/*
 * Copyright 2015-present Open Networking Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.opencord.aaa.impl;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.onlab.junit.TestUtils;
import org.onlab.packet.BasePacket;
import org.onlab.packet.DeserializationException;
import org.onlab.packet.EAP;
import org.onlab.packet.Ethernet;
import org.onlab.packet.IpAddress;
import org.onlab.packet.RADIUS;
import org.onlab.packet.RADIUSAttribute;
import org.onosproject.cluster.ClusterServiceAdapter;
import org.onosproject.core.ApplicationId;
import org.onosproject.core.CoreServiceAdapter;
import org.onosproject.event.DefaultEventSinkRegistry;
import org.onosproject.event.Event;
import org.onosproject.event.EventDeliveryService;
import org.onosproject.event.EventSink;
import org.onosproject.net.config.Config;
import org.onosproject.net.config.NetworkConfigRegistryAdapter;
import org.onosproject.net.packet.DefaultInboundPacket;
import org.onosproject.net.packet.InboundPacket;
import org.onosproject.net.packet.PacketContext;
import org.onosproject.net.packet.PacketService;
import org.onosproject.store.cluster.messaging.ClusterCommunicationServiceAdapter;
import org.onosproject.store.service.TestStorageService;
import org.opencord.aaa.AaaConfig;
import org.slf4j.Logger;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;

import static com.google.common.base.Preconditions.checkState;
import static junit.framework.TestCase.fail;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.notNullValue;
import static org.junit.Assert.assertNotEquals;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;
import static org.onosproject.net.NetTestTools.connectPoint;
import static org.onosproject.net.intent.TestTools.assertAfter;
import static org.slf4j.LoggerFactory.getLogger;

/**
 * Set of tests of the ONOS application component for AAA Statistics.
 */
public class AaaStatisticsTest extends AaaTestBase {

    static final String BAD_IP_ADDRESS = "198.51.100.0";
    static final Long ZERO = (long) 0;


    private final Logger log = getLogger(getClass());
    private AaaManager aaaManager;
    private AaaStatisticsManager aaaStatisticsManager;
    private AaaSupplicantMachineStatsManager aaaSupplicantStatsManager;

    class AaaManagerWithoutRadiusServer extends AaaManager {
        protected void sendRadiusPacket(RADIUS radiusPacket, InboundPacket inPkt) {
            super.sendRadiusPacket(radiusPacket, inPkt);
            aaaManager.aaaStatisticsManager.putOutgoingIdentifierToMap(radiusPacket.getIdentifier());
            savePacket(radiusPacket);
        }

        // changed the configuration of parent method to protected
        protected void configureRadiusCommunication() {
            PacketService pktService = new MockPacketService();
            ApplicationId appId = new CoreServiceAdapter().registerApplication("org.opencord.aaa");
            aaaManager.impl = new TestSocketBasedRadiusCommunicator(appId, pktService, aaaManager);
        }
    }

    /**
     * Mocks the AAAConfig class to force usage of an unroutable address for the
     * RADIUS server.
     */
    static class MockAaaConfig extends AaaConfig {
        @Override
        public InetAddress radiusIp() {
            try {
                return InetAddress.getByName(BAD_IP_ADDRESS);
            } catch (UnknownHostException ex) {
                throw new IllegalStateException(ex);
            }
        }
    }

    /**
     * Mocks the network config registry.
     */
    @SuppressWarnings("unchecked")
    private static final class TestNetworkConfigRegistry extends NetworkConfigRegistryAdapter {
        @Override
        public <S, C extends Config<S>> C getConfig(S subject, Class<C> configClass) {
            AaaConfig aaaConfig = new MockAaaConfig();
            return (C) aaaConfig;
        }
    }

    public static class TestEventDispatcher extends DefaultEventSinkRegistry implements EventDeliveryService {

        @Override
        @SuppressWarnings("unchecked")
        public synchronized void post(Event event) {
            EventSink sink = getSink(event.getClass());
            checkState(sink != null, "No sink for event %s", event);
            sink.process(event);
        }

        @Override
        public void setDispatchTimeLimit(long millis) {
        }

        @Override
        public long getDispatchTimeLimit() {
            return 0;
        }
    }

    /**
     * Set up the services required by the AAA application.
     */
    @Before
    public void setUp() {
        aaaManager = new AaaManagerWithoutRadiusServer();
        aaaManager.radiusOperationalStatusService = new RadiusOperationalStatusManager();
        aaaManager.netCfgService = new TestNetworkConfigRegistry();
        aaaManager.coreService = new CoreServiceAdapter();
        aaaManager.packetService = new MockPacketService();
        aaaManager.deviceService = new TestDeviceService();
        aaaManager.sadisService = new MockSadisService();
        aaaManager.cfgService = new MockCfgService();
        aaaManager.storageService = new TestStorageService();
        aaaStatisticsManager = new AaaStatisticsManager();
        aaaStatisticsManager.storageService = new TestStorageService();
        aaaStatisticsManager.clusterService = new ClusterServiceAdapter();
        aaaStatisticsManager.leadershipService = new AaaManagerTest.TestLeadershipService();
        aaaStatisticsManager.clusterCommunicationService = new ClusterCommunicationServiceAdapter();
        aaaSupplicantStatsManager = new AaaSupplicantMachineStatsManager();
        TestUtils.setField(aaaStatisticsManager, "eventDispatcher", new TestEventDispatcher());
        aaaStatisticsManager.activate(new MockComponentContext());
        TestUtils.setField(aaaSupplicantStatsManager, "eventDispatcher", new TestEventDispatcher());
        aaaSupplicantStatsManager.activate();
        aaaManager.aaaStatisticsManager = this.aaaStatisticsManager;
        aaaManager.aaaSupplicantStatsManager = this.aaaSupplicantStatsManager;
        TestUtils.setField(aaaManager, "eventDispatcher", new TestEventDispatcher());

        aaaManager.activate(new AaaTestBase.MockComponentContext());
    }

    /**
     * Tear down the AAA application.
     */
    @After
    public void tearDown() {
        aaaManager.deactivate(new AaaTestBase.MockComponentContext());
    }

    /**
     * Extracts the RADIUS packet from a packet sent by the supplicant.
     *
     * @param radius RADIUS packet sent by the supplicant
     * @throws DeserializationException if deserialization of the packet contents fails.
     */
    private void checkRadiusPacketFromSupplicant(RADIUS radius) throws DeserializationException {
        assertThat(radius, notNullValue());
        EAP eap = radius.decapsulateMessage();
        assertThat(eap, notNullValue());
    }

    /**
     * Fetches the sent packet at the given index. The requested packet must be the
     * last packet on the list.
     *
     * @param index index into sent packets array
     * @return packet
     */
    private BasePacket fetchPacket(int index) {
        BasePacket packet = savedPackets.get(index);
        assertThat(packet, notNullValue());
        return packet;
    }

    /**
     * Tests the authentication path through the AAA application.
     * And counts the aaa Stats for successful transmission.
     *
     * @throws DeserializationException if packed deserialization fails.
     */
    @Test
    public void testAaaStatisticsForAcceptedPackets() throws Exception {

        // (1) Supplicant start up
        Ethernet startPacket = constructSupplicantStartPacket();
        sendPacket(startPacket);

        Ethernet responsePacket = (Ethernet) fetchPacket(0);
        checkRadiusPacket(aaaManager, responsePacket, EAP.ATTR_IDENTITY);

        // (2) Supplicant identify

        Ethernet identifyPacket = constructSupplicantIdentifyPacket(null, EAP.ATTR_IDENTITY, (byte) 1, null);
        sendPacket(identifyPacket);

        RADIUS radiusIdentifyPacket = (RADIUS) fetchPacket(1);
        checkRadiusPacketFromSupplicant(radiusIdentifyPacket);

        assertThat(radiusIdentifyPacket.getCode(), is(RADIUS.RADIUS_CODE_ACCESS_REQUEST));
        assertThat(new String(radiusIdentifyPacket.getAttribute(RADIUSAttribute.RADIUS_ATTR_USERNAME).getValue()),
                is("testuser"));
        IpAddress nasIp = IpAddress.valueOf(IpAddress.Version.INET,
                radiusIdentifyPacket.getAttribute(RADIUSAttribute.RADIUS_ATTR_NAS_IP).getValue());
        assertThat(nasIp.toString(), is(aaaManager.nasIpAddress.getHostAddress()));

        // State machine should have been created by now

        StateMachine stateMachine = aaaManager.getStateMachine(SESSION_ID);
        assertThat(stateMachine, notNullValue());
        assertThat(stateMachine.state(), is(StateMachine.STATE_PENDING));

        // (3) RADIUS MD5 challenge

        RADIUS radiusCodeAccessChallengePacket = constructRadiusCodeAccessChallengePacket(
                RADIUS.RADIUS_CODE_ACCESS_CHALLENGE, EAP.ATTR_MD5, radiusIdentifyPacket.getIdentifier(),
                aaaManager.radiusSecret.getBytes());
        aaaManager.handleRadiusPacket(radiusCodeAccessChallengePacket);

        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            Ethernet radiusChallengeMD5Packet = (Ethernet) fetchPacket(2);
            checkRadiusPacket(aaaManager, radiusChallengeMD5Packet, EAP.ATTR_MD5);
            // (4) Supplicant MD5 response

            Ethernet md5RadiusPacket = null;
            try {
                md5RadiusPacket = constructSupplicantIdentifyPacket(stateMachine, EAP.ATTR_MD5,
                                      stateMachine.challengeIdentifier(), radiusChallengeMD5Packet);
            } catch (Exception e) {
                log.error(e.getMessage());
                fail();
            }
            sendPacket(md5RadiusPacket);
        });


        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            RADIUS responseMd5RadiusPacket = (RADIUS) fetchPacket(3);

            try {
                checkRadiusPacketFromSupplicant(responseMd5RadiusPacket);
            } catch (DeserializationException e) {
                log.error(e.getMessage());
                fail();
            }
            //assertThat(responseMd5RadiusPacket.getIdentifier(), is((byte) 9));
            assertThat(responseMd5RadiusPacket.getCode(), is(RADIUS.RADIUS_CODE_ACCESS_REQUEST));

            // State machine should be in pending state

            assertThat(stateMachine, notNullValue());
            assertThat(stateMachine.state(), is(StateMachine.STATE_PENDING));

            // (5) RADIUS Success

            RADIUS successPacket =
                    constructRadiusCodeAccessChallengePacket(RADIUS.RADIUS_CODE_ACCESS_ACCEPT, EAP.SUCCESS,
                                                             responseMd5RadiusPacket.getIdentifier(),
                                                             aaaManager.radiusSecret.getBytes());
            aaaManager.handleRadiusPacket((successPacket));
        });
        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            Ethernet supplicantSuccessPacket = (Ethernet) fetchPacket(4);

            checkRadiusPacket(aaaManager, supplicantSuccessPacket, EAP.SUCCESS);

            // State machine should be in authorized state

            assertThat(stateMachine, notNullValue());
            assertThat(stateMachine.state(), is(StateMachine.STATE_AUTHORIZED));

            //Check for increase of Stats
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolResIdentityMsgTrans(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolAuthSuccessTrans(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolStartReqTrans(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolTransRespNotNak(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapPktTxauthChooseEap(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getValidEapolFramesRx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolFramesTx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getReqEapFramesTx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getRequestIdFramesTx(), ZERO);
            assertEquals(aaaStatisticsManager.getAaaStats().getInvalidBodyLength(), ZERO);
            assertEquals(aaaStatisticsManager.getAaaStats().getInvalidPktType(), ZERO);
            assertEquals(aaaStatisticsManager.getAaaStats().getPendingResSupp(), ZERO);
            // Counts the aaa Statistics count and displays in the log
            countAaaStatistics();
        });

    }

    /** Tests invalid packets reaching AAA.
     *  And counts the aaa Stats for successful transmission.
     *   @throws DeserializationException
     *  if packed deserialization fails.
     */
    @Test
    public void testStatisticsForInvalidPackets() throws Exception {

        //Test Authenticator State Machine Status. Should be Pending
        // (1) Supplicant start up
        Ethernet startPacket = constructSupplicantStartPacket();
        sendPacket(startPacket);
        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            Ethernet responsePacket = (Ethernet) fetchPacket(0);
            checkRadiusPacket(aaaManager, responsePacket, EAP.ATTR_IDENTITY);
        });

        // (2) Supplicant identify

        Ethernet identifyPacket = constructSupplicantIdentifyPacket(null, EAP.ATTR_IDENTITY, (byte) 1, null);
        sendPacket(identifyPacket);

        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            RADIUS radiusIdentifyPacket = (RADIUS) fetchPacket(1);
            try {
                checkRadiusPacketFromSupplicant(radiusIdentifyPacket);
            } catch (DeserializationException e) {
                log.error(e.getMessage());
                fail();
            }

            assertThat(radiusIdentifyPacket.getCode(), is(RADIUS.RADIUS_CODE_ACCESS_REQUEST));
            assertThat(new String(radiusIdentifyPacket.getAttribute(RADIUSAttribute.RADIUS_ATTR_USERNAME).getValue()),
                       is("testuser"));
            IpAddress nasIp = IpAddress.valueOf(IpAddress.Version.INET,
                                                radiusIdentifyPacket.getAttribute(RADIUSAttribute.RADIUS_ATTR_NAS_IP)
                                                        .getValue());
            assertThat(nasIp.toString(), is(aaaManager.nasIpAddress.getHostAddress()));

            // State machine should have been created by now

            StateMachine stateMachine = aaaManager.getStateMachine(SESSION_ID);
            assertThat(stateMachine, notNullValue());
            assertThat(stateMachine.state(), is(StateMachine.STATE_PENDING));

            // (3) RADIUS NAK challenge

            RADIUS radiusCodeAccessChallengePacket = constructRadiusCodeAccessChallengePacket(
                    RADIUS.RADIUS_CODE_ACCESS_CHALLENGE, EAP.ATTR_NAK, radiusIdentifyPacket.getIdentifier(),
                    aaaManager.radiusSecret.getBytes());
            aaaManager.handleRadiusPacket(radiusCodeAccessChallengePacket);
        });

        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            Ethernet radiusChallengeNakPacket = (Ethernet) fetchPacket(2);
            checkRadiusPacket(aaaManager, radiusChallengeNakPacket, EAP.ATTR_NAK);

            // (4) Supplicant NAK response
            StateMachine stateMachine = aaaManager.getStateMachine(SESSION_ID);
            assertThat(stateMachine, notNullValue());
            Ethernet nakRadiusPacket = null;
            try {
                nakRadiusPacket = constructSupplicantIdentifyPacket(stateMachine, EAP.ATTR_NAK,
                                                                    stateMachine.challengeIdentifier(),
                                                                    radiusChallengeNakPacket);
            } catch (Exception e) {
                log.error(e.getMessage());
                fail();
            }
            sendPacket(nakRadiusPacket);
        });

        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            //Statistic Should be increased.
            assertNotEquals(aaaStatisticsManager.getAaaStats().getPendingResSupp(), ZERO);

            //Test if packet with invalid eapol type recieved.
            // Supplicant ASF Packet
            Ethernet invalidPacket = constructSupplicantAsfPacket();
            sendPacket(invalidPacket);
        });
        //Statistic Should be increased.
        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            assertNotEquals(aaaStatisticsManager.getAaaStats().getInvalidPktType(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getAccessRequestsTx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getChallengeResponsesRx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getDroppedResponsesRx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getInvalidValidatorsRx(), ZERO);
            // Counts the aaa Statistics count and displays in the log
            countAaaStatistics();
        });
    }


    /** Tests the count for defected packets.
     *
     * @throws DeserializationException if packed deserialization fails.
     */
    @Test
    public void testAaaStatisticsForDefectivePackets() throws Exception {
        // (1) Supplicant start up
        Ethernet startPacket = constructSupplicantStartPacket();
        sendPacket(startPacket);

        // (2) Supplicant identify

        Ethernet identifyPacket = constructSupplicantIdentifyPacket(null, EAP.ATTR_IDENTITY, (byte) 1, null);
        sendPacket(identifyPacket);

        RADIUS radiusIdentifyPacket = (RADIUS) fetchPacket(1);

        checkRadiusPacketFromSupplicant(radiusIdentifyPacket);

        // State machine should have been created by now

        StateMachine stateMachine = aaaManager.getStateMachine(SESSION_ID);

        // (3) RADIUS MD5 challenge

        RADIUS radiusCodeAccessChallengePacket = constructRadiusCodeAccessChallengePacket(
                RADIUS.RADIUS_CODE_ACCESS_CHALLENGE, EAP.ATTR_MD5, radiusIdentifyPacket.getIdentifier(),
                aaaManager.radiusSecret.getBytes());
        aaaManager.handleRadiusPacket(radiusCodeAccessChallengePacket);

        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            Ethernet radiusChallengeMD5Packet = (Ethernet) fetchPacket(2);

            // (4) Supplicant MD5 response

            Ethernet md5RadiusPacket = null;
            try {
                md5RadiusPacket = constructSupplicantIdentifyPacket(stateMachine, EAP.ATTR_MD5,
                                                                    stateMachine.challengeIdentifier(),
                                                                    radiusChallengeMD5Packet);
            } catch (Exception e) {
                log.error(e.getMessage());
                fail();
            }
            sendPacket(md5RadiusPacket);
        });

        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            aaaManager.aaaStatisticsManager.calculatePacketRoundtripTime();

            RADIUS responseMd5RadiusPacket = (RADIUS) fetchPacket(3);

            // (5) RADIUS Rejected

            RADIUS rejectedPacket =
                    constructRadiusCodeAccessChallengePacket(RADIUS.RADIUS_CODE_ACCESS_REJECT, EAP.FAILURE,
                                                             responseMd5RadiusPacket.getIdentifier(),
                                                             aaaManager.radiusSecret.getBytes());
            aaaManager.handleRadiusPacket((rejectedPacket));
        });

        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            Ethernet supplicantRejectedPacket = (Ethernet) fetchPacket(4);

            checkRadiusPacket(aaaManager, supplicantRejectedPacket, EAP.FAILURE);

            // State machine should be in unauthorized state
            assertThat(stateMachine, notNullValue());
            assertThat(stateMachine.state(), is(StateMachine.STATE_UNAUTHORIZED));
            // Calculated the total round trip time
            aaaManager.aaaStatisticsManager.calculatePacketRoundtripTime();

            //Check for increase of Stats
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolResIdentityMsgTrans(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolAuthFailureTrans(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolStartReqTrans(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapPktTxauthChooseEap(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolTransRespNotNak(), ZERO);

            assertNotEquals(aaaStatisticsManager.getAaaStats().getAccessRequestsTx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getChallengeResponsesRx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getDroppedResponsesRx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getInvalidValidatorsRx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getRejectResponsesRx(), ZERO);

            // Counts the aaa Statistics count
            countAaaStatistics();
        });

    }

    /*
     * Tests the retransmitted packet and malformed packet count
     *
     * @throws DeserializationException
     *  if packed deserialization fails.
     */
    @Test
    public void testRequestRetransmittedCount() throws Exception {

        // (1) Supplicant start up
        Ethernet startPacket = constructSupplicantStartPacket();
        sendPacket(startPacket);

        // (2) Supplicant identify

        Ethernet identifyPacket = constructSupplicantIdentifyPacket(null, EAP.ATTR_IDENTITY, (byte) 1, null);
        sendPacket(identifyPacket);

        RADIUS radiusIdentifyPacket = (RADIUS) fetchPacket(1);
        checkRadiusPacketFromSupplicant(radiusIdentifyPacket);

        // again creating pending state for same packet
        constructSupplicantIdentifyPacket(null, EAP.ATTR_IDENTITY, (byte) 1, null);
        sendPacket(identifyPacket);
        aaaManager.impl.handlePacketFromServer(null);
        aaaManager.aaaStatisticsManager.calculatePacketRoundtripTime();

        // creating malformed packet
        final ByteBuffer byteBuffer = ByteBuffer.wrap(startPacket.serialize());
        InboundPacket inPacket = new DefaultInboundPacket(connectPoint("1", 1),
                startPacket, byteBuffer);

        PacketContext context = new TestPacketContext(127L, inPacket, null, false);
        aaaManager.impl.handlePacketFromServer(context);

        // Check for increase of Stats
        assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolResIdentityMsgTrans(), ZERO);
        assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolStartReqTrans(), ZERO);

        assertNotEquals(aaaStatisticsManager.getAaaStats().getAccessRequestsTx(), ZERO);
        assertNotEquals(aaaStatisticsManager.getAaaStats().getDroppedResponsesRx(), ZERO);
        assertNotEquals(aaaStatisticsManager.getAaaStats().getPendingRequests(), ZERO);
        assertNotEquals(aaaStatisticsManager.getAaaStats().getMalformedResponsesRx(), ZERO);
        assertNotEquals(aaaStatisticsManager.getAaaStats().getRequestReTx(), ZERO);
        assertNotEquals(aaaStatisticsManager.getAaaStats().getUnknownTypeRx(), ZERO);
        assertNotEquals(aaaStatisticsManager.getAaaStats().getUnknownServerRx(), ZERO);

        countAaaStatistics();
    }

    /**
     * Tests the authentication path through the AAA application.
     * And counts the aaa Stats for logoff transactionXZ.
     *
     * @throws DeserializationException if packed deserialization fails.
     */
    @Test
    public void testAaaStatisticsForLogoffPackets() throws Exception {

        // (1) Supplicant start up
        Ethernet startPacket = constructSupplicantStartPacket();
        sendPacket(startPacket);

        Ethernet responsePacket = (Ethernet) fetchPacket(0);
        checkRadiusPacket(aaaManager, responsePacket, EAP.ATTR_IDENTITY);

        // (2) Supplicant identify

        Ethernet identifyPacket = constructSupplicantIdentifyPacket(null, EAP.ATTR_IDENTITY, (byte) 1, null);
        sendPacket(identifyPacket);

        RADIUS radiusIdentifyPacket = (RADIUS) fetchPacket(1);
        checkRadiusPacketFromSupplicant(radiusIdentifyPacket);

        assertThat(radiusIdentifyPacket.getCode(), is(RADIUS.RADIUS_CODE_ACCESS_REQUEST));
        assertThat(new String(radiusIdentifyPacket.getAttribute(RADIUSAttribute.RADIUS_ATTR_USERNAME).getValue()),
                is("testuser"));
        IpAddress nasIp = IpAddress.valueOf(IpAddress.Version.INET,
                radiusIdentifyPacket.getAttribute(RADIUSAttribute.RADIUS_ATTR_NAS_IP).getValue());
        assertThat(nasIp.toString(), is(aaaManager.nasIpAddress.getHostAddress()));

        // State machine should have been created by now

        //StateMachine stateMachine = StateMachine.lookupStateMachineBySessionId(SESSION_ID);
        StateMachine stateMachine = aaaManager.getStateMachine(SESSION_ID);
        assertThat(stateMachine, notNullValue());
        assertThat(stateMachine.state(), is(StateMachine.STATE_PENDING));

        // (3) RADIUS MD5 challenge

        RADIUS radiusCodeAccessChallengePacket = constructRadiusCodeAccessChallengePacket(
                RADIUS.RADIUS_CODE_ACCESS_CHALLENGE, EAP.ATTR_MD5,
                radiusIdentifyPacket.getIdentifier(), aaaManager.radiusSecret.getBytes());
        aaaManager.handleRadiusPacket(radiusCodeAccessChallengePacket);
        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            Ethernet radiusChallengeMD5Packet = (Ethernet) fetchPacket(2);
            checkRadiusPacket(aaaManager, radiusChallengeMD5Packet, EAP.ATTR_MD5);

            // (4) Supplicant MD5 response

            Ethernet md5RadiusPacket = null;
            try {
                md5RadiusPacket = constructSupplicantIdentifyPacket(stateMachine, EAP.ATTR_MD5,
                                                                    stateMachine.challengeIdentifier(),
                                                                    radiusChallengeMD5Packet);
            } catch (Exception e) {
                log.error(e.getMessage());
                fail();
            }
            sendPacket(md5RadiusPacket);
        });

        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            RADIUS responseMd5RadiusPacket = (RADIUS) fetchPacket(3);

            try {
                checkRadiusPacketFromSupplicant(responseMd5RadiusPacket);
            } catch (DeserializationException e) {
                log.error(e.getMessage());
                fail();
            }
            assertThat(responseMd5RadiusPacket.getCode(), is(RADIUS.RADIUS_CODE_ACCESS_REQUEST));

            // State machine should be in pending state

            assertThat(stateMachine, notNullValue());
            assertThat(stateMachine.state(), is(StateMachine.STATE_PENDING));

            // (5) RADIUS Success

            RADIUS successPacket =
                    constructRadiusCodeAccessChallengePacket(RADIUS.RADIUS_CODE_ACCESS_ACCEPT, EAP.SUCCESS,
                                                             responseMd5RadiusPacket.getIdentifier(),
                                                             aaaManager.radiusSecret.getBytes());
            aaaManager.handleRadiusPacket((successPacket));
        });

        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            Ethernet supplicantSuccessPacket = (Ethernet) fetchPacket(4);

            checkRadiusPacket(aaaManager, supplicantSuccessPacket, EAP.SUCCESS);

            // State machine should be in authorized state

            assertThat(stateMachine, notNullValue());
            assertThat(stateMachine.state(), is(StateMachine.STATE_AUTHORIZED));

            // Supplicant trigger EAP Logoff
            Ethernet logoffPacket = constructSupplicantLogoffPacket();
            sendPacket(logoffPacket);
        });
        assertAfter(ASSERTION_DELAY, ASSERTION_LENGTH, () -> {
            // State machine should be in logoff state
            assertThat(stateMachine, notNullValue());
            assertThat(stateMachine.state(), is(StateMachine.STATE_IDLE));

            //Check for increase in stats
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolLogoffRx(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolResIdentityMsgTrans(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolAuthSuccessTrans(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolStartReqTrans(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolTransRespNotNak(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getEapPktTxauthChooseEap(), ZERO);
            assertNotEquals(aaaStatisticsManager.getAaaStats().getAuthStateIdle(), ZERO);
            // Counts the aaa Statistics count
            countAaaStatistics();
        });

    }


    /** Tests the authentication path through the AAA application.
     *  And counts the aaa Stats for timeout.
     *   @throws DeserializationException
     *  if packed deserialization fails.
     */
    @Test
    public void testAaaStatisticsForTimeoutPackets() throws Exception {

        // (1) Supplicant start up
        Ethernet startPacket = constructSupplicantStartPacket();
        sendPacket(startPacket);

        Ethernet responsePacket = (Ethernet) fetchPacket(0);
        checkRadiusPacket(aaaManager, responsePacket, EAP.ATTR_IDENTITY);

        // (2) Supplicant identify

        Ethernet identifyPacket = constructSupplicantIdentifyPacket(null, EAP.ATTR_IDENTITY, (byte) 1, null);
        sendPacket(identifyPacket);

        RADIUS radiusIdentifyPacket = (RADIUS) fetchPacket(1);
        checkRadiusPacketFromSupplicant(radiusIdentifyPacket);

        assertThat(radiusIdentifyPacket.getCode(), is(RADIUS.RADIUS_CODE_ACCESS_REQUEST));
        assertThat(new String(radiusIdentifyPacket.getAttribute(RADIUSAttribute.RADIUS_ATTR_USERNAME).getValue()),
                is("testuser"));
        IpAddress nasIp = IpAddress.valueOf(IpAddress.Version.INET,
                  radiusIdentifyPacket.getAttribute(RADIUSAttribute.RADIUS_ATTR_NAS_IP).getValue());
        assertThat(nasIp.toString(), is(aaaManager.nasIpAddress.getHostAddress()));

        // State machine should have been created by now

        StateMachine stateMachine = aaaManager.getStateMachine(SESSION_ID);
        assertThat(stateMachine, notNullValue());
        assertThat(stateMachine.state(), is(StateMachine.STATE_PENDING));
        Thread.sleep((aaaManager.cleanupTimerTimeOutInMins / 2) + 1);

        // State machine should be in timeout state
        assertThat(stateMachine, notNullValue());
        assertThat(stateMachine.state(), is(StateMachine.STATE_PENDING));

        //Check for increase in stats
        assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolResIdentityMsgTrans(), ZERO);
        assertNotEquals(aaaStatisticsManager.getAaaStats().getEapolStartReqTrans(), ZERO);
       countAaaStatistics();

    }

    // Calculates the AAA statistics count.
    public void countAaaStatistics() {
        assertThat(aaaStatisticsManager.getAaaStats().getAcceptResponsesRx(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getAccessRequestsTx(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getChallengeResponsesRx(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getDroppedResponsesRx(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getInvalidValidatorsRx(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getMalformedResponsesRx(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getPendingRequests(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getRejectResponsesRx(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getRequestReTx(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getRequestRttMilis(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getUnknownServerRx(), notNullValue());
        assertThat(aaaStatisticsManager.getAaaStats().getUnknownTypeRx(), notNullValue());

    }

    /*
    * Mock implementation of SocketBasedRadiusCommunicator class.
    *
    */
    class TestSocketBasedRadiusCommunicator extends SocketBasedRadiusCommunicator {

        TestSocketBasedRadiusCommunicator(ApplicationId appId, PacketService pktService, AaaManager aaaManager) {
            super(appId, pktService, aaaManager);
        }

        /**
        * Wait 10 millis to simulate a non 0 rtt.
        *
        * @throws InterruptedException
        */
        private void waitPacket() throws InterruptedException {
            synchronized (this) {
                this.wait(10);
            }
        }

        // Implementation of socketBasedRadiusCommunicator--> run() method
        public void handlePacketFromServer(PacketContext context) {
            RADIUS incomingPkt = (RADIUS) fetchPacket(savedPackets.size() - 1);
            try {
                // wait a couple of millis to avoid rtt being 0
                waitPacket();
                if (context == null) {
                    aaaStatisticsManager.handleRoundtripTime(incomingPkt.getIdentifier());
                    aaaManager.handleRadiusPacket(incomingPkt);
                } else if (null != context) {
                    aaaManager.checkForPacketFromUnknownServer("100.100.100.0");
                    aaaStatisticsManager.handleRoundtripTime(incomingPkt.getIdentifier());
                    aaaManager.handleRadiusPacket(incomingPkt);
                    incomingPkt =
                            RADIUS.deserializer().deserialize(incomingPkt.generateAuthCode(), 0, 1);
                }
            } catch (DeserializationException dex) {
                aaaManager.aaaStatisticsManager.getAaaStats().increaseMalformedResponsesRx();
                aaaStatisticsManager.getAaaStats().countDroppedResponsesRx();
                log.error("Cannot deserialize packet", dex);
            } catch (InterruptedException inte) {
                Thread.currentThread().interrupt();
            }
        }

    }

}