/*
 * Copyright 2016-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.olt.impl;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Strings.isNullOrEmpty;
import static java.util.concurrent.Executors.newSingleThreadScheduledExecutor;
import static org.onlab.util.Tools.get;
import static org.onlab.util.Tools.groupedThreads;
import static org.slf4j.LoggerFactory.getLogger;

import java.util.AbstractMap;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Dictionary;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.Properties;
import java.util.Set;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.stream.Collectors;

import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.felix.scr.annotations.Modified;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.ReferenceCardinality;
import org.apache.felix.scr.annotations.Service;
import org.onlab.packet.EthType;
import org.onlab.packet.IPv4;
import org.onlab.packet.IPv6;
import org.onlab.packet.TpPort;
import org.onlab.packet.VlanId;
import org.onlab.util.Tools;
import org.onosproject.cfg.ComponentConfigService;
import org.onosproject.core.ApplicationId;
import org.onosproject.core.CoreService;
import org.onosproject.event.AbstractListenerManager;
import org.onosproject.mastership.MastershipService;
import org.onosproject.net.AnnotationKeys;
import org.onosproject.net.ConnectPoint;
import org.onosproject.net.Device;
import org.onosproject.net.DeviceId;
import org.onosproject.net.Port;
import org.onosproject.net.PortNumber;
import org.onosproject.net.device.DeviceEvent;
import org.onosproject.net.device.DeviceListener;
import org.onosproject.net.device.DeviceService;
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.flow.criteria.Criteria;
import org.onosproject.net.flowobjective.DefaultFilteringObjective;
import org.onosproject.net.flowobjective.DefaultForwardingObjective;
import org.onosproject.net.flowobjective.FilteringObjective;
import org.onosproject.net.flowobjective.FlowObjectiveService;
import org.onosproject.net.flowobjective.ForwardingObjective;
import org.onosproject.net.flowobjective.Objective;
import org.onosproject.net.flowobjective.ObjectiveContext;
import org.onosproject.net.flowobjective.ObjectiveError;
import org.onosproject.net.meter.Band;
import org.onosproject.net.meter.DefaultBand;
import org.onosproject.net.meter.DefaultMeterRequest;
import org.onosproject.net.meter.Meter;
import org.onosproject.net.meter.MeterContext;
import org.onosproject.net.meter.MeterEvent;
import org.onosproject.net.meter.MeterFailReason;
import org.onosproject.net.meter.MeterId;
import org.onosproject.net.meter.MeterKey;
import org.onosproject.net.meter.MeterListener;
import org.onosproject.net.meter.MeterRequest;
import org.onosproject.net.meter.MeterService;
import org.onosproject.store.serializers.KryoNamespaces;
import org.onosproject.store.service.ConsistentMultimap;
import org.onosproject.store.service.Serializer;
import org.onosproject.store.service.StorageService;
import org.opencord.olt.AccessDeviceEvent;
import org.opencord.olt.AccessDeviceListener;
import org.opencord.olt.AccessDeviceService;
import org.opencord.olt.AccessSubscriberId;
import org.opencord.sadis.BandwidthProfileInformation;
import org.opencord.sadis.BaseInformationService;
import org.opencord.sadis.SadisService;
import org.opencord.sadis.SubscriberAndDeviceInformation;
import org.osgi.service.component.ComponentContext;
import org.slf4j.Logger;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;

/**
 * Provisions rules on access devices.
 */
@Service
@Component(immediate = true)
public class Olt
        extends AbstractListenerManager<AccessDeviceEvent, AccessDeviceListener>
        implements AccessDeviceService {
    private static final String APP_NAME = "org.opencord.olt";

    private static final short DEFAULT_VLAN = 0;
    private static final short EAPOL_DEFAULT_VLAN = 4091;
    private static final int DEFAULT_TP_ID = 64;
    private static final String DEFAULT_BP_ID = "Default";
    private static final String ADDITIONAL_VLANS = "additional-vlans";
    private static final String NO_UPLINK_PORT = "No uplink port found for OLT device {}";
    private static final String INSTALLED = "installed";
    private static final String REMOVED = "removed";
    private static final String INSTALLATION = "installation";
    private static final String REMOVAL = "removal";

    private final Logger log = getLogger(getClass());

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected FlowObjectiveService flowObjectiveService;

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected MastershipService mastershipService;

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected DeviceService deviceService;

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected CoreService coreService;

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected ComponentConfigService componentConfigService;

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected SadisService sadisService;

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected MeterService meterService;

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected StorageService storageService;

    @Property(name = "defaultVlan", intValue = DEFAULT_VLAN,
            label = "Default VLAN RG<->ONU traffic")
    private int defaultVlan = DEFAULT_VLAN;

    @Property(name = "enableDhcpOnProvisioning", boolValue = true,
            label = "Create the DHCP Flow rules when a subscriber is provisioned")
    protected boolean enableDhcpOnProvisioning = false;

    @Property(name = "enableDhcpV4", boolValue = true,
            label = "Enable flows for DHCP v4")
    protected boolean enableDhcpV4 = true;

    @Property(name = "enableDhcpV6", boolValue = true,
            label = "Enable flows for DHCP v6")
    protected boolean enableDhcpV6 = false;

    @Property(name = "enableIgmpOnProvisioning", boolValue = false,
            label = "Create IGMP Flow rules when a subscriber is provisioned")
    protected boolean enableIgmpOnProvisioning = false;

    @Property(name = "deleteMeters", boolValue = true,
            label = "Deleting Meters based on flow count statistics")
    protected boolean deleteMeters = true;

    @Property(name = "defaultTechProfileId", intValue = DEFAULT_TP_ID,
            label = "Default technology profile id that is used for authentication trap flows")
    protected int defaultTechProfileId = DEFAULT_TP_ID;

    @Property(name = "defaultBpId", value = DEFAULT_BP_ID,
            label = "Default bandwidth profile id that is used for authentication trap flows")
    protected String defaultBpId = DEFAULT_BP_ID;

    @Property(name = "enableEapol", boolValue = true,
            label = "Send EAPOL authentication trap flows before subscriber provisioning")
    protected boolean enableEapol = true;

    private final DeviceListener deviceListener = new InternalDeviceListener();
    private final MeterListener meterListener = new InternalMeterListener();

    private ApplicationId appId;
    protected BaseInformationService<SubscriberAndDeviceInformation> subsService;
    private BaseInformationService<BandwidthProfileInformation> bpService;

    private Map<String, List<MeterKey>> bpInfoToMeter = new ConcurrentHashMap<>();

    private ExecutorService oltInstallers = Executors.newFixedThreadPool(4,
            groupedThreads("onos/olt-service",
                    "olt-installer-%d"));

    private ConsistentMultimap<ConnectPoint, Map.Entry<VlanId, VlanId>> additionalVlans;

    protected ExecutorService eventExecutor;

    private Map<ConnectPoint, SubscriberAndDeviceInformation> programmedSubs;
    private Set<MeterKey> programmedMeters;


    @Activate
    public void activate(ComponentContext context) {
        eventExecutor = newSingleThreadScheduledExecutor(groupedThreads("onos/olt", "events-%d", log));
        modified(context);
        appId = coreService.registerApplication(APP_NAME);

        // ensure that flow rules are purged from flow-store upon olt-disconnection
        // when olt reconnects, the port-numbers may change for the ONUs
        // making flows pushed earlier invalid
        componentConfigService
                .preSetProperty("org.onosproject.net.flow.impl.FlowRuleManager",
                        "purgeOnDisconnection", "true");
        componentConfigService
                .preSetProperty("org.onosproject.net.meter.impl.MeterManager",
                        "purgeOnDisconnection", "true");
        componentConfigService.registerProperties(getClass());
        programmedSubs = Maps.newConcurrentMap();
        programmedMeters = ConcurrentHashMap.newKeySet();

        eventDispatcher.addSink(AccessDeviceEvent.class, listenerRegistry);

        subsService = sadisService.getSubscriberInfoService();
        bpService = sadisService.getBandwidthProfileService();

        // look for all provisioned devices in Sadis and create EAPOL flows for the
        // UNI ports
        Iterable<Device> devices = deviceService.getDevices();
        for (Device d : devices) {
            checkAndCreateDeviceFlows(d);
        }

        additionalVlans = storageService.<ConnectPoint, Map.Entry<VlanId, VlanId>>consistentMultimapBuilder()
                .withName(ADDITIONAL_VLANS)
                .withSerializer(Serializer.using(Arrays.asList(KryoNamespaces.API),
                        AbstractMap.SimpleEntry.class))
                .build();

        deviceService.addListener(deviceListener);
        meterService.addListener(meterListener);

        log.info("Started with Application ID {}", appId.id());
    }

    @Deactivate
    public void deactivate() {
        componentConfigService.unregisterProperties(getClass(), false);
        deviceService.removeListener(deviceListener);
        meterService.removeListener(meterListener);
        eventDispatcher.removeSink(AccessDeviceEvent.class);
        log.info("Stopped");
    }

    @Modified
    public void modified(ComponentContext context) {
        Dictionary<?, ?> properties = context != null ? context.getProperties() : new Properties();

        try {
            String s = get(properties, "defaultVlan");
            defaultVlan = isNullOrEmpty(s) ? DEFAULT_VLAN : Integer.parseInt(s.trim());

            Boolean o = Tools.isPropertyEnabled(properties, "enableDhcpOnProvisioning");
            if (o != null) {
                enableDhcpOnProvisioning = o;
            }

            Boolean v4 = Tools.isPropertyEnabled(properties, "enableDhcpV4");
            if (v4 != null) {
                enableDhcpV4 = v4;
            }

            Boolean v6 = Tools.isPropertyEnabled(properties, "enableDhcpV6");
            if (v6 != null) {
                enableDhcpV6 = v6;
            }

            Boolean p = Tools.isPropertyEnabled(properties, "enableIgmpOnProvisioning");
            if (p != null) {
                enableIgmpOnProvisioning = p;
            }

            log.info("DHCP Settings [enableDhcpOnProvisioning: {}, enableDhcpV4: {}, enableDhcpV6: {}]",
                    enableDhcpOnProvisioning, enableDhcpV4, enableDhcpV6);

            Boolean d = Tools.isPropertyEnabled(properties, "deleteMeters");
            if (d != null) {
                deleteMeters = d;
            }

            String tpId = get(properties, "defaultTechProfileId");
            defaultTechProfileId = isNullOrEmpty(s) ? DEFAULT_TP_ID : Integer.parseInt(tpId.trim());

            String bpId = get(properties, "defaultBpId");
            defaultBpId = bpId;

            Boolean eap = Tools.isPropertyEnabled(properties, "enableEapol");
            if (eap != null) {
                enableEapol = eap;
            }

        } catch (Exception e) {
            defaultVlan = DEFAULT_VLAN;
        }
    }

    @Override
    public boolean provisionSubscriber(ConnectPoint connectPoint) {
        log.info("Call to provision subscriber at {}", connectPoint);
        DeviceId deviceId = connectPoint.deviceId();
        PortNumber subscriberPortNo = connectPoint.port();

        checkNotNull(deviceService.getPort(deviceId, subscriberPortNo),
                "Invalid connect point");
        // Find the subscriber on this connect point
        SubscriberAndDeviceInformation sub = getSubscriber(connectPoint);
        if (sub == null) {
            log.warn("No subscriber found for {}", connectPoint);
            return false;
        }

        // Get the uplink port
        Port uplinkPort = getUplinkPort(deviceService.getDevice(deviceId));
        if (uplinkPort == null) {
            log.warn(NO_UPLINK_PORT, deviceId);
            return false;
        }

        SubscriberAndDeviceInformation prgSub = programmedSubs.get(connectPoint);
        if (prgSub != null) {
            log.warn("Subscriber {} on connectionPoint {} was previously programmed .. "
                    + "taking no action. Note that updating a subscribers params "
                    + "(vlans, bw, tpid etc) requires removing the subscriber"
                    + "before re-provisioning the subscriber", prgSub.id(),
                     connectPoint);
            return true;
        }

        //delete Eapol authentication flow with default bandwidth
        //wait until Eapol rule with defaultBpId is removed to install subscriber-based rules
        CompletableFuture<ObjectiveError> filterFuture = new CompletableFuture();
        processEapolFilteringObjectives(deviceId, subscriberPortNo, defaultBpId, filterFuture,
                VlanId.vlanId(EAPOL_DEFAULT_VLAN), false);
        // do not remove meter from bpInfoToMeter mapping as flows for other ONUs
        // could still be using it - this also prevents duplicate meters from being
        // created for the same bandwidth profile
        // we still need to remove from programmedMeters so the meter can be
        // deleted if its reference count drops to zero
        removeMeterIdFromPrgMeters(deviceId, defaultBpId);

        //install subscriber flows
        filterFuture.thenAcceptAsync(filterStatus -> {
            if (filterStatus == null) {
                provisionSubscriberBasedFlows(connectPoint, uplinkPort.number(), Optional.empty(), sub);
            }
        });

        // cache subscriber info
        programmedSubs.put(connectPoint, sub);
        return true;
    }

    @Override
    public boolean removeSubscriber(ConnectPoint connectPoint) {
        log.info("Call to un-provision subscriber at {}", connectPoint);

        // Get the subscriber connected to this port from the local cache
        // If we don't know about the subscriber there's no need to remove it
        DeviceId deviceId = connectPoint.deviceId();
        PortNumber subscriberPortNo = connectPoint.port();

        SubscriberAndDeviceInformation subscriber = programmedSubs.get(connectPoint);
        if (subscriber == null) {
            log.warn("Subscriber on connectionPoint {} was not previously programmed, " +
                    "no need to remove it", connectPoint);
            return true;
        }

        // Get the uplink port
        Port uplinkPort = getUplinkPort(deviceService.getDevice(deviceId));
        if (uplinkPort == null) {
            log.warn(NO_UPLINK_PORT, deviceId);
            return false;
        }

        //delete dhcp & igmp trap flows
        MeterId upstreamMeterId = getMeterIdFromBpMapping(deviceId, subscriber.upstreamBandwidthProfile());

        // remove dhcp filters
        processDhcpFilteringObjectives(deviceId, subscriberPortNo,
                upstreamMeterId, subscriber.technologyProfileId(), false, true);

        // remove igmp filters
        processIgmpFilteringObjectives(deviceId, subscriberPortNo,
                upstreamMeterId, subscriber.technologyProfileId(), false);

        //unprovision vlans
        unprovisionVlans(deviceId, uplinkPort.number(), subscriberPortNo, subscriber, Optional.empty());

        // Remove if there are any flows for the additional Vlans
        Collection<? extends Map.Entry<VlanId, VlanId>> vlansList = additionalVlans.get(connectPoint).value();

        // Remove the flows for the additional vlans for this subscriber
        for (Map.Entry<VlanId, VlanId> vlans : vlansList) {
            unprovisionTransparentFlows(deviceId, uplinkPort.number(), subscriberPortNo,
                    vlans.getValue(), vlans.getKey());

            // Remove it from the map also
            additionalVlans.remove(connectPoint, vlans);
        }

        // re-install eapol with default bandwidth profile
        processEapolFilteringObjectives(deviceId, subscriberPortNo,
                subscriber.upstreamBandwidthProfile(), null, subscriber.cTag(), false);

        Port port = deviceService.getPort(deviceId, subscriberPortNo);
        if (port != null && port.isEnabled()) {
            processEapolFilteringObjectives(deviceId, subscriberPortNo, defaultBpId,
                    null, VlanId.vlanId(EAPOL_DEFAULT_VLAN), true);
        } else {
            log.debug("Port {} is no longer enabled or it's unavailable. Not "
                    + "reprogramming default eapol flow", connectPoint);
        }

        programmedSubs.remove(connectPoint);
        return true;
    }

    @Override
    public boolean provisionSubscriber(AccessSubscriberId subscriberId, Optional<VlanId> sTag, Optional<VlanId> cTag) {

        log.info("Provisioning subscriber using subscriberId {}, sTag {}, cTag {}", subscriberId, sTag, cTag);

        // Check if we can find the connect point to which this subscriber is connected
        ConnectPoint subsPort = findSubscriberConnectPoint(subscriberId.toString());
        if (subsPort == null) {
            log.warn("ConnectPoint for {} not found", subscriberId);
            return false;
        }

        if (!sTag.isPresent() && !cTag.isPresent()) {
            return provisionSubscriber(subsPort);
        } else if (sTag.isPresent() && cTag.isPresent()) {
            Port uplinkPort = getUplinkPort(deviceService.getDevice(subsPort.deviceId()));
            if (uplinkPort == null) {
                log.warn(NO_UPLINK_PORT, subsPort.deviceId());
                return false;
            }

            CompletableFuture<ObjectiveError> filterFuture = new CompletableFuture();

            //delete Eapol authentication flow with default bandwidth
            //wait until Eapol rule with defaultBpId is removed to install subscriber-based rules
            processEapolFilteringObjectives(subsPort.deviceId(), subsPort.port(), defaultBpId, filterFuture,
                    VlanId.vlanId(EAPOL_DEFAULT_VLAN), false);
            // do not remove meter from bpInfoToMeter mapping as flows for other ONUs
            // could still be using it - this also prevents duplicate meters from being
            // created for the same bandwidth profile
            // we still need to remove from programmedMeters so the meter can be
            // deleted if its reference count drops to zero
            removeMeterIdFromPrgMeters(subsPort.deviceId(), defaultBpId);

            //install subscriber flows
            filterFuture.thenAcceptAsync(filterStatus -> {
                if (filterStatus == null) {
                    provisionTransparentFlows(subsPort.deviceId(), uplinkPort.number(), subsPort.port(),
                            cTag.get(), sTag.get());
                }
            });
            return true;
        } else {
            log.warn("Provisioning failed for subscriber: {}", subscriberId);
            return false;
        }
    }

    @Override
    public boolean removeSubscriber(AccessSubscriberId subscriberId, Optional<VlanId> sTag, Optional<VlanId> cTag) {
        // Check if we can find the connect point to which this subscriber is connected
        ConnectPoint subsPort = findSubscriberConnectPoint(subscriberId.toString());
        if (subsPort == null) {
            log.warn("ConnectPoint for {} not found", subscriberId);
            return false;
        }

        if (!sTag.isPresent() && !cTag.isPresent()) {
            return removeSubscriber(subsPort);
        } else if (sTag.isPresent() && cTag.isPresent()) {
            // Get the uplink port
            Port uplinkPort = getUplinkPort(deviceService.getDevice(subsPort.deviceId()));
            if (uplinkPort == null) {
                log.warn(NO_UPLINK_PORT, subsPort.deviceId());
                return false;
            }

            unprovisionTransparentFlows(subsPort.deviceId(), uplinkPort.number(), subsPort.port(),
                    cTag.get(), sTag.get());

            programmedSubs.remove(subsPort);

            return true;
        } else {
            log.warn("Removing subscriber failed for: {}", subscriberId);
            return false;
        }
    }

    @Override
    public Collection<Map.Entry<ConnectPoint, Map.Entry<VlanId, VlanId>>> getSubscribers() {
        ArrayList<Map.Entry<ConnectPoint, Map.Entry<VlanId, VlanId>>> subs = new ArrayList<>();

        // Get the subscribers for all the devices configured in sadis
        // If the port is UNI, is enabled and exists in Sadis then copy it
        for (Device d : deviceService.getDevices()) {
            if (getOltInfo(d) == null) {
                continue; // not an olt, or not configured in sadis
            }
            for (Port p : deviceService.getPorts(d.id())) {
                if (isUniPort(d, p) && p.isEnabled()) {
                    ConnectPoint cp = new ConnectPoint(d.id(), p.number());

                    SubscriberAndDeviceInformation sub = getSubscriber(cp);
                    if (sub != null) {
                        Map.Entry<VlanId, VlanId> vlans = new AbstractMap.SimpleEntry(sub.sTag(), sub.cTag());
                        subs.add(new AbstractMap.SimpleEntry(cp, vlans));
                    }
                }
            }
        }

        return subs;
    }

    @Override
    public ImmutableMap<ConnectPoint, SubscriberAndDeviceInformation> getProgSubs() {
        return ImmutableMap.copyOf(programmedSubs);
    }

    @Override
    public ImmutableSet<MeterKey> getProgMeters() {
        return ImmutableSet.copyOf(programmedMeters);
    }

    @Override
    public ImmutableMap<String, List<MeterKey>> getBpMeterMappings() {
        return ImmutableMap.copyOf(bpInfoToMeter);
    }

    @Override
    public List<DeviceId> fetchOlts() {
        // look through all the devices and find the ones that are OLTs as per Sadis
        List<DeviceId> olts = new ArrayList<>();
        Iterable<Device> devices = deviceService.getDevices();
        for (Device d : devices) {
            if (getOltInfo(d) != null) {
                // So this is indeed an OLT device
                olts.add(d.id());
            }
        }
        return olts;
    }

    /**
     * Finds the connect point to which a subscriber is connected.
     *
     * @param id The id of the subscriber, this is the same ID as in Sadis
     * @return Subscribers ConnectPoint if found else null
     */
    private ConnectPoint findSubscriberConnectPoint(String id) {

        Iterable<Device> devices = deviceService.getDevices();
        for (Device d : devices) {
            for (Port p : deviceService.getPorts(d.id())) {
                log.trace("Comparing {} with {}", p.annotations().value(AnnotationKeys.PORT_NAME), id);
                if (p.annotations().value(AnnotationKeys.PORT_NAME).equals(id)) {
                    log.debug("Found on device {} port {}", d.id(), p.number());
                    return new ConnectPoint(d.id(), p.number());
                }
            }
        }
        return null;
    }

    private BandwidthProfileInformation getBandwidthProfileInformation(String bandwidthProfile) {
        if (bandwidthProfile == null) {
            return null;
        }
        return bpService.get(bandwidthProfile);
    }

    /**
     * Removes subscriber vlan flows.
     *
     * @param deviceId       the device identifier
     * @param uplink         uplink port of the OLT
     * @param subscriberPort uni port
     * @param subscriber     subscriber info that includes s, c tags, tech profile and bandwidth profile references
     * @param defaultVlan    default vlan of the subscriber
     */
    private void unprovisionVlans(DeviceId deviceId, PortNumber uplink,
                                  PortNumber subscriberPort, SubscriberAndDeviceInformation subscriber,
                                  Optional<VlanId> defaultVlan) {
        log.info("Unprovisioning vlans for subscriber {} on dev/port: {}/{}",
                 subscriber, deviceId, subscriberPort);

        CompletableFuture<ObjectiveError> downFuture = new CompletableFuture();
        CompletableFuture<ObjectiveError> upFuture = new CompletableFuture();

        VlanId deviceVlan = subscriber.sTag();
        VlanId subscriberVlan = subscriber.cTag();

        MeterId upstreamMeterId = getMeterIdFromBpMapping(deviceId, subscriber.upstreamBandwidthProfile());
        MeterId downstreamMeterId = getMeterIdFromBpMapping(deviceId, subscriber.downstreamBandwidthProfile());

        ForwardingObjective.Builder upFwd = upBuilder(uplink, subscriberPort,
                subscriberVlan, deviceVlan,
                defaultVlan, upstreamMeterId, subscriber.technologyProfileId());
        ForwardingObjective.Builder downFwd = downBuilder(uplink, subscriberPort,
                subscriberVlan, deviceVlan,
                defaultVlan, downstreamMeterId, subscriber.technologyProfileId());

        flowObjectiveService.forward(deviceId, upFwd.remove(new ObjectiveContext() {
            @Override
            public void onSuccess(Objective objective) {
                upFuture.complete(null);
            }

            @Override
            public void onError(Objective objective, ObjectiveError error) {
                upFuture.complete(error);
            }
        }));

        flowObjectiveService.forward(deviceId, downFwd.remove(new ObjectiveContext() {
            @Override
            public void onSuccess(Objective objective) {
                downFuture.complete(null);
            }

            @Override
            public void onError(Objective objective, ObjectiveError error) {
                downFuture.complete(error);
            }
        }));

        upFuture.thenAcceptBothAsync(downFuture, (upStatus, downStatus) -> {
            if (upStatus == null && downStatus == null) {
                post(new AccessDeviceEvent(AccessDeviceEvent.Type.SUBSCRIBER_UNREGISTERED,
                        deviceId,
                        deviceVlan,
                        subscriberVlan));
            } else if (downStatus != null) {
                log.error("Subscriber with vlan {} on device {} " +
                                "on port {} failed downstream uninstallation: {}",
                        subscriberVlan, deviceId, subscriberPort, downStatus);
            } else if (upStatus != null) {
                log.error("Subscriber with vlan {} on device {} " +
                                "on port {} failed upstream uninstallation: {}",
                        subscriberVlan, deviceId, subscriberPort, upStatus);
            }
        }, oltInstallers);

        programmedMeters.remove(MeterKey.key(deviceId, upstreamMeterId));
        programmedMeters.remove(MeterKey.key(deviceId, downstreamMeterId));
        log.debug("programmed Meters size {}", programmedMeters.size());
    }

    /**
     * Adds subscriber vlan flows, dhcp, eapol and igmp trap flows for the related uni port.
     *
     * @param port        the connection point of the subscriber
     * @param uplinkPort  uplink port of the OLT
     * @param defaultVlan default vlan of the subscriber
     * @param sub         subscriber information that includes s, c tags, tech profile and bandwidth profile references
     */
    private void provisionSubscriberBasedFlows(ConnectPoint port, PortNumber uplinkPort,
                                               Optional<VlanId> defaultVlan,
                                               SubscriberAndDeviceInformation sub) {

        log.info("Provisioning vlans for subscriber {} on dev/port: {}",
                 sub, port);

        DeviceId deviceId = port.deviceId();
        PortNumber subscriberPort = port.port();
        VlanId deviceVlan = sub.sTag();
        VlanId subscriberVlan = sub.cTag();
        int techProfId = sub.technologyProfileId();

        BandwidthProfileInformation upstreamBpInfo = getBandwidthProfileInformation(sub.upstreamBandwidthProfile());
        BandwidthProfileInformation downstreamBpInfo = getBandwidthProfileInformation(sub.downstreamBandwidthProfile());

        CompletableFuture<ObjectiveError> downFuture = new CompletableFuture();
        CompletableFuture<ObjectiveError> upFuture = new CompletableFuture();
        CompletableFuture<Object> upstreamMeterFuture = new CompletableFuture<>();
        CompletableFuture<Object> downsteamMeterFuture = new CompletableFuture<>();

        MeterId upstreamMeterId = createMeter(deviceId, upstreamBpInfo, upstreamMeterFuture);
        MeterId downstreamMeterId = createMeter(deviceId, downstreamBpInfo, downsteamMeterFuture);

        //install upstream flows
        upstreamMeterFuture.thenAcceptAsync(result -> {
            if (result == null) {
                log.info("Upstream Meter {} is in the device {}. " +
                        "Sending subscriber flows.", upstreamMeterId, deviceId);
                ForwardingObjective.Builder upFwd = upBuilder(uplinkPort, subscriberPort,
                        subscriberVlan, deviceVlan,
                        defaultVlan, upstreamMeterId, techProfId);


                flowObjectiveService.forward(deviceId, upFwd.add(new ObjectiveContext() {
                    @Override
                    public void onSuccess(Objective objective) {
                        upFuture.complete(null);
                    }

                    @Override
                    public void onError(Objective objective, ObjectiveError error) {
                        upFuture.complete(error);
                    }
                }));
            } else {
                log.warn("Meter installation error while sending upstream flows. " +
                        "Result {} and MeterId {}", result, upstreamMeterId);
            }
        });

        //install downstream flows
        downsteamMeterFuture.thenAcceptAsync(result -> {
            if (result == null) {
                log.info("Downstream Meter {} is in the device {}. " +
                        "Sending subscriber flows.", downstreamMeterId, deviceId);
                ForwardingObjective.Builder downFwd = downBuilder(uplinkPort, subscriberPort,
                        subscriberVlan, deviceVlan,
                        defaultVlan, downstreamMeterId, techProfId);

                flowObjectiveService.forward(deviceId, downFwd.add(new ObjectiveContext() {
                    @Override
                    public void onSuccess(Objective objective) {
                        downFuture.complete(null);
                    }

                    @Override
                    public void onError(Objective objective, ObjectiveError error) {
                        downFuture.complete(error);
                    }
                }));
            } else {
                log.warn("Meter installation error while sending downstream flows. " +
                        "Result {} and MeterId {}", result, downstreamMeterId);
            }
        });

        //send eapol & dhcp & igmp flows
        //send Subscriber Registered event
        upFuture.thenAcceptBothAsync(downFuture, (upStatus, downStatus) -> {
            if (upStatus == null && downStatus == null) {

                if (upstreamMeterId != null) {
                    //re-install Eapol authentication flow with the subscribers' upstream bandwidth profile
                    processEapolFilteringObjectives(deviceId, subscriberPort, sub.upstreamBandwidthProfile(),
                            null, sub.cTag(), true);

                    processDhcpFilteringObjectives(deviceId, subscriberPort,
                            upstreamMeterId, sub.technologyProfileId(), true, true);

                    processIgmpFilteringObjectives(deviceId, subscriberPort,
                            upstreamMeterId, sub.technologyProfileId(), true);
                }

                post(new AccessDeviceEvent(AccessDeviceEvent.Type.SUBSCRIBER_REGISTERED,
                        deviceId,
                        deviceVlan,
                        subscriberVlan));

            } else if (downStatus != null) {
                log.error("Subscriber with vlan {} on device {} " +
                                "on port {} failed downstream installation: {}",
                        subscriberVlan, deviceId, subscriberPort, downStatus);
            } else if (upStatus != null) {
                log.error("Subscriber with vlan {} on device {} " +
                                "on port {} failed upstream installation: {}",
                        subscriberVlan, deviceId, subscriberPort, upStatus);
            }
        }, oltInstallers);
    }

    private MeterId createMeter(DeviceId deviceId, BandwidthProfileInformation bpInfo,
                                CompletableFuture<Object> meterFuture) {
        if (bpInfo == null) {
            log.warn("Bandwidth profile information cannot be null when creating meter");
            return null;
        }

        MeterId meterId = getMeterIdFromBpMapping(deviceId, bpInfo.id());
        if (meterId != null) {
            log.debug("Meter {} was previously created for bp {}", meterId,
                     bpInfo.id());
            meterFuture.complete(null);
            return meterId;
        }

        List<Band> meterBands = createMeterBands(bpInfo);

        MeterRequest meterRequest = DefaultMeterRequest.builder()
                .withBands(meterBands)
                .withUnit(Meter.Unit.KB_PER_SEC)
                .withContext(new MeterContext() {
                    @Override
                    public void onSuccess(MeterRequest op) {
                        log.debug("meter addition confirmed for bpInfo:{}", bpInfo);
                        meterFuture.complete(null);
                    }

                    @Override
                    public void onError(MeterRequest op, MeterFailReason reason) {
                        meterFuture.complete(reason);
                    }
                })
                .forDevice(deviceId)
                .fromApp(appId)
                .burst()
                .add();

        Meter meter = meterService.submit(meterRequest);
        addMeterIdToBpMapping(deviceId, meter.id(), bpInfo.id());
        log.info("Meter creation message sent for Meter Id {}", meter.id());
        programmedMeters.add(MeterKey.key(deviceId, meter.id()));
        return meter.id();
    }

    private List<Band> createMeterBands(BandwidthProfileInformation bpInfo) {
        List<Band> meterBands = new ArrayList<>();

        meterBands.add(createMeterBand(bpInfo.committedInformationRate(), bpInfo.committedBurstSize()));
        meterBands.add(createMeterBand(bpInfo.exceededInformationRate(), bpInfo.exceededBurstSize()));
        meterBands.add(createMeterBand(bpInfo.assuredInformationRate(), 0L));

        return meterBands;
    }

    private Band createMeterBand(long rate, Long burst) {
        return DefaultBand.builder()
                .withRate(rate) //already Kbps
                .burstSize(burst) // already Kbits
                .ofType(Band.Type.DROP) // no matter
                .build();
    }

    private ForwardingObjective.Builder downBuilder(PortNumber uplinkPort,
                                                    PortNumber subscriberPort,
                                                    VlanId subscriberVlan,
                                                    VlanId deviceVlan,
                                                    Optional<VlanId> defaultVlan,
                                                    MeterId meterId,
                                                    int techProfId) {
        TrafficSelector downstream = DefaultTrafficSelector.builder()
                .matchVlanId(deviceVlan)
                .matchInPort(uplinkPort)
                .matchInnerVlanId(subscriberVlan)
                .build();

        TrafficTreatment.Builder downstreamTreatmentBuilder = DefaultTrafficTreatment.builder()
                .popVlan()
                .setVlanId(defaultVlan.orElse(VlanId.vlanId((short) this.defaultVlan)))
                .setOutput(subscriberPort);

        if (meterId != null) {
            downstreamTreatmentBuilder.meter(meterId);
        }

        downstreamTreatmentBuilder.writeMetadata(createMetadata(subscriberVlan, techProfId, subscriberPort), 0);

        return DefaultForwardingObjective.builder()
                .withFlag(ForwardingObjective.Flag.VERSATILE)
                .withPriority(1000)
                .makePermanent()
                .withSelector(downstream)
                .fromApp(appId)
                .withTreatment(downstreamTreatmentBuilder.build());
    }

    private ForwardingObjective.Builder upBuilder(PortNumber uplinkPort,
                                                  PortNumber subscriberPort,
                                                  VlanId subscriberVlan,
                                                  VlanId deviceVlan,
                                                  Optional<VlanId> defaultVlan,
                                                  MeterId meterId,
                                                  int technologyProfileId) {


        VlanId dVlan = defaultVlan.orElse(VlanId.vlanId((short) this.defaultVlan));

        if (subscriberVlan.toShort() == 4096) {
            dVlan = subscriberVlan;
        }

        TrafficSelector upstream = DefaultTrafficSelector.builder()
                .matchVlanId(dVlan)
                .matchInPort(subscriberPort)
                .build();


        TrafficTreatment.Builder upstreamTreatmentBuilder = DefaultTrafficTreatment.builder()
                .pushVlan()
                .setVlanId(subscriberVlan)
                .pushVlan()
                .setVlanId(deviceVlan)
                .setOutput(uplinkPort);

        if (meterId != null) {
            upstreamTreatmentBuilder.meter(meterId);
        }

        upstreamTreatmentBuilder.writeMetadata(createMetadata(deviceVlan, technologyProfileId, uplinkPort), 0L);

        return DefaultForwardingObjective.builder()
                .withFlag(ForwardingObjective.Flag.VERSATILE)
                .withPriority(1000)
                .makePermanent()
                .withSelector(upstream)
                .fromApp(appId)
                .withTreatment(upstreamTreatmentBuilder.build());
    }

    private void provisionTransparentFlows(DeviceId deviceId, PortNumber uplinkPort,
                                           PortNumber subscriberPort,
                                           VlanId innerVlan,
                                           VlanId outerVlan) {

        ConnectPoint cp = new ConnectPoint(deviceId, subscriberPort);

        SubscriberAndDeviceInformation subInfo = getSubscriber(cp);

        BandwidthProfileInformation upstreamBpInfo = getBandwidthProfileInformation(
                subInfo.upstreamBandwidthProfile());
        BandwidthProfileInformation downstreamBpInfo = getBandwidthProfileInformation(
                subInfo.downstreamBandwidthProfile());

        CompletableFuture<Object> upstreamMeterFuture = new CompletableFuture<>();
        CompletableFuture<Object> downsteamMeterFuture = new CompletableFuture<>();
        CompletableFuture<ObjectiveError> upFuture = new CompletableFuture();
        CompletableFuture<ObjectiveError> downFuture = new CompletableFuture();

        MeterId upstreamMeterId = createMeter(deviceId, upstreamBpInfo, upstreamMeterFuture);
        MeterId downstreamMeterId = createMeter(deviceId, downstreamBpInfo, downsteamMeterFuture);

        upstreamMeterFuture.thenAcceptAsync(result -> {
            if (result == null) {
                log.info("Upstream Meter {} is sent to the device {}. " +
                        "Sending subscriber flows.", upstreamMeterId, deviceId);

                ForwardingObjective.Builder upFwd = transparentUpBuilder(uplinkPort, subscriberPort,
                        innerVlan, outerVlan, upstreamMeterId, subInfo);

                flowObjectiveService.forward(deviceId, upFwd.add(new ObjectiveContext() {
                    @Override
                    public void onSuccess(Objective objective) {
                        upFuture.complete(null);
                    }

                    @Override
                    public void onError(Objective objective, ObjectiveError error) {
                        upFuture.complete(error);
                    }
                }));

            } else {
                log.warn("Meter installation error while sending upstream flows. " +
                        "Result {} and MeterId {}", result, upstreamMeterId);
            }
        });

        downsteamMeterFuture.thenAcceptAsync(result -> {
            if (result == null) {
                log.info("Downstream Meter {} is sent to the device {}. " +
                        "Sending subscriber flows.", downstreamMeterId, deviceId);

                ForwardingObjective.Builder downFwd = transparentDownBuilder(uplinkPort, subscriberPort,
                        innerVlan, outerVlan, downstreamMeterId, subInfo);

                flowObjectiveService.forward(deviceId, downFwd.add(new ObjectiveContext() {
                    @Override
                    public void onSuccess(Objective objective) {
                        downFuture.complete(null);
                    }

                    @Override
                    public void onError(Objective objective, ObjectiveError error) {
                        downFuture.complete(error);
                    }
                }));
            } else {
                log.warn("Meter installation error while sending upstream flows. " +
                        "Result {} and MeterId {}", result, downstreamMeterId);
            }
        });

        additionalVlans.put(cp, new AbstractMap.SimpleEntry(outerVlan, innerVlan));

        upFuture.thenAcceptBothAsync(downFuture, (upStatus, downStatus) -> {
            if (downStatus != null) {
                log.error("Flow with innervlan {} and outerVlan {} on device {} " +
                                "on port {} failed downstream installation: {}",
                        innerVlan, outerVlan, deviceId, cp, downStatus);
            } else if (upStatus != null) {
                log.error("Flow with innerVlan {} and outerVlan {} on device {} " +
                                "on port {} failed upstream installation: {}",
                        innerVlan, outerVlan, deviceId, cp, upStatus);
            } else {
                processEapolFilteringObjectives(deviceId, subscriberPort, subInfo.upstreamBandwidthProfile(),
                        null, subInfo.cTag(), true);

                // cache subscriber info
                programmedSubs.put(cp, subInfo);
            }
        }, oltInstallers);

    }

    private ForwardingObjective.Builder transparentDownBuilder(PortNumber uplinkPort,
                                                               PortNumber subscriberPort,
                                                               VlanId innerVlan,
                                                               VlanId outerVlan,
                                                               MeterId downstreamMeterId,
                                                               SubscriberAndDeviceInformation subInfo) {
        TrafficSelector downstream = DefaultTrafficSelector.builder()
                .matchVlanId(outerVlan)
                .matchInPort(uplinkPort)
                .matchInnerVlanId(innerVlan)
                .build();

        TrafficTreatment.Builder tBuilder = DefaultTrafficTreatment.builder();
        if (downstreamMeterId != null) {
            tBuilder.meter(downstreamMeterId);
        }

        TrafficTreatment downstreamTreatment = tBuilder
                .setOutput(subscriberPort)
                .writeMetadata(createMetadata(subInfo.cTag(), subInfo.technologyProfileId(), subscriberPort), 0)
                .build();

        return DefaultForwardingObjective.builder()
                .withFlag(ForwardingObjective.Flag.VERSATILE)
                .withPriority(1000)
                .makePermanent()
                .withSelector(downstream)
                .fromApp(appId)
                .withTreatment(downstreamTreatment);
    }

    private ForwardingObjective.Builder transparentUpBuilder(PortNumber uplinkPort,
                                                             PortNumber subscriberPort,
                                                             VlanId innerVlan,
                                                             VlanId outerVlan,
                                                             MeterId upstreamMeterId,
                                                             SubscriberAndDeviceInformation subInfo) {

        TrafficSelector upstream = DefaultTrafficSelector.builder()
                .matchVlanId(outerVlan)
                .matchInPort(subscriberPort)
                .matchInnerVlanId(innerVlan)
                .build();

        TrafficTreatment.Builder tBuilder = DefaultTrafficTreatment.builder();
        if (upstreamMeterId != null) {
            tBuilder.meter(upstreamMeterId);
        }

        TrafficTreatment upstreamTreatment = tBuilder
                .setOutput(uplinkPort)
                .writeMetadata(createMetadata(subInfo.sTag(), subInfo.technologyProfileId(), uplinkPort), 0)
                .build();

        return DefaultForwardingObjective.builder()
                .withFlag(ForwardingObjective.Flag.VERSATILE)
                .withPriority(1000)
                .makePermanent()
                .withSelector(upstream)
                .fromApp(appId)
                .withTreatment(upstreamTreatment);
    }

    private void unprovisionTransparentFlows(DeviceId deviceId, PortNumber uplink,
                                             PortNumber subscriberPort, VlanId innerVlan,
                                             VlanId outerVlan) {

        ConnectPoint cp = new ConnectPoint(deviceId, subscriberPort);

        SubscriberAndDeviceInformation subInfo = programmedSubs.get(cp);
        if (subInfo == null) {
            log.warn("Subscriber is not programmed before for the connectPoint {}", cp);
            return;
        }

        additionalVlans.remove(cp, new AbstractMap.SimpleEntry(outerVlan, innerVlan));

        CompletableFuture<ObjectiveError> downFuture = new CompletableFuture();
        CompletableFuture<ObjectiveError> upFuture = new CompletableFuture();

        MeterId upstreamMeterId = getMeterIdFromBpMapping(deviceId, subInfo.upstreamBandwidthProfile());
        MeterId downstreamMeterId = getMeterIdFromBpMapping(deviceId, subInfo.downstreamBandwidthProfile());

        ForwardingObjective.Builder upFwd = transparentUpBuilder(uplink, subscriberPort,
                innerVlan, outerVlan, upstreamMeterId, subInfo);
        ForwardingObjective.Builder downFwd = transparentDownBuilder(uplink, subscriberPort,
                innerVlan, outerVlan, downstreamMeterId, subInfo);

        flowObjectiveService.forward(deviceId, upFwd.remove(new ObjectiveContext() {
            @Override
            public void onSuccess(Objective objective) {
                upFuture.complete(null);
            }

            @Override
            public void onError(Objective objective, ObjectiveError error) {
                upFuture.complete(error);
            }
        }));

        flowObjectiveService.forward(deviceId, downFwd.remove(new ObjectiveContext() {
            @Override
            public void onSuccess(Objective objective) {
                downFuture.complete(null);
            }

            @Override
            public void onError(Objective objective, ObjectiveError error) {
                downFuture.complete(error);
            }
        }));

        upFuture.thenAcceptBothAsync(downFuture, (upStatus, downStatus) -> {
            if (downStatus != null) {
                log.error("Flow with innerVlan {} and outerVlan {} on device {} " +
                                "on port {} failed downstream uninstallation: {}",
                        innerVlan, outerVlan, deviceId, subscriberPort, downStatus);
            } else if (upStatus != null) {
                log.error("Flow with innerVlan {} and outerVlan {} on device {} " +
                                "on port {} failed upstream uninstallation: {}",
                        innerVlan, outerVlan, deviceId, subscriberPort, upStatus);
            }
        }, oltInstallers);

        //re-install eapol
        processEapolFilteringObjectives(deviceId, subscriberPort,
                subInfo.upstreamBandwidthProfile(), null, subInfo.cTag(), false);
        processEapolFilteringObjectives(deviceId, subscriberPort, defaultBpId,
                null, VlanId.vlanId(EAPOL_DEFAULT_VLAN), true);

        programmedMeters.remove(MeterKey.key(deviceId, upstreamMeterId));
        programmedMeters.remove(MeterKey.key(deviceId, downstreamMeterId));
    }

    private int getDefaultTechProfileId(DeviceId devId, PortNumber portNumber) {
        Port port = deviceService.getPort(devId, portNumber);
        if (port != null) {
            SubscriberAndDeviceInformation info = subsService.get(port.annotations().value(AnnotationKeys.PORT_NAME));
            if (info != null && info.technologyProfileId() != -1) {
                return info.technologyProfileId();
            }
        }
        return defaultTechProfileId;
    }

    /**
     * Returns the write metadata value including tech profile reference and innerVlan.
     * For param cVlan, null can be sent
     *
     * @param cVlan         c (customer) tag of one subscriber
     * @param techProfileId tech profile id of one subscriber
     * @return the write metadata value including tech profile reference and innerVlan
     */
    private Long createTechProfValueForWm(VlanId cVlan, int techProfileId) {
        if (cVlan == null) {
            return (long) techProfileId << 32;
        }
        return ((long) (cVlan.id()) << 48 | (long) techProfileId << 32);
    }

    /**
     * Trap eapol authentication packets to the controller.
     *
     * @param devId        the device identifier
     * @param portNumber   the port for which this trap flow is designated
     * @param bpId         bandwidth profile id to add the related meter to the flow
     * @param filterFuture completable future for this filtering objective operation
     * @param vlanId       the default or customer tag for a subscriber
     * @param install      true to install the flow, false to remove the flow
     */
    private void processEapolFilteringObjectives(DeviceId devId, PortNumber portNumber, String bpId,
                                                 CompletableFuture<ObjectiveError> filterFuture,
                                                 VlanId vlanId, boolean install) {
        if (!enableEapol) {
            log.debug("Eapol filtering is disabled.");
            if (filterFuture != null) {
                filterFuture.complete(null);
            }
            return;
        }

        if (!mastershipService.isLocalMaster(devId)) {
            return;
        }
        DefaultFilteringObjective.Builder builder = DefaultFilteringObjective.builder();
        TrafficTreatment.Builder treatmentBuilder = DefaultTrafficTreatment.builder();
        CompletableFuture<Object> meterFuture = new CompletableFuture<>();

        BandwidthProfileInformation bpInfo = getBandwidthProfileInformation(bpId);
        if (bpInfo == null) {
            log.warn("Bandwidth profile {} is not found. Authentication flow"
                    + " will not be installed", bpId);
            return;
        }

        // check if meter exists and create it only for an install
        MeterId meterId = getMeterIdFromBpMapping(devId, bpInfo.id());
        if (meterId == null) {
            if (install) {
                meterId = createMeter(devId, bpInfo, meterFuture);
                treatmentBuilder.meter(meterId);
            } else {
                // this case should not happen as the request to remove an eapol
                // flow should mean that the flow points to a meter that exists.
                // Nevertheless we can still delete the flow as we only need the
                // correct 'match' to do so.
                log.warn("Unknown meter id for bp {}, still proceeding with "
                        + "delete of eapol flow for {}/{}", bpInfo.id(), devId,
                         portNumber);
                meterFuture.complete(null);
            }
        } else {
            log.debug("Meter {} was previously created for bp {}", meterId,
                      bpInfo.id());
            treatmentBuilder.meter(meterId);
            meterFuture.complete(null);
        }

        final MeterId mId = meterId;
        meterFuture.thenAcceptAsync(result -> {
            if (result == null) {
                log.info("Meter {} for {} on {}/{} exists. {} EAPOL trap flow",
                         mId, bpId, devId, portNumber,
                        (install) ? "Installing " : "Removing ");
                int techProfileId = getDefaultTechProfileId(devId, portNumber);

                //Authentication trap flow uses only tech profile id as write metadata value
                FilteringObjective eapol = (install ? builder.permit() : builder.deny())
                        .withKey(Criteria.matchInPort(portNumber))
                        .addCondition(Criteria.matchEthType(EthType.EtherType.EAPOL.ethType()))
                        .addCondition(Criteria.matchVlanId(vlanId))
                        .withMeta(treatmentBuilder
                                .writeMetadata(createTechProfValueForWm(vlanId, techProfileId), 0)
                                .setOutput(PortNumber.CONTROLLER).build())
                        .fromApp(appId)
                        .withPriority(10000)
                        .add(new ObjectiveContext() {
                            @Override
                            public void onSuccess(Objective objective) {
                                log.info("Eapol filter for {} on {} {} with meter {}.",
                                        devId, portNumber, (install) ? INSTALLED : REMOVED, mId);
                                if (filterFuture != null) {
                                    filterFuture.complete(null);
                                }
                            }

                            @Override
                            public void onError(Objective objective, ObjectiveError error) {
                                log.info("Eapol filter for {} on {} with meter {} failed {} because {}",
                                        devId, portNumber, mId, (install) ? INSTALLATION : REMOVAL,
                                        error);
                                if (filterFuture != null) {
                                    filterFuture.complete(error);
                                }
                            }
                        });

                flowObjectiveService.filter(devId, eapol);
            } else {
                log.warn("Meter installation error while sending eapol trap flow. " +
                        "Result {} and MeterId {}", result, mId);
            }
        });
    }

    /**
     * Installs trap filtering objectives for particular traffic types on an
     * NNI port.
     *
     * @param devId   device ID
     * @param port    port number
     * @param install true to install, false to remove
     */
    private void processNniFilteringObjectives(DeviceId devId, PortNumber port, boolean install) {
        processLldpFilteringObjective(devId, port, install);
        processDhcpFilteringObjectives(devId, port, null, -1, install, false);
    }

    private void processLldpFilteringObjective(DeviceId devId, PortNumber port, boolean install) {
        if (!mastershipService.isLocalMaster(devId)) {
            return;
        }
        DefaultFilteringObjective.Builder builder = DefaultFilteringObjective.builder();

        FilteringObjective lldp = (install ? builder.permit() : builder.deny())
                .withKey(Criteria.matchInPort(port))
                .addCondition(Criteria.matchEthType(EthType.EtherType.LLDP.ethType()))
                .withMeta(DefaultTrafficTreatment.builder()
                        .setOutput(PortNumber.CONTROLLER).build())
                .fromApp(appId)
                .withPriority(10000)
                .add(new ObjectiveContext() {
                    @Override
                    public void onSuccess(Objective objective) {
                        log.info("LLDP filter for device {} on port {} {}.",
                                devId, port, (install) ? INSTALLED : REMOVED);
                    }

                    @Override
                    public void onError(Objective objective, ObjectiveError error) {
                        log.info("LLDP filter for device {} on port {} failed {} because {}",
                                devId, port, (install) ? INSTALLATION : REMOVAL,
                                error);
                    }
                });

        flowObjectiveService.filter(devId, lldp);

    }

    /**
     * Trap dhcp packets to the controller.
     *
     * @param devId           the device identifier
     * @param port            the port for which this trap flow is designated
     * @param upstreamMeterId the upstream meter id that includes the upstream
     *                        bandwidth profile values such as PIR,CIR. If no meter id needs to be referenced,
     *                        null can be sent
     * @param techProfileId   the technology profile id that is used to create write
     *                        metadata instruction value. If no tech profile id needs to be referenced,
     *                        -1 can be sent
     * @param install         true to install the flow, false to remove the flow
     * @param upstream        true if trapped packets are flowing upstream towards
     *                        server, false if packets are flowing downstream towards client
     */
    private void processDhcpFilteringObjectives(DeviceId devId, PortNumber port,
                                                MeterId upstreamMeterId,
                                                int techProfileId,
                                                boolean install,
                                                boolean upstream) {

        if (!enableDhcpOnProvisioning) {
            log.debug("Dhcp provisioning is disabled.");
            return;
        }

        if (!mastershipService.isLocalMaster(devId)) {
            return;
        }

        if (enableDhcpV4) {
            int udpSrc = (upstream) ? 68 : 67;
            int udpDst = (upstream) ? 67 : 68;

            EthType ethType = EthType.EtherType.IPV4.ethType();
            byte protocol = IPv4.PROTOCOL_UDP;

            this.addDhcpFilteringObjectives(devId, port, udpSrc, udpDst, ethType,
                    upstreamMeterId, techProfileId, protocol, install);
        }

        if (enableDhcpV6) {
            int udpSrc = (upstream) ? 547 : 546;
            int udpDst = (upstream) ? 546 : 547;

            EthType ethType = EthType.EtherType.IPV6.ethType();
            byte protocol = IPv6.PROTOCOL_UDP;

            this.addDhcpFilteringObjectives(devId, port, udpSrc, udpDst, ethType,
                    upstreamMeterId, techProfileId, protocol, install);
        }

    }

    private void addDhcpFilteringObjectives(DeviceId devId,
                                            PortNumber port,
                                            int udpSrc,
                                            int udpDst,
                                            EthType ethType,
                                            MeterId upstreamMeterId,
                                            int techProfileId,
                                            byte protocol,
                                            boolean install) {

        DefaultFilteringObjective.Builder builder = DefaultFilteringObjective.builder();
        TrafficTreatment.Builder treatmentBuilder = DefaultTrafficTreatment.builder();

        if (upstreamMeterId != null) {
            treatmentBuilder.meter(upstreamMeterId);
        }

        if (techProfileId != -1) {
            treatmentBuilder.writeMetadata(createTechProfValueForWm(null, techProfileId), 0);
        }

        FilteringObjective dhcpUpstream = (install ? builder.permit() : builder.deny())
                .withKey(Criteria.matchInPort(port))
                .addCondition(Criteria.matchEthType(ethType))
                .addCondition(Criteria.matchIPProtocol(protocol))
                .addCondition(Criteria.matchUdpSrc(TpPort.tpPort(udpSrc)))
                .addCondition(Criteria.matchUdpDst(TpPort.tpPort(udpDst)))
                .withMeta(treatmentBuilder
                        .setOutput(PortNumber.CONTROLLER).build())
                .fromApp(appId)
                .withPriority(10000)
                .add(new ObjectiveContext() {
                    @Override
                    public void onSuccess(Objective objective) {
                        log.info("DHCP {} filter for device {} on port {} {}.",
                                (ethType.equals(EthType.EtherType.IPV4.ethType())) ? "v4" : "v6",
                                devId, port, (install) ? INSTALLED : REMOVED);
                    }

                    @Override
                    public void onError(Objective objective, ObjectiveError error) {
                        log.info("DHCP {} filter for device {} on port {} failed {} because {}",
                                (ethType.equals(EthType.EtherType.IPV4.ethType())) ? "v4" : "v6",
                                devId, port, (install) ? INSTALLATION : REMOVAL,
                                error);
                    }
                });

        flowObjectiveService.filter(devId, dhcpUpstream);
    }

    private void processIgmpFilteringObjectives(DeviceId devId, PortNumber port,
                                                MeterId upstreamMeterId,
                                                int techProfileId,
                                                boolean install) {

        if (!enableIgmpOnProvisioning) {
            log.debug("Igmp provisioning is disabled.");
            return;
        }

        if (!mastershipService.isLocalMaster(devId)) {
            return;
        }

        DefaultFilteringObjective.Builder builder = DefaultFilteringObjective.builder();
        TrafficTreatment.Builder treatmentBuilder = DefaultTrafficTreatment.builder();

        if (upstreamMeterId != null) {
            treatmentBuilder.meter(upstreamMeterId);
        }

        if (techProfileId != -1) {
            treatmentBuilder.writeMetadata(createTechProfValueForWm(null, techProfileId), 0);
        }

        builder = install ? builder.permit() : builder.deny();

        FilteringObjective igmp = builder
                .withKey(Criteria.matchInPort(port))
                .addCondition(Criteria.matchEthType(EthType.EtherType.IPV4.ethType()))
                .addCondition(Criteria.matchIPProtocol(IPv4.PROTOCOL_IGMP))
                .withMeta(treatmentBuilder
                        .setOutput(PortNumber.CONTROLLER).build())
                .fromApp(appId)
                .withPriority(10000)
                .add(new ObjectiveContext() {
                    @Override
                    public void onSuccess(Objective objective) {
                        log.info("Igmp filter for {} on {} {}.",
                                devId, port, (install) ? INSTALLED : REMOVED);
                    }

                    @Override
                    public void onError(Objective objective, ObjectiveError error) {
                        log.info("Igmp filter for {} on {} failed {} because {}.",
                                devId, port, (install) ? INSTALLATION : REMOVAL,
                                error);
                    }
                });

        flowObjectiveService.filter(devId, igmp);
    }

    /**
     * Creates trap flows for device, including DHCP and LLDP trap on NNI and
     * EAPOL trap on the UNIs, if device is present in Sadis config.
     *
     * @param dev Device to look for
     */
    private void checkAndCreateDeviceFlows(Device dev) {
        // we create only for the ones we are master of
        if (!mastershipService.isLocalMaster(dev.id())) {
            return;
        }
        // check if this device is provisioned in Sadis
        SubscriberAndDeviceInformation deviceInfo = getOltInfo(dev);
        log.debug("checkAndCreateDeviceFlows: deviceInfo {}", deviceInfo);

        if (deviceInfo != null) {
            // This is an OLT device as per Sadis, we create flows for UNI and NNI ports
            for (Port p : deviceService.getPorts(dev.id())) {
                if (isUniPort(dev, p)) {
                    processEapolFilteringObjectives(dev.id(), p.number(), defaultBpId, null,
                            VlanId.vlanId(EAPOL_DEFAULT_VLAN), true);
                } else {
                    processNniFilteringObjectives(dev.id(), p.number(), true);
                }
            }
        }
    }


    /**
     * Get the uplink for of the OLT device.
     * <p>
     * This assumes that the OLT has a single uplink port. When more uplink ports need to be supported
     * this logic needs to be changed
     *
     * @param dev Device to look for
     * @return The uplink Port of the OLT
     */
    private Port getUplinkPort(Device dev) {
        // check if this device is provisioned in Sadis
        SubscriberAndDeviceInformation deviceInfo = getOltInfo(dev);
        log.trace("getUplinkPort: deviceInfo {}", deviceInfo);
        if (deviceInfo == null) {
            log.warn("Device {} is not configured in SADIS .. cannot fetch device"
                    + " info", dev.id());
            return null;
        }
        // Return the port that has been configured as the uplink port of this OLT in Sadis
        for (Port p : deviceService.getPorts(dev.id())) {
            if (p.number().toLong() == deviceInfo.uplinkPort()) {
                log.trace("getUplinkPort: Found port {}", p);
                return p;
            }
        }

        log.warn("getUplinkPort: " + NO_UPLINK_PORT, dev.id());
        return null;
    }

    /**
     * Return the subscriber on a port.
     *
     * @param cp ConnectPoint on which to find the subscriber
     * @return subscriber if found else null
     */
    SubscriberAndDeviceInformation getSubscriber(ConnectPoint cp) {
        Port port = deviceService.getPort(cp);
        checkNotNull(port, "Invalid connect point");
        String portName = port.annotations().value(AnnotationKeys.PORT_NAME);
        return subsService.get(portName);
    }

    /**
     * Write metadata instruction value (metadata) is 8 bytes.
     * <p>
     * MS 2 bytes: C Tag
     * Next 2 bytes: Technology Profile Id
     * Next 4 bytes: Port number (uni or nni)
     */

    private Long createMetadata(VlanId innerVlan, int techProfileId, PortNumber egressPort) {

        if (techProfileId == -1) {
            techProfileId = DEFAULT_TP_ID;
        }

        return ((long) (innerVlan.id()) << 48 | (long) techProfileId << 32) | egressPort.toLong();
    }

    private boolean isUniPort(Device d, Port p) {
        Port ulPort = getUplinkPort(d);
        if (ulPort != null) {
            return (ulPort.number().toLong() != p.number().toLong());
        }
        return false;
    }

    private SubscriberAndDeviceInformation getOltInfo(Device dev) {
        String devSerialNo = dev.serialNumber();
        return subsService.get(devSerialNo);
    }

    private MeterId getMeterIdFromBpMapping(DeviceId deviceId, String bandwidthProfile) {
        if (bpInfoToMeter.get(bandwidthProfile) == null) {
            log.warn("Bandwidth Profile '{}' is not currently mapped to a meter",
                      bandwidthProfile);
            return null;
        }

        Optional<MeterKey> meterKeyForDevice = bpInfoToMeter.get(bandwidthProfile)
                .stream()
                .filter(meterKey -> meterKey.deviceId().equals(deviceId))
                .findFirst();
        if (meterKeyForDevice.isPresent()) {
            log.debug("Found meter {} for bandwidth profile {}",
                      meterKeyForDevice.get().meterId(), bandwidthProfile);
            return meterKeyForDevice.get().meterId();
        } else {
            log.warn("Bandwidth profile '{}' is not currently mapped to a meter",
                     bandwidthProfile);
            return null;
        }
    }

    private void addMeterIdToBpMapping(DeviceId deviceId, MeterId meterId, String bandwidthProfile) {

        if (bpInfoToMeter.get(bandwidthProfile) == null) {
            bpInfoToMeter.put(bandwidthProfile,
                    new ArrayList<>(Arrays.asList(MeterKey.key(deviceId, meterId))));
        } else {
            List<MeterKey> meterKeyListForBp = bpInfoToMeter.get(bandwidthProfile);
            meterKeyListForBp.add(MeterKey.key(deviceId, meterId));
        }
    }

    /**
     * Removes meter key from programmed meters. If the meter has no reference
     * count in the data plane and is not present in the programmed-meters store
     * it will be removed.
     *
     * @param deviceId device identifier
     * @param bandwidthProfileId name of bandwidth profile
     */
    private void removeMeterIdFromPrgMeters(DeviceId deviceId,
                                             String bandwidthProfileId) {
        List<MeterKey> meterKeysForBp = bpInfoToMeter.get(bandwidthProfileId);
        if (meterKeysForBp != null) {
            meterKeysForBp.stream()
                    .filter(meterKey -> meterKey.deviceId().equals(deviceId))
                    .findFirst().ifPresent(mk -> {
                programmedMeters.remove(mk);
            });
        }
    }

    private class InternalDeviceListener implements DeviceListener {
        private Set<DeviceId> programmedDevices = Sets.newConcurrentHashSet();

        @Override
        public void event(DeviceEvent event) {
            eventExecutor.execute(() -> {
                DeviceId devId = event.subject().id();
                Device dev = event.subject();
                Port port = event.port();

                if (event.type() == DeviceEvent.Type.PORT_STATS_UPDATED) {
                    return;
                }

                if (getOltInfo(dev) == null) {
                    // it's possible that we got an event for a previously
                    // programmed OLT that is no longer available in SADIS
                    // we let such events go through
                    if (!programmedDevices.contains(devId)) {
                        log.warn("No device info found for {}, this is either "
                                + "not an OLT or not known to sadis", dev);
                        return;
                    }
                }

                log.debug("OLT got {} event for {}: {}", event.type(),
                          event.subject().id(), event);

                switch (event.type()) {
                    //TODO: Port handling and bookkeeping should be improved once
                    // olt firmware handles correct behaviour.
                    case PORT_ADDED:
                        if (isUniPort(dev, port)) {
                            post(new AccessDeviceEvent(AccessDeviceEvent.Type.UNI_ADDED, devId, port));
                            if (port.isEnabled()) {
                                processEapolFilteringObjectives(devId, port.number(), defaultBpId,
                                        null, VlanId.vlanId(EAPOL_DEFAULT_VLAN), true);
                            }
                        } else {
                            checkAndCreateDeviceFlows(dev);
                        }
                        break;
                    case PORT_REMOVED:
                        if (isUniPort(dev, port)) {
                            removeSubscriber(new ConnectPoint(devId, port.number()));
                            processEapolFilteringObjectives(devId, port.number(), defaultBpId,
                                    null, VlanId.vlanId(EAPOL_DEFAULT_VLAN), false);

                            post(new AccessDeviceEvent(AccessDeviceEvent.Type.UNI_REMOVED, devId, port));
                        }

                        break;
                    case PORT_UPDATED:
                        if (!isUniPort(dev, port)) {
                            break;
                        }

                        SubscriberAndDeviceInformation sub = programmedSubs
                                .get(new ConnectPoint(devId, port.number()));
                        VlanId vlanId = sub == null ? VlanId.vlanId(EAPOL_DEFAULT_VLAN) : sub.cTag();

                        String bpId = getCurrentBandwidthProfile(new ConnectPoint(devId, port.number()));

                        if (port.isEnabled()) {
                            processEapolFilteringObjectives(devId, port.number(), bpId,
                                    null, vlanId, true);

                            post(new AccessDeviceEvent(AccessDeviceEvent.Type.UNI_ADDED, devId, port));
                        } else {
                            processEapolFilteringObjectives(devId, port.number(), bpId,
                                    null, vlanId, false);
                            post(new AccessDeviceEvent(AccessDeviceEvent.Type.UNI_REMOVED, devId, port));
                        }
                        break;
                    case DEVICE_ADDED:
                        post(new AccessDeviceEvent(
                                AccessDeviceEvent.Type.DEVICE_CONNECTED, devId,
                                null, null));
                        programmedDevices.add(devId);
                        // Send UNI_ADDED events for all existing ports
                        deviceService.getPorts(devId).stream()
                                .filter(p -> isUniPort(dev, p))
                                .filter(Port::isEnabled)
                                .forEach(p -> post(new AccessDeviceEvent(
                                        AccessDeviceEvent.Type.UNI_ADDED, devId, p)));

                        checkAndCreateDeviceFlows(dev);
                        break;
                    case DEVICE_REMOVED:
                        deviceService.getPorts(devId).stream()
                                .filter(p -> isUniPort(dev, p))
                                .forEach(p -> post(new AccessDeviceEvent(
                                        AccessDeviceEvent.Type.UNI_REMOVED, devId, p)));
                        programmedDevices.remove(devId);
                        removeAllSubscribers(devId);
                        removeDeviceMetersFromBpMap(devId);
                        post(new AccessDeviceEvent(
                                AccessDeviceEvent.Type.DEVICE_DISCONNECTED, devId,
                                null, null));
                        break;
                    case DEVICE_AVAILABILITY_CHANGED:
                        if (deviceService.isAvailable(devId)) {
                            post(new AccessDeviceEvent(
                                    AccessDeviceEvent.Type.DEVICE_CONNECTED, devId,
                                    null, null));
                            programmedDevices.add(devId);
                            checkAndCreateDeviceFlows(dev);
                        } else {
                            programmedDevices.remove(devId);
                            removeAllSubscribers(devId);
                            removeDeviceMetersFromBpMap(devId);
                            post(new AccessDeviceEvent(
                                    AccessDeviceEvent.Type.DEVICE_DISCONNECTED, devId,
                                    null, null));
                        }
                        break;
                    case DEVICE_UPDATED:
                    case DEVICE_SUSPENDED:
                    case PORT_STATS_UPDATED:
                    default:
                        return;
                }
            });
        }

        private String getCurrentBandwidthProfile(ConnectPoint connectPoint) {
            SubscriberAndDeviceInformation sub = programmedSubs.get(connectPoint);
            if (sub != null) {
                return sub.upstreamBandwidthProfile();
            }
            return defaultBpId;
        }

        private void removeAllSubscribers(DeviceId deviceId) {
            List<ConnectPoint> connectPoints = programmedSubs.keySet().stream()
                    .filter(ks -> Objects.equals(ks.deviceId(), deviceId))
                    .collect(Collectors.toList());

            connectPoints.forEach(cp -> programmedSubs.remove(cp));
        }

        private void removeDeviceMetersFromBpMap(DeviceId deviceId) {
            bpInfoToMeter.values().forEach(meterKeys -> meterKeys.stream()
                    .filter(meterKey -> meterKey.deviceId().equals(deviceId)).findFirst().
                            ifPresent(mk -> {
                                meterKeys.remove(mk);
                                programmedMeters.remove(mk);
                                log.info("Deleted from the internal map. MeterKey {}", mk);
                                log.info("Programmed meters {}", programmedMeters);
                            }));
        }

    }

    private class InternalMeterListener implements MeterListener {

        @Override
        public void event(MeterEvent meterEvent) {
            if (deleteMeters && MeterEvent.Type.METER_REFERENCE_COUNT_ZERO.equals(meterEvent.type())) {
                log.debug("Zero Count Meter {} received", meterEvent.subject());
                Meter meter = meterEvent.subject();
                if (meter != null && appId.equals(meter.appId()) &&
                        !programmedMeters.contains(MeterKey.key(meter.deviceId(), meter.id()))) {
                    log.info("Deleting unreferenced, no longer programmed Meter {}",
                             meter.id());
                    deleteMeter(meter.deviceId(), meter.id());
                }
            } else if (MeterEvent.Type.METER_REMOVED.equals(meterEvent.type())) {
                log.debug("Meter removed event is received. Meter is {}",
                          meterEvent.subject());
                removeMeterFromBpMap(meterEvent.subject());
            }
        }

        private void deleteMeter(DeviceId deviceId, MeterId meterId) {
            Meter meter = meterService.getMeter(deviceId, meterId);
            if (meter != null) {
                MeterRequest meterRequest = DefaultMeterRequest.builder()
                        .withBands(meter.bands())
                        .withUnit(meter.unit())
                        .forDevice(deviceId)
                        .fromApp(appId)
                        .burst()
                        .remove();

                meterService.withdraw(meterRequest, meterId);
            }
        }

        private void removeMeterFromBpMap(Meter meter) {
            bpInfoToMeter.values().forEach(meterKeys -> meterKeys.stream()
                    .filter(meterKey -> (meterKey.deviceId().equals(meter.deviceId()))
                            && meterKey.meterId().equals(meter.id())).findFirst().
                            ifPresent(mk -> {
                                meterKeys.remove(mk);
                                programmedMeters.remove(mk);
                                log.info("Deleted from the internal map. MeterKey {}", mk);
                                log.info("Programmed meters {}", programmedMeters);
                            }));
        }
    }
}