/*
 * Copyright 2014-2015 Open Networking Laboratory
 *
 * 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.onosproject.sdnip;

import com.google.common.collect.Sets;
import org.junit.Before;
import org.junit.Ignore;
import org.junit.Test;
import org.onlab.junit.TestUtils.TestUtilsException;
import org.onlab.packet.Ethernet;
import org.onlab.packet.IPv4;
import org.onlab.packet.IpAddress;
import org.onlab.packet.IpPrefix;
import org.onlab.packet.MacAddress;
import org.onlab.packet.TpPort;
import org.onlab.packet.VlanId;
import org.onosproject.TestApplicationId;
import org.onosproject.core.ApplicationId;
import org.onosproject.incubator.net.intf.Interface;
import org.onosproject.incubator.net.intf.InterfaceService;
import org.onosproject.net.ConnectPoint;
import org.onosproject.net.DeviceId;
import org.onosproject.net.PortNumber;
import org.onosproject.net.config.NetworkConfigListener;
import org.onosproject.net.config.NetworkConfigService;
import org.onosproject.net.flow.DefaultTrafficSelector;
import org.onosproject.net.flow.DefaultTrafficTreatment;
import org.onosproject.net.flow.TrafficSelector;
import org.onosproject.net.flow.TrafficTreatment;
import org.onosproject.net.host.InterfaceIpAddress;
import org.onosproject.net.intent.AbstractIntentTest;
import org.onosproject.net.intent.Intent;
import org.onosproject.net.intent.Key;
import org.onosproject.net.intent.PointToPointIntent;
import org.onosproject.routing.IntentSynchronizationService;
import org.onosproject.routing.config.BgpConfig;
import org.onosproject.routing.config.BgpPeer;
import org.onosproject.routing.config.BgpSpeaker;
import org.onosproject.routing.config.InterfaceAddress;
import org.onosproject.routing.config.RoutingConfigurationService;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;

import static org.easymock.EasyMock.anyObject;
import static org.easymock.EasyMock.createMock;
import static org.easymock.EasyMock.expect;
import static org.easymock.EasyMock.expectLastCall;
import static org.easymock.EasyMock.replay;
import static org.easymock.EasyMock.reset;
import static org.easymock.EasyMock.verify;
import static org.onosproject.routing.TestIntentServiceHelper.eqExceptId;

/**
 * Unit tests for PeerConnectivityManager.
 */
public class PeerConnectivityManagerTest extends AbstractIntentTest {

    private static final ApplicationId APPID = TestApplicationId.create("foo");

    private static final ApplicationId CONFIG_APP_ID = APPID;

    private PeerConnectivityManager peerConnectivityManager;
    private IntentSynchronizationService intentSynchronizer;
    private RoutingConfigurationService routingConfig;
    private InterfaceService interfaceService;
    private NetworkConfigService networkConfigService;

    private Set<BgpConfig.BgpSpeakerConfig> bgpSpeakers;
    private Map<String, Interface> interfaces;
    private Map<IpAddress, BgpPeer> peers;

    private BgpConfig bgpConfig;

    private List<PointToPointIntent> intentList;

    private final String dpid1 = "00:00:00:00:00:00:00:01";
    private final String dpid2 = "00:00:00:00:00:00:00:02";

    private final DeviceId deviceId1 =
            DeviceId.deviceId(SdnIp.dpidToUri(dpid1));
    private final DeviceId deviceId2 =
            DeviceId.deviceId(SdnIp.dpidToUri(dpid2));

    // Interfaces connected to BGP speakers
    private final ConnectPoint s1Eth100 =
            new ConnectPoint(deviceId1, PortNumber.portNumber(100));
    private final ConnectPoint s2Eth100 =
            new ConnectPoint(deviceId2, PortNumber.portNumber(100));

    // Interfaces connected to BGP peers
    private final ConnectPoint s1Eth1 =
            new ConnectPoint(deviceId1, PortNumber.portNumber(1));
    private final ConnectPoint s2Eth1 =
            new ConnectPoint(deviceId2, PortNumber.portNumber(1));

    private final TrafficTreatment noTreatment =
            DefaultTrafficTreatment.emptyTreatment();

    @Before
    public void setUp() throws Exception {
        super.setUp();
        routingConfig = createMock(RoutingConfigurationService.class);
        interfaceService = createMock(InterfaceService.class);
        networkConfigService = createMock(NetworkConfigService.class);
        networkConfigService.addListener(anyObject(NetworkConfigListener.class));
        expectLastCall().anyTimes();
        bgpConfig = createMock(BgpConfig.class);

        // These will set expectations on routingConfig and interfaceService
        bgpSpeakers = setUpBgpSpeakers();
        interfaces = Collections.unmodifiableMap(setUpInterfaces());
        peers = setUpPeers();

        initPeerConnectivity();
        intentList = setUpIntentList();
    }

    /**
     * Sets up BGP speakers.
     *
     * @return configured BGP speakers as a map from speaker name to speaker
     */
    private Set<BgpConfig.BgpSpeakerConfig> setUpBgpSpeakers() {

        BgpConfig.BgpSpeakerConfig speaker1 = new BgpConfig.BgpSpeakerConfig(
                Optional.empty(),
                s1Eth100, Collections.singleton(IpAddress.valueOf("192.168.10.1")));

        BgpConfig.BgpSpeakerConfig speaker2 = new BgpConfig.BgpSpeakerConfig(
                Optional.empty(),
                s1Eth100, Sets.newHashSet(IpAddress.valueOf("192.168.20.1"),
                IpAddress.valueOf("192.168.30.1")));

        Set<BgpConfig.BgpSpeakerConfig> bgpSpeakers = Sets.newHashSet();
        bgpSpeakers.add(speaker1);
        bgpSpeakers.add(speaker2);

        return bgpSpeakers;
    }

    /**
     * Sets up logical interfaces, which emulate the configured interfaces
     * in SDN-IP application.
     *
     * @return configured interfaces as a map from interface name to Interface
     */
    private Map<String, Interface> setUpInterfaces() {

        Map<String, Interface> configuredInterfaces = new HashMap<>();

        String interfaceSw1Eth1 = "s1-eth1";
        InterfaceIpAddress ia1 =
            new InterfaceIpAddress(IpAddress.valueOf("192.168.10.101"),
                                   IpPrefix.valueOf("192.168.10.0/24"));
        Interface intfsw1eth1 = new Interface(s1Eth1,
                Collections.singleton(ia1),
                MacAddress.valueOf("00:00:00:00:00:01"),
                VlanId.NONE);

        configuredInterfaces.put(interfaceSw1Eth1, intfsw1eth1);
        String interfaceSw2Eth1 = "s2-eth1";
        InterfaceIpAddress ia2 =
            new InterfaceIpAddress(IpAddress.valueOf("192.168.20.101"),
                                   IpPrefix.valueOf("192.168.20.0/24"));
        Interface intfsw2eth1 = new Interface(s2Eth1,
                Collections.singleton(ia2),
                MacAddress.valueOf("00:00:00:00:00:02"),
                VlanId.NONE);
        configuredInterfaces.put(interfaceSw2Eth1, intfsw2eth1);

        String interfaceSw2Eth1intf2 = "s2-eth1_2";
        InterfaceIpAddress ia3 =
                new InterfaceIpAddress(IpAddress.valueOf("192.168.30.101"),
                        IpPrefix.valueOf("192.168.30.0/24"));
        Interface intfsw2eth1intf2 = new Interface(s2Eth1,
                Collections.singleton(ia3),
                MacAddress.valueOf("00:00:00:00:00:03"),
                VlanId.NONE);
        configuredInterfaces.put(interfaceSw2Eth1intf2, intfsw2eth1intf2);

        expect(interfaceService.getInterfacesByPort(s1Eth1))
                .andReturn(Collections.singleton(intfsw1eth1)).anyTimes();
        expect(interfaceService.getInterfacesByIp(IpAddress.valueOf("192.168.10.101")))
                .andReturn(Collections.singleton(intfsw1eth1)).anyTimes();
        expect(interfaceService.getMatchingInterface(IpAddress.valueOf("192.168.10.1")))
                .andReturn(intfsw1eth1).anyTimes();
        expect(interfaceService.getInterfacesByPort(s2Eth1))
                .andReturn(Collections.singleton(intfsw2eth1)).anyTimes();
        expect(interfaceService.getInterfacesByIp(IpAddress.valueOf("192.168.20.101")))
                .andReturn(Collections.singleton(intfsw2eth1)).anyTimes();
        expect(interfaceService.getMatchingInterface(IpAddress.valueOf("192.168.20.1")))
                .andReturn(intfsw2eth1).anyTimes();

        expect(interfaceService.getInterfacesByIp(IpAddress.valueOf("192.168.30.101")))
                .andReturn(Collections.singleton(intfsw2eth1intf2)).anyTimes();
        expect(interfaceService.getMatchingInterface(IpAddress.valueOf("192.168.30.1")))
                .andReturn(intfsw2eth1intf2).anyTimes();

        // Non-existent interface used during one of the tests
        expect(interfaceService.getInterfacesByPort(new ConnectPoint(
                DeviceId.deviceId(SdnIp.dpidToUri("00:00:00:00:00:00:01:00")),
                PortNumber.portNumber(1))))
                    .andReturn(null).anyTimes();

        expect(interfaceService.getInterfaces()).andReturn(
                Sets.newHashSet(configuredInterfaces.values())).anyTimes();

        return configuredInterfaces;
    }

    /**
     * Sets up BGP daemon peers.
     *
     * @return configured BGP peers as a MAP from peer IP address to BgpPeer
     */
    private Map<IpAddress, BgpPeer> setUpPeers() {

        Map<IpAddress, BgpPeer> configuredPeers = new HashMap<>();

        String peerSw1Eth1 = "192.168.10.1";
        configuredPeers.put(IpAddress.valueOf(peerSw1Eth1),
                new BgpPeer(dpid1, 1, peerSw1Eth1));

        // Two BGP peers are connected to switch 2 port 1.
        String peer1Sw2Eth1 = "192.168.20.1";
        configuredPeers.put(IpAddress.valueOf(peer1Sw2Eth1),
                new BgpPeer(dpid2, 1, peer1Sw2Eth1));

        String peer2Sw2Eth1 = "192.168.30.1";
        configuredPeers.put(IpAddress.valueOf(peer2Sw2Eth1),
                new BgpPeer(dpid2, 1, peer2Sw2Eth1));

        return configuredPeers;
    }

    /**
     * Sets up expected point to point intent list.
     *
     * @return point to point intent list
     */
    private List<PointToPointIntent> setUpIntentList() {
        intentList = new ArrayList<>();

        setUpBgpIntents();
        setUpIcmpIntents();

        return intentList;
    }

    /**
     * Constructs a BGP intent and put it into the intentList.
     * <p/>
     * The purpose of this method is too simplify the setUpBgpIntents() method,
     * and to make the setUpBgpIntents() easy to read.
     *
     * @param srcPrefix source IP prefix to match
     * @param dstPrefix destination IP prefix to match
     * @param srcTcpPort source TCP port to match
     * @param dstTcpPort destination TCP port to match
     * @param srcConnectPoint source connect point for PointToPointIntent
     * @param dstConnectPoint destination connect point for PointToPointIntent
     */
    private void bgpPathintentConstructor(String srcPrefix, String dstPrefix,
            Short srcTcpPort, Short dstTcpPort,
            ConnectPoint srcConnectPoint, ConnectPoint dstConnectPoint) {

        TrafficSelector.Builder builder = DefaultTrafficSelector.builder()
                .matchEthType(Ethernet.TYPE_IPV4)
                .matchIPProtocol(IPv4.PROTOCOL_TCP)
                .matchIPSrc(IpPrefix.valueOf(srcPrefix))
                .matchIPDst(IpPrefix.valueOf(dstPrefix));

        if (srcTcpPort != null) {
            builder.matchTcpSrc(TpPort.tpPort(srcTcpPort));
        }
        if (dstTcpPort != null) {
            builder.matchTcpDst(TpPort.tpPort(dstTcpPort));
        }

        Key key = Key.of(srcPrefix.split("/")[0] + "-" + dstPrefix.split("/")[0]
                + "-" + ((srcTcpPort == null) ? "dst" : "src"), APPID);

        PointToPointIntent intent = PointToPointIntent.builder()
                .appId(APPID)
                .key(key)
                .selector(builder.build())
                .treatment(noTreatment)
                .ingressPoint(srcConnectPoint)
                .egressPoint(dstConnectPoint)
                .build();

        intentList.add(intent);
    }

    /**
     * Sets up intents for BGP paths.
     */
    private void setUpBgpIntents() {

        Short bgpPort = 179;

        // Start to build intents between BGP speaker1 and BGP peer1
        bgpPathintentConstructor(
                "192.168.10.101/32", "192.168.10.1/32", null, bgpPort,
                s1Eth100, s1Eth1);
        bgpPathintentConstructor(
                "192.168.10.101/32", "192.168.10.1/32", bgpPort, null,
                s1Eth100, s1Eth1);

        bgpPathintentConstructor(
                "192.168.10.1/32", "192.168.10.101/32", null, bgpPort,
                s1Eth1, s1Eth100);
        bgpPathintentConstructor(
                "192.168.10.1/32", "192.168.10.101/32", bgpPort, null,
                s1Eth1, s1Eth100);

        // Start to build intents between BGP speaker1 and BGP peer2
        bgpPathintentConstructor(
                "192.168.20.101/32", "192.168.20.1/32", null, bgpPort,
                s1Eth100, s2Eth1);
        bgpPathintentConstructor(
                "192.168.20.101/32", "192.168.20.1/32", bgpPort, null,
                s1Eth100, s2Eth1);

        bgpPathintentConstructor(
                "192.168.20.1/32", "192.168.20.101/32", null, bgpPort,
                s2Eth1, s1Eth100);
        bgpPathintentConstructor(
                "192.168.20.1/32", "192.168.20.101/32", bgpPort, null,
                s2Eth1, s1Eth100);

        //
        // Start to build intents between BGP speaker3 and BGP peer1
        bgpPathintentConstructor(
                "192.168.30.101/32", "192.168.30.1/32", null, bgpPort,
                s1Eth100, s2Eth1);
        bgpPathintentConstructor(
                "192.168.30.101/32", "192.168.30.1/32", bgpPort, null,
                s1Eth100, s2Eth1);

        bgpPathintentConstructor(
                "192.168.30.1/32", "192.168.30.101/32", null, bgpPort,
                s2Eth1, s1Eth100);
        bgpPathintentConstructor(
                "192.168.30.1/32", "192.168.30.101/32", bgpPort, null,
                s2Eth1, s1Eth100);
    }

    /**
     * Constructs a BGP intent and put it into the intentList.
     * <p/>
     * The purpose of this method is too simplify the setUpBgpIntents() method,
     * and to make the setUpBgpIntents() easy to read.
     *
     * @param srcPrefix source IP prefix to match
     * @param dstPrefix destination IP prefix to match
     * @param srcConnectPoint source connect point for PointToPointIntent
     * @param dstConnectPoint destination connect point for PointToPointIntent
     */
    private void icmpPathintentConstructor(String srcPrefix, String dstPrefix,
            ConnectPoint srcConnectPoint, ConnectPoint dstConnectPoint) {

        TrafficSelector selector = DefaultTrafficSelector.builder()
                .matchEthType(Ethernet.TYPE_IPV4)
                .matchIPProtocol(IPv4.PROTOCOL_ICMP)
                .matchIPSrc(IpPrefix.valueOf(srcPrefix))
                .matchIPDst(IpPrefix.valueOf(dstPrefix))
                .build();

        Key key = Key.of(srcPrefix.split("/")[0] + "-" + dstPrefix.split("/")[0]
                + "-" + "icmp", APPID);

        PointToPointIntent intent = PointToPointIntent.builder()
                .appId(APPID)
                .key(key)
                .selector(selector)
                .treatment(noTreatment)
                .ingressPoint(srcConnectPoint)
                .egressPoint(dstConnectPoint)
                .build();

        intentList.add(intent);
    }

    /**
     * Sets up intents for ICMP paths.
     */
    private void setUpIcmpIntents() {
        // Start to build intents between BGP speaker1 and BGP peer1
        icmpPathintentConstructor(
                "192.168.10.101/32", "192.168.10.1/32", s1Eth100, s1Eth1);
        icmpPathintentConstructor(
                "192.168.10.1/32", "192.168.10.101/32", s1Eth1, s1Eth100);

        // Start to build intents between BGP speaker1 and BGP peer2
        icmpPathintentConstructor(
                "192.168.20.101/32", "192.168.20.1/32", s1Eth100, s2Eth1);
        icmpPathintentConstructor(
                "192.168.20.1/32", "192.168.20.101/32", s2Eth1, s1Eth100);

        icmpPathintentConstructor(
                "192.168.30.101/32", "192.168.30.1/32", s1Eth100, s2Eth1);
        icmpPathintentConstructor(
                "192.168.30.1/32", "192.168.30.101/32", s2Eth1, s1Eth100);
    }

    /**
     * Initializes peer connectivity testing environment.
     *
     * @throws TestUtilsException if exceptions when using TestUtils
     */
    private void initPeerConnectivity() throws TestUtilsException {
        expect(routingConfig.getBgpPeers()).andReturn(peers).anyTimes();
        expect(bgpConfig.bgpSpeakers()).andReturn(bgpSpeakers).anyTimes();
        replay(bgpConfig);
        expect(networkConfigService.getConfig(APPID, BgpConfig.class))
                .andReturn(bgpConfig).anyTimes();
        replay(networkConfigService);
        replay(routingConfig);
        replay(interfaceService);

        intentSynchronizer = createMock(IntentSynchronizationService.class);
        replay(intentSynchronizer);

        peerConnectivityManager =
            new PeerConnectivityManager(APPID, intentSynchronizer,
                                        networkConfigService,
                                        CONFIG_APP_ID,
                                        interfaceService);
    }

    /**
     * Tests whether peer connectivity manager can set up correct BGP and
     * ICMP intents according to specific configuration.
     * <p/>
     * Two tricky cases included in the configuration are: 2 peers on a same
     * switch port, peer on the same switch with BGPd.
     */
    @Test
    public void testConnectionSetup() {
        reset(intentSynchronizer);

        // Setup the expected intents
        for (Intent intent : intentList) {
            intentSynchronizer.submit(eqExceptId(intent));
        }
        replay(intentSynchronizer);

        // Running the interface to be tested.
        peerConnectivityManager.start();

        verify(intentSynchronizer);
    }

    /**
     *  Tests a corner case, when there are no interfaces in the configuration.
     */
    @Test
    public void testNullInterfaces() {
        reset(interfaceService);

        expect(interfaceService.getInterfaces()).andReturn(
                Sets.newHashSet()).anyTimes();
        expect(interfaceService.getInterfacesByPort(s2Eth1))
                .andReturn(Collections.emptySet()).anyTimes();
        expect(interfaceService.getInterfacesByPort(s1Eth1))
        .andReturn(Collections.emptySet()).anyTimes();
        expect(interfaceService.getInterfacesByIp(IpAddress.valueOf("192.168.10.101")))
                .andReturn(Collections.emptySet()).anyTimes();
        expect(interfaceService.getMatchingInterface(IpAddress.valueOf("192.168.10.1")))
                .andReturn(null).anyTimes();
        expect(interfaceService.getInterfacesByIp(IpAddress.valueOf("192.168.20.101")))
                .andReturn(Collections.emptySet()).anyTimes();
        expect(interfaceService.getMatchingInterface(IpAddress.valueOf("192.168.20.1")))
                .andReturn(null).anyTimes();
        expect(interfaceService.getInterfacesByIp(IpAddress.valueOf("192.168.30.101")))
                .andReturn(Collections.emptySet()).anyTimes();
        expect(interfaceService.getMatchingInterface(IpAddress.valueOf("192.168.30.1")))
                .andReturn(null).anyTimes();

        replay(interfaceService);

        reset(intentSynchronizer);
        replay(intentSynchronizer);
        peerConnectivityManager.start();
        verify(intentSynchronizer);
    }

    /**
     *  Tests a corner case, when there is no BGP speakers in the configuration.
     */
    @Test
    public void testNullBgpSpeakers() {
        reset(routingConfig);
        reset(bgpConfig);

        expect(bgpConfig.bgpSpeakers()).andReturn(Collections.emptySet()).anyTimes();
        replay(bgpConfig);
        expect(routingConfig.getBgpPeers()).andReturn(peers).anyTimes();
        replay(routingConfig);

        reset(intentSynchronizer);
        replay(intentSynchronizer);
        peerConnectivityManager.start();
        verify(intentSynchronizer);
    }

    /**
     * Tests a corner case, when there is no Interface configured for one BGP
     * peer.
     */
    @Test
    public void testNoPeerInterface() {
        String peerSw100Eth1 = "192.168.200.1";
        peers.put(IpAddress.valueOf(peerSw100Eth1),
                new BgpPeer("00:00:00:00:00:00:01:00", 1, peerSw100Eth1));
        testConnectionSetup();
    }

    /**
     * Tests a corner case, when there is no Interface configured for one BGP
     * speaker.
     */
    @Ignore
    @Test
    public void testNoSpeakerInterface() {
        BgpSpeaker bgpSpeaker100 = new BgpSpeaker(
                "bgpSpeaker100",
                "00:00:00:00:00:00:01:00", 100,
                "00:00:00:00:01:00");
        List<InterfaceAddress> interfaceAddresses100 = new LinkedList<>();
        interfaceAddresses100.add(new InterfaceAddress(dpid1, 1, "192.168.10.201"));
        interfaceAddresses100.add(new InterfaceAddress(dpid2, 1, "192.168.20.201"));
        bgpSpeaker100.setInterfaceAddresses(interfaceAddresses100);
        testConnectionSetup();
    }
}