/*
 * Copyright (c) 2016 Cisco Systems, Inc. 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.protocol.bgp.rib.impl.config;

import static org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IetfInetUtil.INSTANCE;

import com.google.common.collect.ImmutableList;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import org.opendaylight.protocol.bgp.mode.api.PathSelectionMode;
import org.opendaylight.protocol.bgp.mode.impl.add.all.paths.AllPathSelection;
import org.opendaylight.protocol.bgp.mode.impl.add.n.paths.AddPathBestNPathSelection;
import org.opendaylight.protocol.bgp.openconfig.spi.BGPTableTypeRegistryConsumer;
import org.opendaylight.protocol.bgp.rib.spi.BGPPeerTracker;
import org.opendaylight.protocol.concepts.KeyMapping;
import org.opendaylight.protocol.util.Ipv4Util;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.multiprotocol.rev151009.BgpCommonAfiSafiList;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.multiprotocol.rev151009.bgp.common.afi.safi.list.AfiSafi;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.multiprotocol.rev151009.bgp.common.afi.safi.list.AfiSafiBuilder;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.BgpNeighborAddPathsConfig;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.BgpNeighborGroup;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.BgpNeighborTransportConfig;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.neighbor.group.RouteReflector;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.neighbor.group.Timers;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.neighbor.group.Transport;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.neighbor.group.transport.Config;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.neighbors.Neighbor;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.neighbors.NeighborKey;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.peer.group.PeerGroup;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.top.Bgp;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.top.bgp.Neighbors;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.types.rev151009.IPV4UNICAST;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.types.rev151009.PeerType;
import org.opendaylight.yang.gen.v1.http.openconfig.net.yang.network.instance.rev151018.network.instance.top.network.instances.network.instance.protocols.Protocol;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.AsNumber;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.PortNumber;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.BgpTableType;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.SendReceive;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.add.path.capability.AddressFamilies;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.add.path.capability.AddressFamiliesBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.openconfig.extensions.rev180329.GlobalAddPathsConfig;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.openconfig.extensions.rev180329.GlobalConfigAugmentation;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.openconfig.extensions.rev180329.NeighborAddPathsConfig;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.openconfig.extensions.rev180329.NeighborPeerGroupConfig;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.openconfig.extensions.rev180329.NeighborTransportConfig;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.openconfig.extensions.rev180329.PeerGroupTransportConfig;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev180329.PeerRole;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev180329.rib.TablesKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev180329.ClusterIdentifier;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;

public final class OpenConfigMappingUtil {

    static final String APPLICATION_PEER_GROUP_NAME = "application-peers";
    static final int HOLDTIMER = 90;
    private static final AfiSafi IPV4_AFISAFI = new AfiSafiBuilder().setAfiSafiName(IPV4UNICAST.class).build();
    private static final List<AfiSafi> DEFAULT_AFISAFI = ImmutableList.of(IPV4_AFISAFI);
    private static final int CONNECT_RETRY = 30;
    private static final PortNumber PORT = new PortNumber(179);

    private OpenConfigMappingUtil() {
        throw new UnsupportedOperationException();
    }

    public static String getRibInstanceName(final InstanceIdentifier<?> rootIdentifier) {
        return rootIdentifier.firstKeyOf(Protocol.class).getName();
    }

    @Nullable
    private static Integer getHoldTimer(final Timers timers) {
        if (timers == null) {
            return null;
        }
        final org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.neighbor.group.timers
                .Config config = timers.getConfig();
        if (config != null && config.getHoldTime() != null) {
            return config.getHoldTime().intValue();
        }
        return null;
    }

    @Nullable
    private static AsNumber getRemotePeerAs(final org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp
            .rev151009.bgp.neighbor.group.Config config) {
        if (config != null) {
            final AsNumber peerAs = config.getPeerAs();
            if (peerAs != null) {
                return peerAs;
            }
        }
        return null;
    }

    @Nullable
    private static Boolean isActive(final Transport transport) {
        if (transport != null) {
            final Config config = transport.getConfig();
            if (config != null && config.isPassiveMode() != null) {
                return !config.isPassiveMode();
            }
        }
        return null;
    }

    @Nullable
    private static Integer getRetryTimer(final Timers timers) {
        if (timers == null) {
            return null;
        }
        final org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.neighbor.group.timers
                .Config config = timers.getConfig();
        if (config != null && config.getConnectRetry() != null) {
            return config.getConnectRetry().intValue();
        }
        return null;
    }

    public static KeyMapping getNeighborKey(final Neighbor neighbor) {
        if (neighbor.getConfig() != null) {
            final String authPassword = neighbor.getConfig().getAuthPassword();
            if (authPassword != null) {
                return KeyMapping.getKeyMapping(INSTANCE.inetAddressFor(neighbor.getNeighborAddress()), authPassword);
            }
        }
        return null;
    }

    public static InstanceIdentifier<Neighbor> getNeighborInstanceIdentifier(
            final InstanceIdentifier<Bgp> rootIdentifier,
            final NeighborKey neighborKey) {
        return rootIdentifier.child(Neighbors.class).child(Neighbor.class, neighborKey);
    }

    public static String getNeighborInstanceName(final InstanceIdentifier<?> rootIdentifier) {
        return Ipv4Util.toStringIP(rootIdentifier.firstKeyOf(Neighbor.class).getNeighborAddress());
    }

    @Nullable
    private static PortNumber getPort(@Nullable final Transport transport) {
        if (transport != null) {
            final Config config = transport.getConfig();
            if (config != null) {
                final NeighborTransportConfig peerTc = config.getAugmentation(NeighborTransportConfig.class);
                if (peerTc != null) {
                    return peerTc.getRemotePort();
                }
                final PeerGroupTransportConfig peerGroupTc = config.getAugmentation(PeerGroupTransportConfig.class);
                if (peerGroupTc != null) {
                    return peerGroupTc.getRemotePort();
                }
            }
        }
        return null;
    }

    //make sure IPv4 Unicast (RFC 4271) when required
    public static List<AfiSafi> getAfiSafiWithDefault(
            final BgpCommonAfiSafiList afiSAfis, final boolean setDeafultIPv4) {
        if (afiSAfis == null || afiSAfis.getAfiSafi() == null) {
            return setDeafultIPv4 ? DEFAULT_AFISAFI : Collections.emptyList();
        }
        final List<AfiSafi> afiSafi = afiSAfis.getAfiSafi();
        if (setDeafultIPv4) {
            final boolean anyMatch = afiSafi.stream()
                    .anyMatch(input -> input.getAfiSafiName().equals(IPV4UNICAST.class));
            if (!anyMatch) {
                afiSafi.add(IPV4_AFISAFI);
            }
        }
        return afiSafi;
    }

    public static ClusterIdentifier getGlobalClusterIdentifier(final org.opendaylight.yang.gen.v1.http.openconfig.net
            .yang.bgp.rev151009.bgp.global.base.Config globalConfig) {
        final GlobalConfigAugmentation globalConfigAugmentation
                = globalConfig.getAugmentation(GlobalConfigAugmentation.class);
        if (globalConfigAugmentation != null && globalConfigAugmentation.getRouteReflectorClusterId() != null) {
            return new ClusterIdentifier(globalConfigAugmentation.getRouteReflectorClusterId().getIpv4Address());
        }
        return new ClusterIdentifier(globalConfig.getRouterId());
    }

    @Nullable
    public static ClusterIdentifier getNeighborClusterIdentifier(
            @Nullable final RouteReflector routeReflector,
            @Nullable final PeerGroup peerGroup) {
        if (peerGroup != null) {
            final ClusterIdentifier clusteriId = extractClusterId(peerGroup.getRouteReflector());
            if (clusteriId != null) {
                return clusteriId;
            }
        }

        return extractClusterId(routeReflector);
    }

    private static ClusterIdentifier extractClusterId(final RouteReflector routeReflector) {
        if (routeReflector != null) {
            final org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.neighbor.group.route
                    .reflector.Config config = routeReflector.getConfig();
            if (config != null && config.getRouteReflectorClusterId() != null) {
                return new ClusterIdentifier(config.getRouteReflectorClusterId().getIpv4Address());
            }
        }
        return null;
    }

    public static Map<BgpTableType, PathSelectionMode> toPathSelectionMode(final List<AfiSafi> afiSafis,
            final BGPTableTypeRegistryConsumer tableTypeRegistry, final BGPPeerTracker peerTracker) {
        final Map<BgpTableType, PathSelectionMode> pathSelectionModes = new HashMap<>();
        for (final AfiSafi afiSafi : afiSafis) {
            final BgpNeighborAddPathsConfig afiSafi2 = afiSafi.getAugmentation(GlobalAddPathsConfig.class);
            if (afiSafi2 != null) {
                final Optional<BgpTableType> bgpTableType = tableTypeRegistry.getTableType(afiSafi.getAfiSafiName());
                if (bgpTableType.isPresent()) {
                    final Short sendMax = afiSafi2.getSendMax();
                    final PathSelectionMode selectionMode;
                    if (sendMax > 1) {
                        selectionMode = new AddPathBestNPathSelection(sendMax.longValue(), peerTracker);
                    } else {
                        selectionMode = new AllPathSelection(peerTracker);
                    }
                    pathSelectionModes.put(bgpTableType.get(), selectionMode);
                }
            }
        }
        return pathSelectionModes;
    }

    public static boolean isApplicationPeer(final Neighbor neighbor) {
        final org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009.bgp.neighbor.group
                .Config config = neighbor.getConfig();
        if (config != null) {
            final NeighborPeerGroupConfig config1 = config.getAugmentation(NeighborPeerGroupConfig.class);
            if (config1 != null) {
                final String peerGroup = config1.getPeerGroup();
                return peerGroup != null && peerGroup.equals(APPLICATION_PEER_GROUP_NAME);
            }
        }
        return false;
    }

    public static List<AddressFamilies> toAddPathCapability(final List<AfiSafi> afiSafis,
            final BGPTableTypeRegistryConsumer tableTypeRegistry) {
        final List<AddressFamilies> addPathCapability = new ArrayList<>();
        for (final AfiSafi afiSafi : afiSafis) {
            final BgpNeighborAddPathsConfig afiSafi1 = afiSafi.getAugmentation(NeighborAddPathsConfig.class);
            final Optional<BgpTableType> bgpTableType = tableTypeRegistry.getTableType(afiSafi.getAfiSafiName());
            if (afiSafi1 != null && bgpTableType.isPresent()) {
                final AddressFamiliesBuilder builder = new AddressFamiliesBuilder(bgpTableType.get());
                builder.setSendReceive(toSendReceiveMode(afiSafi1));
                addPathCapability.add(builder.build());
            }
        }
        return addPathCapability;
    }

    private static SendReceive toSendReceiveMode(final BgpNeighborAddPathsConfig addPath) {
        if (addPath.isReceive() && addPath.getSendMax() != null) {
            return SendReceive.Both;
        }
        if (addPath.getSendMax() != null) {
            return SendReceive.Send;
        }
        return SendReceive.Receive;
    }

    public static PeerRole toPeerRole(final BgpNeighborGroup neighbor) {
        if (isRrClient(neighbor)) {
            return PeerRole.RrClient;
        }

        if (neighbor.getConfig() != null) {
            final PeerType peerType = neighbor.getConfig().getPeerType();
            if (peerType == PeerType.EXTERNAL) {
                return PeerRole.Ebgp;
            } else if (peerType == PeerType.INTERNAL) {
                return PeerRole.Ibgp;
            }
        }
        return null;
    }

    private static boolean isRrClient(final BgpNeighborGroup neighbor) {
        final RouteReflector routeReflector = neighbor.getRouteReflector();
        if (routeReflector != null && routeReflector.getConfig() != null) {
            return routeReflector.getConfig().isRouteReflectorClient();
        }
        return false;
    }

    public static List<BgpTableType> toTableTypes(final List<AfiSafi> afiSafis,
            final BGPTableTypeRegistryConsumer tableTypeRegistry) {
        return afiSafis.stream()
                .map(afiSafi -> tableTypeRegistry.getTableType(afiSafi.getAfiSafiName()))
                .filter(Optional::isPresent)
                .map(Optional::get)
                .collect(Collectors.toList());
    }

    public static Set<TablesKey> toTableKey(final List<AfiSafi> afiSafis, final BGPTableTypeRegistryConsumer
            tableTypeRegistry) {
        return afiSafis.stream()
                .map(afiSafi -> tableTypeRegistry.getTableKey(afiSafi.getAfiSafiName()))
                .filter(Optional::isPresent)
                .map(Optional::get)
                .collect(Collectors.toSet());
    }

    @Nonnull
    public static boolean isActive(final Neighbor neighbor, final PeerGroup peerGroup) {
        Boolean activeConnection = null;
        if (peerGroup != null) {
            activeConnection = isActive(peerGroup.getTransport());
        }

        if (activeConnection == null) {
            activeConnection = isActive(neighbor.getTransport());
        }
        if (activeConnection == null) {
            return true;
        }
        return activeConnection;
    }

    @Nonnull
    public static PeerRole toPeerRole(final Neighbor neighbor, final PeerGroup peerGroup) {
        PeerRole role = null;
        if (peerGroup != null) {
            role = toPeerRole(peerGroup);
        }

        if (role == null) {
            role = toPeerRole(neighbor);
        }

        if (role == null) {
            return PeerRole.Ibgp;
        }
        return role;
    }

    public static int getHoldTimer(final Neighbor neighbor, final PeerGroup peerGroup) {
        Integer hold = null;
        if (peerGroup != null) {
            hold = getHoldTimer(peerGroup.getTimers());
        }

        if (hold == null) {
            hold = getHoldTimer(neighbor.getTimers());
        }

        if (hold == null) {
            return HOLDTIMER;
        }

        return hold;
    }

    @Nonnull
    public static AsNumber getRemotePeerAs(final org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp.rev151009
            .bgp.neighbor.group.Config config, final PeerGroup peerGroup, final AsNumber localAs) {
        AsNumber neighborAs = null;
        if (peerGroup != null) {
            neighborAs = getRemotePeerAs(peerGroup.getConfig());
        }

        if (neighborAs == null) {
            neighborAs = getRemotePeerAs(config);
        }

        if (neighborAs == null) {
            return localAs;
        }
        return neighborAs;
    }

    @Nonnull
    public static AsNumber getLocalPeerAs(@Nullable final org.opendaylight.yang.gen.v1.http.openconfig.net.yang.bgp
            .rev151009.bgp.neighbor.group.Config config, @Nonnull final AsNumber globalAs) {
        if (config != null) {
            final AsNumber peerAs = config.getLocalAs();
            if (peerAs != null) {
                return peerAs;
            }
        }
        return globalAs;
    }

    public static int getRetryTimer(final Neighbor neighbor, final PeerGroup peerGroup) {
        Integer retryTimer = null;
        if (peerGroup != null) {
            retryTimer = getRetryTimer(peerGroup.getTimers());
        }

        if (retryTimer == null) {
            retryTimer = getRetryTimer(neighbor.getTimers());
        }

        if (retryTimer == null) {
            return CONNECT_RETRY;
        }

        return retryTimer;
    }

    @Nonnull
    public static PortNumber getPort(final Neighbor neighbor, final PeerGroup peerGroup) {
        PortNumber port = null;
        if (peerGroup != null) {
            port = getPort(peerGroup.getTransport());
        }

        if (port == null) {
            port = getPort(neighbor.getTransport());
        }

        if (port == null) {
            return PORT;
        }

        return port;
    }

    @Nullable
    public static IpAddress getLocalAddress(@Nullable final Transport transport) {
        if (transport != null && transport.getConfig() != null) {
            final BgpNeighborTransportConfig.LocalAddress localAddress = transport.getConfig().getLocalAddress();
            if (localAddress != null ) {
                return localAddress.getIpAddress();
            }
        }
        return null;
    }
}