/*
 * Copyright (c) 2016 Ericsson India Global Services Pvt Ltd. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.genius.interfacemanager;

import com.google.common.base.Optional;
import com.google.common.collect.ImmutableMap;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import com.google.common.util.concurrent.ListenableFuture;
import org.opendaylight.controller.md.sal.binding.api.DataBroker;
import org.opendaylight.controller.md.sal.binding.api.ReadOnlyTransaction;
import org.opendaylight.controller.md.sal.binding.api.WriteTransaction;
import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
import org.opendaylight.genius.datastoreutils.DataStoreJobCoordinator;
import org.opendaylight.genius.interfacemanager.commons.InterfaceManagerCommonUtils;
import org.opendaylight.genius.interfacemanager.globals.InterfaceInfo;
import org.opendaylight.genius.interfacemanager.globals.VlanInterfaceInfo;
import org.opendaylight.genius.interfacemanager.servicebindings.flowbased.utilities.FlowBasedServicesUtils;
import org.opendaylight.genius.mdsalutil.ActionType;
import org.opendaylight.genius.mdsalutil.ActionInfo;
import org.opendaylight.genius.mdsalutil.MDSALUtil;
import org.opendaylight.genius.mdsalutil.MetaDataUtil;
import org.opendaylight.genius.mdsalutil.NwConstants;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.iana._if.type.rev140508.L2vlan;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.iana._if.type.rev140508.Tunnel;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.Interfaces;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.InterfacesState;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.InterfaceKey;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.PhysAddress;
import org.opendaylight.yang.gen.v1.urn.opendaylight.action.types.rev131112.action.list.Action;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.FlowCapableNodeConnector;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.instruction.WriteMetadataCase;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.instruction.write.metadata._case.WriteMetadata;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.list.Instruction;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.AllocateIdInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.AllocateIdInputBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.AllocateIdOutput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.IdManagerService;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.IdPools;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.ReleaseIdInput;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.ReleaseIdInputBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.id.pools.IdPool;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.id.pools.IdPoolKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.IfL2vlan;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.IfL2vlan.L2vlanMode;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.IfTunnel;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.ParentRefs;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.TunnelTypeBase;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.TunnelTypeGre;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.TunnelTypeMplsOverGre;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.TunnelTypeVxlan;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.TunnelTypeVxlanGpe;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.servicebinding.rev160406.ServiceBindings;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.servicebinding.rev160406.ServiceModeBase;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.servicebinding.rev160406.service.bindings.ServicesInfo;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.servicebinding.rev160406.service.bindings.ServicesInfoKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.servicebinding.rev160406.service.bindings.services.info.BoundServices;
import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.servicebinding.rev160406.service.bindings.services.info.BoundServicesKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeConnectorId;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeId;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.Nodes;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.node.NodeConnector;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.node.NodeConnectorKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.Node;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.NodeKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.ovsdb.rev150105.DatapathId;
import org.opendaylight.yangtools.yang.binding.DataObject;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier.InstanceIdentifierBuilder;
import org.opendaylight.yangtools.yang.common.RpcResult;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static org.opendaylight.genius.interfacemanager.globals.InterfaceInfo.InterfaceType.VLAN_INTERFACE;

public class IfmUtil {
    private static final Logger LOG = LoggerFactory.getLogger(IfmUtil.class);
    private static final int INVALID_ID = 0;

    private static final ImmutableMap<Class<? extends TunnelTypeBase>, InterfaceInfo.InterfaceType> TUNNEL_TYPE_MAP =
            new ImmutableMap.Builder<Class<? extends TunnelTypeBase>, InterfaceInfo.InterfaceType>()
                    .put(TunnelTypeGre.class, InterfaceInfo.InterfaceType.GRE_TRUNK_INTERFACE)
                    .put(TunnelTypeMplsOverGre.class, InterfaceInfo.InterfaceType.MPLS_OVER_GRE)
                    .put(TunnelTypeVxlan.class, InterfaceInfo.InterfaceType.VXLAN_TRUNK_INTERFACE)
                    .put(TunnelTypeVxlanGpe.class, InterfaceInfo.InterfaceType.VXLAN_TRUNK_INTERFACE)
                    .build();

    public static BigInteger getDpnFromNodeConnectorId(NodeConnectorId portId) {
        /*
         * NodeConnectorId is of form 'openflow:dpnid:portnum'
         */
        String[] split = portId.getValue().split(IfmConstants.OF_URI_SEPARATOR);
        return new BigInteger(split[1]);
    }

    public static BigInteger getDpnFromInterface(org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface ifState){
        NodeConnectorId ncId = getNodeConnectorIdFromInterface(ifState);
        if(ncId != null){
            return getDpnFromNodeConnectorId(ncId);
        }
        return null;
    }
    public static String getPortNoFromInterfaceName(String ifaceName, DataBroker broker) {
        org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface ifState =
                InterfaceManagerCommonUtils.getInterfaceStateFromOperDS(ifaceName, broker);

        if(ifState == null){
            throw new NullPointerException("Interface information not present in oper DS for " +ifaceName);
        }
        String lowerLayerIf = ifState.getLowerLayerIf().get(0);
        NodeConnectorId nodeConnectorId = new NodeConnectorId(lowerLayerIf);
        String portNo = IfmUtil.getPortNoFromNodeConnectorId(nodeConnectorId);

        return portNo;
    }

    public static String getPortNoFromNodeConnectorId(NodeConnectorId portId) {
        /*
         * NodeConnectorId is of form 'openflow:dpnid:portnum'
         */
        String[] split = portId.getValue().split(IfmConstants.OF_URI_SEPARATOR);
        return split[2];
    }

    public static NodeId buildDpnNodeId(BigInteger dpnId) {
        return new NodeId(IfmConstants.OF_URI_PREFIX + dpnId);
    }

    public static InstanceIdentifier<Interface> buildId(String interfaceName) {
        //TODO Make this generic and move to AbstractDataChangeListener or Utils.
        InstanceIdentifierBuilder<Interface> idBuilder =
                InstanceIdentifier.builder(Interfaces.class).child(Interface.class, new InterfaceKey(interfaceName));
        InstanceIdentifier<Interface> id = idBuilder.build();
        return id;
    }

    public static InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface> buildStateInterfaceId(String interfaceName) {
        InstanceIdentifierBuilder<org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface> idBuilder =
                InstanceIdentifier.builder(InterfacesState.class)
                        .child(org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface.class,
                                new org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.InterfaceKey(interfaceName));
        InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface> id = idBuilder.build();
        return id;
    }

    public static org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.InterfaceKey getStateInterfaceKeyFromName(
            String name) {
        return new org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.InterfaceKey(name);
    }

    public static InstanceIdentifier<IdPool> getPoolId(String poolName){
        InstanceIdentifier.InstanceIdentifierBuilder<IdPool> idBuilder =
                InstanceIdentifier.builder(IdPools.class).child(IdPool.class, new IdPoolKey(poolName));
        InstanceIdentifier<IdPool> id = idBuilder.build();
        return id;
    }

    public static List<String> getPortNameAndSuffixFromInterfaceName(String intfName) {
        List<String> strList = new ArrayList<>(2);
        int index = intfName.indexOf(":");
        if (index != -1) {
            strList.add(0, intfName.substring(0, index));
            strList.add(1, intfName.substring(index));
        }
        return strList;
    }

    public static long getGroupId(long ifIndex, InterfaceInfo.InterfaceType infType) {
        if (infType == InterfaceInfo.InterfaceType.LOGICAL_GROUP_INTERFACE) {
            return ifIndex + IfmConstants.LOGICAL_GROUP_START;
        }
        else if (infType == VLAN_INTERFACE) {
            return ifIndex + IfmConstants.VLAN_GROUP_START;
        } else {
            return ifIndex + IfmConstants.TRUNK_GROUP_START;
        }
    }

    public static List<String> getDpIdPortNameAndSuffixFromInterfaceName(String intfName) {
        List<String> strList = new ArrayList<>(3);
        int index1 = intfName.indexOf(":");
        if (index1 != -1) {
            int index2 = intfName.indexOf(":", index1 + 1 );
            strList.add(0, intfName.substring(0, index1));
            if (index2 != -1) {
                strList.add(1, intfName.substring(index1, index2));
                strList.add(2, intfName.substring(index2));
            } else {
                strList.add(1, intfName.substring(index1));
                strList.add(2, "");
            }
        }
        return strList;
    }

    public static <T extends DataObject> Optional<T> read(LogicalDatastoreType datastoreType,
                                                          InstanceIdentifier<T> path, DataBroker broker) {
        try (ReadOnlyTransaction tx = broker.newReadOnlyTransaction()) {
            return tx.read(datastoreType, path).get();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static List<Action> getEgressActionsForInterface(String interfaceName, Long tunnelKey, Integer actionKey,
                                                            DataBroker dataBroker, Boolean isDefaultEgress) {
        List<ActionInfo> listActionInfo = getEgressActionInfosForInterface(interfaceName, tunnelKey, actionKey==null?0:actionKey, dataBroker, isDefaultEgress);
        List<Action> actionsList = new ArrayList<>();
        for (ActionInfo actionInfo : listActionInfo) {
            actionsList.add(actionInfo.buildAction());
        }
        return actionsList;
    }

    public static List<Instruction> getEgressInstructionsForInterface(String interfaceName, Long tunnelKey,
                                                                      DataBroker dataBroker, Boolean isDefaultEgress) {
        List<Instruction> instructions = new ArrayList<>();
        List<Action> actionList = MDSALUtil.buildActions(getEgressActionInfosForInterface(
                interfaceName, tunnelKey, 0, dataBroker, isDefaultEgress));
        instructions.add(MDSALUtil.buildApplyActionsInstruction(actionList));
        return  instructions;
    }

    public static List<Instruction> getEgressInstructionsForInterface(Interface interfaceInfo, String portNo,
                                                                      Long tunnelKey, boolean isDefaultEgress, int ifIndex) {
        List<Instruction> instructions = new ArrayList<>();
        InterfaceInfo.InterfaceType ifaceType = getInterfaceType(interfaceInfo);
        List<Action> actionList = MDSALUtil.buildActions(
                getEgressActionInfosForInterface(interfaceInfo, portNo, ifaceType, tunnelKey, 0, isDefaultEgress, ifIndex));
        instructions.add(MDSALUtil.buildApplyActionsInstruction(actionList));
        return  instructions;
    }


    public static List<ActionInfo> getEgressActionInfosForInterface(String     interfaceName,
                                                                    int        actionKeyStart,
                                                                    DataBroker dataBroker,
                                                                    Boolean isDefaultEgress) {
        return getEgressActionInfosForInterface(interfaceName, null, actionKeyStart, dataBroker, isDefaultEgress);
    }

    /**
     * Returns a list of Actions to be taken when sending a packet over an interface
     *
     * @param interfaceName
     * @param tunnelKey Optional.
     * @param actionKeyStart
     * @param dataBroker
     * @return
     */
    public static List<ActionInfo> getEgressActionInfosForInterface(String     interfaceName,
                                                                    Long       tunnelKey,
                                                                    int        actionKeyStart,
                                                                    DataBroker dataBroker,
                                                                    Boolean isDefaultEgress) {
        Interface interfaceInfo = InterfaceManagerCommonUtils.getInterfaceFromConfigDS(new InterfaceKey(interfaceName),
                dataBroker);
        if(interfaceInfo == null){
            throw new NullPointerException("Interface information not present in config DS for " +interfaceName);
        }
        org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface ifState =
                InterfaceManagerCommonUtils.getInterfaceStateFromOperDS(interfaceName, dataBroker);
        if(ifState == null){
            throw new NullPointerException("Interface information not present in oper DS for " +interfaceName);
        }
        String lowerLayerIf = ifState.getLowerLayerIf().get(0);
        NodeConnectorId nodeConnectorId = new NodeConnectorId(lowerLayerIf);
        String portNo = IfmUtil.getPortNoFromNodeConnectorId(nodeConnectorId);

        InterfaceInfo.InterfaceType ifaceType = getInterfaceType(interfaceInfo);
        return getEgressActionInfosForInterface(interfaceInfo, portNo, ifaceType, tunnelKey, actionKeyStart,
                isDefaultEgress, ifState.getIfIndex());
    }


    public static List<ActionInfo> getEgressActionInfosForInterface(Interface interfaceInfo,
                                                                    String portNo,
                                                                    InterfaceInfo.InterfaceType ifaceType,
                                                                    Long       tunnelKey,
                                                                    int        actionKeyStart,
                                                                    boolean isDefaultEgress,
                                                                    int ifIndex) {
        List<ActionInfo> result = new ArrayList<>();
        switch (ifaceType) {
            case VLAN_INTERFACE:
                if(isDefaultEgress) {
                    IfL2vlan vlanIface = interfaceInfo.getAugmentation(IfL2vlan.class);
                    LOG.trace("L2Vlan: {}", vlanIface);
                    boolean isVlanTransparent = false;
                    long vlanVid = 0;
                    if (vlanIface != null) {
                        vlanVid = vlanIface.getVlanId() == null ? 0 : vlanIface.getVlanId().getValue();
                        isVlanTransparent = vlanIface.getL2vlanMode() == IfL2vlan.L2vlanMode.Transparent;
                    }
                    if (vlanVid != 0 && !isVlanTransparent) {
                        result.add(new ActionInfo(ActionType.push_vlan, new String[]{}, actionKeyStart++));
                        result.add(new ActionInfo(ActionType.set_field_vlan_vid,
                                new String[]{Long.toString(vlanVid)}, actionKeyStart++));
                    }
                    result.add(new ActionInfo(ActionType.output, new String[]{portNo}, actionKeyStart++));
                }else{
                    long regValue = MetaDataUtil.getReg6ValueForLPortDispatcher(ifIndex, NwConstants.DEFAULT_SERVICE_INDEX);
                    result.add(new ActionInfo(ActionType.nx_load_reg_6,
                            new String[]{Integer.toString(IfmConstants.REG6_START_INDEX), Integer.toString(IfmConstants.REG6_END_INDEX),
                                    Long.toString(regValue)}, actionKeyStart++));
                    result.add(new ActionInfo(ActionType.nx_resubmit,
                            new String[]{Short.toString(NwConstants.EGRESS_LPORT_DISPATCHER_TABLE)}, actionKeyStart++));
                }
                break;
            case MPLS_OVER_GRE:
            case VXLAN_TRUNK_INTERFACE:
            case GRE_TRUNK_INTERFACE:
                //TODO tunnel_id to encode GRE key, once it is supported
                // Until then, tunnel_id should be "cleaned", otherwise it stores the value coming from a VXLAN tunnel
                if (tunnelKey == null)
                    tunnelKey = 0L;
                result.add(new ActionInfo(ActionType.set_field_tunnel_id,
                    new BigInteger[]{BigInteger.valueOf(tunnelKey)},actionKeyStart++));
                result.add(new ActionInfo(ActionType.output, new String[]{portNo}, actionKeyStart++));
                break;

            default:
                LOG.warn("Interface Type {} not handled yet", ifaceType);
                break;
        }
        return result;
    }

    public static NodeId getNodeIdFromNodeConnectorId(NodeConnectorId ncId) {
        return new NodeId(ncId.getValue().substring(0,ncId.getValue().lastIndexOf(":")));
    }

    public static BigInteger[] mergeOpenflowMetadataWriteInstructions(List<Instruction> instructions) {
        BigInteger metadata = new BigInteger("0", 16);
        BigInteger metadataMask = new BigInteger("0", 16);
        if (instructions != null && !instructions.isEmpty()) {
            // check if metadata write instruction is present
            for (Instruction instruction : instructions) {
                org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.Instruction actualInstruction = instruction.getInstruction();
                if (actualInstruction instanceof WriteMetadataCase) {
                    WriteMetadataCase writeMetaDataInstruction = (WriteMetadataCase) actualInstruction ;
                    WriteMetadata availableMetaData = writeMetaDataInstruction.getWriteMetadata();
                    metadata = metadata.or(availableMetaData.getMetadata());
                    metadataMask = metadataMask.or(availableMetaData.getMetadataMask());
                }
            }
        }
        return new BigInteger[] { metadata, metadataMask };
    }

    public static Integer allocateId(IdManagerService idManager, String poolName, String idKey) {
        AllocateIdInput getIdInput = new AllocateIdInputBuilder()
                .setPoolName(poolName)
                .setIdKey(idKey).build();
        try {
            Future<RpcResult<AllocateIdOutput>> result = idManager.allocateId(getIdInput);
            RpcResult<AllocateIdOutput> rpcResult = result.get();
            if(rpcResult.isSuccessful()) {
                return rpcResult.getResult().getIdValue().intValue();
            } else {
                LOG.warn("RPC Call to Get Unique Id returned with Errors {}", rpcResult.getErrors());
            }
        } catch (InterruptedException | ExecutionException e) {
            LOG.warn("Exception when getting Unique Id",e);
        }
        return INVALID_ID;
    }

    public static void releaseId(IdManagerService idManager, String poolName, String idKey) {
        ReleaseIdInput idInput = new ReleaseIdInputBuilder()
                .setPoolName(poolName)
                .setIdKey(idKey).build();
        try {
            Future<RpcResult<Void>> result = idManager.releaseId(idInput);
            RpcResult<Void> rpcResult = result.get();
            if(!rpcResult.isSuccessful()) {
                LOG.warn("RPC Call to release Id {} with Key {} returned with Errors {}",
                        idKey, rpcResult.getErrors());
            }
        } catch (InterruptedException | ExecutionException e) {
            LOG.warn("Exception when releasing Id for key {}", idKey, e);
        }
    }

    public static BigInteger getDpnId(DatapathId datapathId){
        if (datapathId != null) {
            // Adding logs for a random issue spotted during datapath id conversion
            String dpIdStr = datapathId.getValue().replace(":", "");
            BigInteger dpnId =  new BigInteger(dpIdStr, 16);
            return dpnId;
        }
        return null;
    }

    public static NodeConnectorId getNodeConnectorIdFromInterface(String interfaceName, DataBroker dataBroker) {
        return FlowBasedServicesUtils.getNodeConnectorIdFromInterface(interfaceName, dataBroker);
    }

    public static String getPortName(DataBroker dataBroker, NodeConnectorId ncId){
        InstanceIdentifier<NodeConnector> ncIdentifier =
                InstanceIdentifier.builder(Nodes.class)
                        .child(Node.class, new NodeKey(getNodeIdFromNodeConnectorId(ncId)))
                        .child(NodeConnector.class, new NodeConnectorKey(ncId)).build();
        return read(LogicalDatastoreType.OPERATIONAL, ncIdentifier, dataBroker).transform(
                nc -> nc.getAugmentation(FlowCapableNodeConnector.class).getName()).orNull();
    }

    public static NodeConnectorId getNodeConnectorIdFromInterface(org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface ifState){
        if(ifState != null) {
            List<String> ofportIds = ifState.getLowerLayerIf();
            return new NodeConnectorId(ofportIds.get(0));
        }
        return null;
    }

    public static InterfaceInfo.InterfaceType getInterfaceType(Interface iface) {
        InterfaceInfo.InterfaceType interfaceType = org.opendaylight.genius.interfacemanager.globals.InterfaceInfo.InterfaceType.UNKNOWN_INTERFACE;
        Class<? extends org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.InterfaceType> ifType = iface
                .getType();

        if (ifType.isAssignableFrom(L2vlan.class)) {
            interfaceType = VLAN_INTERFACE;
        } else if (ifType.isAssignableFrom(Tunnel.class)) {
            IfTunnel ifTunnel = iface.getAugmentation(IfTunnel.class);
            Class<? extends org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.TunnelTypeBase> tunnelType = ifTunnel
                    .getTunnelInterfaceType();
            interfaceType = TUNNEL_TYPE_MAP.get(tunnelType);
        }
        return interfaceType;
    }

    public static VlanInterfaceInfo getVlanInterfaceInfo(String interfaceName, Interface iface, BigInteger dpId) {

        short vlanId = 0;
        String portName = null;
        IfL2vlan vlanIface = iface.getAugmentation(IfL2vlan.class);
        ParentRefs parentRefs = iface.getAugmentation(ParentRefs.class);
        if (parentRefs != null && parentRefs.getParentInterface() != null) {
            portName = parentRefs.getParentInterface();
        }else {
            LOG.warn("Portname set to null since parentRef is Null");
        }
        VlanInterfaceInfo vlanInterfaceInfo = new VlanInterfaceInfo(dpId, portName, vlanId);

        if (vlanIface != null) {
            vlanId = vlanIface.getVlanId() == null ? 0 : vlanIface.getVlanId().getValue().shortValue();
            L2vlanMode l2VlanMode = vlanIface.getL2vlanMode();

            if (l2VlanMode == L2vlanMode.Transparent) {
                vlanInterfaceInfo.setVlanTransparent(true);
            }
            if (l2VlanMode == L2vlanMode.NativeUntagged) {
                vlanInterfaceInfo.setUntaggedVlan(true);
            }
            vlanInterfaceInfo.setVlanId(vlanId);

        }
        return vlanInterfaceInfo;
    }

    public static BigInteger getDeadBeefBytesForMac() {
        return new BigInteger("FFFFFFFF", 16).and(new BigInteger(IfmConstants.DEAD_BEEF_MAC_PREFIX, 16)).shiftLeft(16);
    }

    public static BigInteger fillPortNumberToMac(long portNumber) {
        return new BigInteger("FFFF", 16).and(BigInteger.valueOf(portNumber));
    }

    public static String generateMacAddress(long portNo){
        String unformattedMAC = getDeadBeefBytesForMac().or(fillPortNumberToMac(portNo)).toString(16);
        return unformattedMAC.replaceAll("(.{2})", "$1"+IfmConstants.MAC_SEPARATOR).
                substring(0, IfmConstants.MAC_STRING_LENGTH);
    }

    public static PhysAddress getPhyAddress(long portNo, FlowCapableNodeConnector flowCapableNodeConnector){
        String southboundMacAddress = flowCapableNodeConnector.getHardwareAddress().getValue();
        if(IfmConstants.INVALID_MAC.equals(southboundMacAddress)){
            LOG.debug("Invalid MAC Address received for {}, generating MAC Address", flowCapableNodeConnector.getName());
            southboundMacAddress = generateMacAddress(portNo);
        }
        return new PhysAddress(southboundMacAddress);
    }

    public static void bindService(WriteTransaction t, String interfaceName, BoundServices serviceInfo,
                                   Class<? extends ServiceModeBase> serviceMode){
        LOG.info("Binding Service {} for : {}", serviceInfo.getServiceName(), interfaceName);
        InstanceIdentifier<BoundServices> boundServicesInstanceIdentifier = InstanceIdentifier.builder(ServiceBindings.class)
                .child(ServicesInfo.class, new ServicesInfoKey(interfaceName, serviceMode))
                .child(BoundServices.class, new BoundServicesKey(serviceInfo.getServicePriority())).build();
        t.put(LogicalDatastoreType.CONFIGURATION, boundServicesInstanceIdentifier, serviceInfo, true);
    }

    public static void unbindService(DataBroker dataBroker, String interfaceName, InstanceIdentifier<BoundServices>
            boundServicesInstanceIdentifier, String parentInterface){
        LOG.info("Unbinding Service from : {}", interfaceName);
        DataStoreJobCoordinator dataStoreJobCoordinator = DataStoreJobCoordinator.getInstance();
        dataStoreJobCoordinator.enqueueJob(parentInterface,
                () -> {
                    WriteTransaction t = dataBroker.newWriteOnlyTransaction();
                    t.delete(LogicalDatastoreType.CONFIGURATION, boundServicesInstanceIdentifier);
                    List<ListenableFuture<Void>> futures = new ArrayList<>();
                    futures.add(t.submit());
                    return futures;
                }
        );
    }
}