns3/internet-stack-helper.h"
#include "ns3/ipv4-address-helper.h"
#include "ns3/ipv4-interface-container.h"
#include "ns3/ipv4-static-routing-helper.h"
#include "ns3/log.h"
#include "ns3/lte-enb-net-device.h"
#include "ns3/lte-helper.h"
#include "ns3/lte-ue-net-device.h"
#include "ns3/lte-ue-rrc.h"
#include "ns3/mobility-helper.h"
#include "ns3/net-device-container.h"
#include "ns3/node-container.h"
#include "ns3/point-to-point-epc-helper.h"
#include "ns3/point-to-point-helper.h"
#include "ns3/simulator.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE("LtePrimaryCellChangeTest");

/*
 * Test Suite
 */

LtePrimaryCellChangeTestSuite::LtePrimaryCellChangeTestSuite()
    : TestSuite("lte-primary-cell-change", Type::SYSTEM)
{
    // Test that handover from eNB to eNB with one carrier works within this framework.
    AddTestCase(new LtePrimaryCellChangeTestCase("ideal RRC, RngRun=1", true, 1, 1, 0, 1),
                TestCase::Duration::QUICK);
    AddTestCase(new LtePrimaryCellChangeTestCase("real RRC, RngRun=1", false, 1, 1, 0, 1),
                TestCase::Duration::QUICK);

    // Test that handover between first carriers of eNBs works.
    AddTestCase(new LtePrimaryCellChangeTestCase("ideal RRC, RngRun=1", true, 1, 2, 0, 2),
                TestCase::Duration::QUICK);
    AddTestCase(new LtePrimaryCellChangeTestCase("real RRC, RngRun=1", false, 1, 2, 0, 2),
                TestCase::Duration::QUICK);

    // Test that handover from second carrier of first eNB to first carrier of second eNB works.
    AddTestCase(new LtePrimaryCellChangeTestCase("ideal RRC, RngRun=1", true, 1, 2, 1, 2),
                TestCase::Duration::QUICK);
    AddTestCase(new LtePrimaryCellChangeTestCase("real RRC, RngRun=1", false, 1, 2, 1, 2),
                TestCase::Duration::QUICK);

    // Test that handover from first carrier of first eNB to first carrier of second eNB works.
    AddTestCase(new LtePrimaryCellChangeTestCase("ideal RRC, RngRun=1", true, 1, 2, 0, 3),
                TestCase::Duration::QUICK);
    AddTestCase(new LtePrimaryCellChangeTestCase("real RRC, RngRun=1", false, 1, 2, 0, 3),
                TestCase::Duration::QUICK);

    // Test that handover from second carrier of first eNB to second carrier of second eNB works.
    AddTestCase(new LtePrimaryCellChangeTestCase("ideal RRC, RngRun=1", true, 1, 2, 1, 3),
                TestCase::Duration::QUICK);
    AddTestCase(new LtePrimaryCellChangeTestCase("real RRC, RngRun=1", false, 1, 2, 1, 3),
                TestCase::Duration::QUICK);

    // Test intra-eNB inter-frequency handover.
    AddTestCase(new LtePrimaryCellChangeTestCase("ideal RRC, RngRun=1", true, 1, 2, 0, 1),
                TestCase::Duration::QUICK);
    AddTestCase(new LtePrimaryCellChangeTestCase("real RRC, RngRun=1", false, 1, 2, 0, 1),
                TestCase::Duration::QUICK);
    AddTestCase(new LtePrimaryCellChangeTestCase("ideal RRC, RngRun=1", true, 1, 2, 1, 0),
                TestCase::Duration::QUICK);
    AddTestCase(new LtePrimaryCellChangeTestCase("real RRC, RngRun=1", false, 1, 2, 1, 0),
                TestCase::Duration::QUICK);
    AddTestCase(new LtePrimaryCellChangeTestCase("ideal RRC, RngRun=1", true, 1, 4, 3, 1),
                TestCase::Duration::QUICK);
    AddTestCase(new LtePrimaryCellChangeTestCase("real RRC, RngRun=1", false, 1, 4, 3, 1),
                TestCase::Duration::QUICK);
} // end of LtePrimaryCellChangeTestSuite::LtePrimaryCellChangeTestSuite ()

/**
 * @ingroup lte-test
 * Static variable for test initialization
 */
static LtePrimaryCellChangeTestSuite g_ltePrimaryCellChangeTestSuite;

/*
 * Test Case
 */

LtePrimaryCellChangeTestCase::LtePrimaryCellChangeTestCase(std::string name,
                                                           bool isIdealRrc,
                                                           int64_t rngRun,
                                                           uint8_t numberOfComponentCarriers,
                                                           uint8_t sourceComponentCarrier,
                                                           uint8_t targetComponentCarrier)
    : TestCase(name),
      m_isIdealRrc{isIdealRrc},
      m_rngRun{rngRun},
      m_numberOfComponentCarriers{numberOfComponentCarriers},
      m_sourceComponentCarrier{sourceComponentCarrier},
      m_targetComponentCarrier{targetComponentCarrier}
{
    NS_LOG_FUNCTION(this << GetName());
}

LtePrimaryCellChangeTestCase::~LtePrimaryCellChangeTestCase()
{
    NS_LOG_FUNCTION(this << GetName());
}

void
LtePrimaryCellChangeTestCase::DoRun()
{
    NS_LOG_FUNCTION(this << GetName());

    Config::SetGlobal("RngRun", UintegerValue(m_rngRun));

    Config::SetDefault("ns3::LteEnbNetDevice::DlEarfcn", UintegerValue(100));
    Config::SetDefault("ns3::LteEnbNetDevice::UlEarfcn", UintegerValue(100 + 18000));
    Config::SetDefault("ns3::LteEnbNetDevice::DlBandwidth", UintegerValue(25));
    Config::SetDefault("ns3::LteEnbNetDevice::UlBandwidth", UintegerValue(25));
    Config::SetDefault("ns3::LteUeNetDevice::DlEarfcn", UintegerValue(100));

    // Create helpers.
    auto lteHelper = CreateObject<LteHelper>();
    lteHelper->SetAttribute("PathlossModel",
                            TypeIdValue(ns3::FriisSpectrumPropagationLossModel::GetTypeId()));
    lteHelper->SetAttribute("UseIdealRrc", BooleanValue(m_isIdealRrc));
    lteHelper->SetAttribute("NumberOfComponentCarriers",
                            UintegerValue(m_numberOfComponentCarriers));

    auto epcHelper = CreateObject<PointToPointEpcHelper>();
    lteHelper->SetEpcHelper(epcHelper);

    // Create nodes.
    NodeContainer enbNodes;
    enbNodes.Create(2);
    auto ueNode = CreateObject<Node>();

    MobilityHelper mobility;
    mobility.SetMobilityModel("ns3::ConstantPositionMobilityModel");
    mobility.Install(enbNodes);
    mobility.Install(ueNode);

    // Physical layer.
    auto enbDevs = lteHelper->InstallEnbDevice(enbNodes);
    auto ueDev = DynamicCast<LteUeNetDevice>(lteHelper->InstallUeDevice(ueNode).Get(0));

    auto sourceEnbDev = DynamicCast<LteEnbNetDevice>(
        enbDevs.Get(m_sourceComponentCarrier / m_numberOfComponentCarriers));
    auto targetEnbDev = DynamicCast<LteEnbNetDevice>(
        enbDevs.Get(m_targetComponentCarrier / m_numberOfComponentCarriers));

    // Network layer.
    InternetStackHelper internet;
    internet.Install(ueNode);
    epcHelper->AssignUeIpv4Address(NetDeviceContainer(ueDev));

    std::map<uint8_t, Ptr<ComponentCarrierUe>> ueCcMap = ueDev->GetCcMap();
    ueDev->SetDlEarfcn(ueCcMap.at(m_sourceComponentCarrier)->GetDlEarfcn());

    // Attach UE to specified component carrier
    lteHelper->Attach(ueDev, sourceEnbDev, m_sourceComponentCarrier % m_numberOfComponentCarriers);

    // Connect to trace sources in UEs
    Config::Connect("/NodeList/*/DeviceList/*/LteUeRrc/StateTransition",
                    MakeCallback(&LtePrimaryCellChangeTestCase::StateTransitionCallback, this));
    Config::Connect(
        "/NodeList/*/DeviceList/*/LteUeRrc/ConnectionEstablished",
        MakeCallback(&LtePrimaryCellChangeTestCase::ConnectionEstablishedCallback, this));

    uint16_t targetCellId = targetEnbDev->GetCcMap()
                                .at(m_targetComponentCarrier % m_numberOfComponentCarriers)
                                ->GetCellId();

    lteHelper->AddX2Interface(enbNodes);
    lteHelper->HandoverRequest(Seconds(1), ueDev, sourceEnbDev, targetCellId);

    // Run simulation.
    Simulator::Stop(Seconds(2));
    Simulator::Run();

    uint16_t expectedCellId = targetCellId;
    uint16_t actualCellId = ueDev->GetRrc()->GetCellId();
    NS_TEST_ASSERT_MSG_EQ(expectedCellId,
                          actualCellId,
                          "IMSI " << ueDev->GetImsi() << " has attached to an unexpected cell");

    NS_TEST_ASSERT_MSG_EQ(m_lastState.at(ueDev->GetImsi()),
                          LteUeRrc::CONNECTED_NORMALLY,
                          "UE " << ueDev->GetImsi() << " is not at CONNECTED_NORMALLY state");

    // Destroy simulator.
    Simulator::Destroy();
}

void
LtePrimaryCellChangeTestCase::StateTransitionCallback(std::string context,
                                                      uint64_t imsi,
                                                      uint16_t cellId,
                                                      uint16_t rnti,
                                                      LteUeRrc::State oldState,
                                                      LteUeRrc::State newState)
{
    NS_LOG_FUNCTION(this << imsi << cellId << rnti << oldState << newState);
    m_lastState[imsi] = newState;
}

void
LtePrimaryCellChangeTestCase::ConnectionEstablishedCallback(std::string context,
                                                            uint64_t imsi,
                                                            uint16_t cellId,
                                                            uint16_t rnti)
{
    NS_LOG_FUNCTION(this << imsi << cellId << rnti);
}
