/*
 * Copyright (c) 2016 Cisco and/or its affiliates.
 *
 * 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 io.fd.honeycomb.v3po.translate.v3po.interfacesstate;

import static com.google.common.base.Preconditions.checkState;
import static io.fd.honeycomb.v3po.translate.v3po.interfacesstate.InterfaceCustomizer.DUMPED_IFCS_CONTEXT_KEY;
import static io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils.byteToBoolean;

import com.google.common.base.Preconditions;
import io.fd.honeycomb.v3po.translate.read.ReadContext;
import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
import io.fd.honeycomb.v3po.translate.spi.read.ListReaderCustomizer;
import io.fd.honeycomb.v3po.translate.v3po.util.FutureJVppCustomizer;
import io.fd.honeycomb.v3po.translate.v3po.util.NamingContext;
import io.fd.honeycomb.v3po.translate.v3po.util.SubInterfaceUtils;
import io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.stream.Collectors;
import javax.annotation.Nonnull;
import org.apache.commons.lang3.builder.ReflectionToStringBuilder;
import org.opendaylight.yang.gen.v1.urn.ieee.params.xml.ns.yang.dot1q.types.rev150626.CVlan;
import org.opendaylight.yang.gen.v1.urn.ieee.params.xml.ns.yang.dot1q.types.rev150626.Dot1qTagVlanType;
import org.opendaylight.yang.gen.v1.urn.ieee.params.xml.ns.yang.dot1q.types.rev150626.Dot1qVlanId;
import org.opendaylight.yang.gen.v1.urn.ieee.params.xml.ns.yang.dot1q.types.rev150626.SVlan;
import org.opendaylight.yang.gen.v1.urn.ieee.params.xml.ns.yang.dot1q.types.rev150626.dot1q.tag.or.any.Dot1qTag;
import org.opendaylight.yang.gen.v1.urn.ieee.params.xml.ns.yang.dot1q.types.rev150626.dot1q.tag.or.any.Dot1qTagBuilder;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.Interface;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.state.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.params.xml.ns.yang.vpp.vlan.rev150527.SubInterfaceStatus;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces.state._interface.SubInterfacesBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces.state._interface.sub.interfaces.SubInterface;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces.state._interface.sub.interfaces.SubInterfaceBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces.state._interface.sub.interfaces.SubInterfaceKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.match.attributes.match.type.DefaultBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.match.attributes.match.type.UntaggedBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.match.attributes.match.type.vlan.tagged.VlanTaggedBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.Match;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.MatchBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.Tags;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.TagsBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.tags.Tag;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.tags.TagBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.sub._interface.base.attributes.tags.TagKey;
import org.opendaylight.yangtools.concepts.Builder;
import org.opendaylight.yangtools.yang.binding.DataObject;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.openvpp.jvpp.VppBaseCallException;
import org.openvpp.jvpp.dto.SwInterfaceDetails;
import org.openvpp.jvpp.dto.SwInterfaceDetailsReplyDump;
import org.openvpp.jvpp.dto.SwInterfaceDump;
import org.openvpp.jvpp.future.FutureJVpp;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Customizer for reading sub interfaces form the VPP.
 */
public class SubInterfaceCustomizer extends FutureJVppCustomizer
        implements ListReaderCustomizer<SubInterface, SubInterfaceKey, SubInterfaceBuilder> {

    private static final Logger LOG = LoggerFactory.getLogger(SubInterfaceCustomizer.class);
    private NamingContext interfaceContext;
    private static final Dot1qTag.VlanId ANY_VLAN_ID = new Dot1qTag.VlanId(Dot1qTag.VlanId.Enumeration.Any);

    public SubInterfaceCustomizer(@Nonnull final FutureJVpp jvpp,
                                  @Nonnull final NamingContext interfaceContext) {
        super(jvpp);
        this.interfaceContext = Preconditions.checkNotNull(interfaceContext, "interfaceContext should not be null");
    }

    @Nonnull
    @Override
    public List<SubInterfaceKey> getAllIds(@Nonnull final InstanceIdentifier<SubInterface> id,
                                           @Nonnull final ReadContext context) throws ReadFailedException {
        try {
            // Relying here that parent InterfaceCustomizer was invoked first (PREORDER)
            // to fill in the context with initial ifc mapping
            final InterfaceKey key = id.firstKeyOf(Interface.class);
            final String ifaceName = key.getName();
            final int ifaceId = interfaceContext.getIndex(ifaceName, context.getMappingContext());

            // TODO if we know that full dump was already performed we could use cache
            // (checking if getCachedInterfaceDump() returns non empty map is not enough, because
            // we could be part of particular iface state read
            final SwInterfaceDump request = new SwInterfaceDump();
            request.nameFilter = "".getBytes();
            request.nameFilterValid = 0;

            final CompletableFuture<SwInterfaceDetailsReplyDump> swInterfaceDetailsReplyDumpCompletableFuture =
                    getFutureJVpp().swInterfaceDump(request).toCompletableFuture();
            final SwInterfaceDetailsReplyDump ifaces =
                    TranslateUtils.getReplyForRead(swInterfaceDetailsReplyDumpCompletableFuture, id);

            if (null == ifaces || null == ifaces.swInterfaceDetails) {
                LOG.warn("Looking for sub-interfaces, but no interfaces found in VPP");
                return Collections.emptyList();
            }

            // Cache interfaces dump in per-tx context to later be used in readCurrentAttributes
            context.getModificationCache().put(DUMPED_IFCS_CONTEXT_KEY, ifaces.swInterfaceDetails.stream()
                    .collect(Collectors.toMap(t -> t.swIfIndex, swInterfaceDetails -> swInterfaceDetails)));

            final List<SubInterfaceKey> interfacesKeys = ifaces.swInterfaceDetails.stream()
                    .filter(elt -> elt != null)
                    // accept only sub-interfaces for current iface:
                    .filter(elt -> elt.subId != 0 && elt.supSwIfIndex == ifaceId)
                    .map(details -> new SubInterfaceKey(new Long(details.subId)))
                    .collect(Collectors.toList());

            LOG.debug("Sub-interfaces of {} found in VPP: {}", ifaceName, interfacesKeys);
            return interfacesKeys;
        } catch (VppBaseCallException e) {
            throw new ReadFailedException(id,e);
        }
    }

    @Override
    public void merge(@Nonnull final Builder<? extends DataObject> builder,
                      @Nonnull final List<SubInterface> readData) {
        ((SubInterfacesBuilder) builder).setSubInterface(readData);
    }

    @Nonnull
    @Override
    public SubInterfaceBuilder getBuilder(@Nonnull final InstanceIdentifier<SubInterface> id) {
        return new SubInterfaceBuilder();
    }

    @Override
    public void readCurrentAttributes(@Nonnull final InstanceIdentifier<SubInterface> id,
                                      @Nonnull final SubInterfaceBuilder builder, @Nonnull final ReadContext ctx)
            throws ReadFailedException {
        final String subInterfaceName = getSubInterfaceName(id);
        LOG.debug("Reading attributes for sub interface: {}", subInterfaceName);

        final SwInterfaceDetails iface = InterfaceUtils.getVppInterfaceDetails(getFutureJVpp(), id, subInterfaceName,
                interfaceContext.getIndex(subInterfaceName, ctx.getMappingContext()), ctx.getModificationCache());
        LOG.debug("VPP sub-interface details: {}", ReflectionToStringBuilder.toString(iface));

        checkState(iface.subId != 0, "Interface returned by the VPP is not a sub-interface");

        builder.setIdentifier(Long.valueOf(iface.subId));
        builder.setKey(new SubInterfaceKey(builder.getIdentifier()));

        // sub-interface-base-attributes:
        builder.setTags(readTags(iface));
        builder.setMatch(readMatch(iface));

        // sub-interface-operational-attributes:
        builder.setAdminStatus(1 == iface.adminUpDown
                ? SubInterfaceStatus.Up
                : SubInterfaceStatus.Down);
        builder.setOperStatus(1 == iface.linkUpDown
                ? SubInterfaceStatus.Up
                : SubInterfaceStatus.Down);
        builder.setIfIndex(InterfaceUtils.vppIfIndexToYang(iface.swIfIndex));
        if (iface.l2AddressLength == 6) {
            builder.setPhysAddress(new PhysAddress(InterfaceUtils.vppPhysAddrToYang(iface.l2Address)));
        }
        if (0 != iface.linkSpeed) {
            builder.setSpeed(InterfaceUtils.vppInterfaceSpeedToYang(iface.linkSpeed));
        }
    }

    private static String getSubInterfaceName(final InstanceIdentifier<SubInterface> id) {
        return SubInterfaceUtils.getSubInterfaceName(id.firstKeyOf(Interface.class).getName(),
                Math.toIntExact(id.firstKeyOf(id.getTargetType()).getIdentifier()));
    }

    private Tags readTags(final SwInterfaceDetails iface) {
        final TagsBuilder tags = new TagsBuilder();
        final List<Tag> list = new ArrayList<>();
        if (iface.subNumberOfTags > 0) {
            if (iface.subOuterVlanIdAny == 1) {
                list.add(buildTag((short) 0, SVlan.class, ANY_VLAN_ID));
            } else {
                list.add(buildTag((short) 0, SVlan.class, buildVlanId(iface.subOuterVlanId)));
            }
            // inner tag (customer tag):
            if (iface.subNumberOfTags == 2) {
                if (iface.subInnerVlanIdAny == 1) {
                    list.add(buildTag((short) 1, CVlan.class, ANY_VLAN_ID));
                } else {
                    list.add(buildTag((short) 1, CVlan.class, buildVlanId(iface.subInnerVlanId)));
                }
            }
        }
        tags.setTag(list);
        return tags.build();
    }

    private static Tag buildTag(final short index, final Class<? extends Dot1qTagVlanType> tagType,
                                final Dot1qTag.VlanId vlanId) {
        TagBuilder tag = new TagBuilder();
        tag.setIndex(index);
        tag.setKey(new TagKey(index));
        final Dot1qTagBuilder dtag = new Dot1qTagBuilder();
        dtag.setTagType(tagType);
        dtag.setVlanId(vlanId);
        tag.setDot1qTag(dtag.build());
        return tag.build();
    }

    private static Dot1qTag.VlanId buildVlanId(final short vlanId) {
        return new Dot1qTag.VlanId(new Dot1qVlanId((int) vlanId));
    }

    private Match readMatch(final SwInterfaceDetails iface) {
        final MatchBuilder match = new MatchBuilder();
        if (iface.subDefault == 1) {
            match.setMatchType(new DefaultBuilder().build());
        } else if (iface.subNumberOfTags == 0) {
            match.setMatchType(new UntaggedBuilder().build());
        } else {
            final VlanTaggedBuilder tagged = new VlanTaggedBuilder();
            tagged.setMatchExactTags(byteToBoolean(iface.subExactMatch));
            match.setMatchType(
                    new org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.match.attributes.match.type.VlanTaggedBuilder()
                            .setVlanTagged(tagged.build()).build());
        }
        return match.build();
    }
}