/*
 * 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.interfaces;

import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import io.fd.honeycomb.v3po.translate.spi.write.ListWriterCustomizer;
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.TranslateUtils;
import io.fd.honeycomb.v3po.translate.write.WriteContext;
import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
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.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.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527._802dot1ad;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.SubInterfaces;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.sub.interfaces.SubInterface;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.interfaces._interface.sub.interfaces.SubInterfaceKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.match.attributes.MatchType;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.match.attributes.match.type.Default;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.vlan.rev150527.match.attributes.match.type.vlan.tagged.VlanTagged;
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.tags.Tag;
import org.opendaylight.yangtools.yang.binding.DataObject;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.openvpp.jvpp.VppBaseCallException;
import org.openvpp.jvpp.dto.CreateSubif;
import org.openvpp.jvpp.dto.CreateSubifReply;
import org.openvpp.jvpp.dto.SwInterfaceSetFlags;
import org.openvpp.jvpp.dto.SwInterfaceSetFlagsReply;
import org.openvpp.jvpp.future.FutureJVpp;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.CompletionStage;

import static com.google.common.base.Preconditions.checkState;
import static io.fd.honeycomb.v3po.translate.v3po.util.SubInterfaceUtils.getSubInterfaceName;
import static io.fd.honeycomb.v3po.translate.v3po.util.TranslateUtils.booleanToByte;

/**
 * Writer Customizer responsible for sub interface creation.<br> Sends {@code create_subif} message to VPP.<br>
 * Equivalent of invoking {@code vppclt create subif} command.
 */
public class SubInterfaceCustomizer extends FutureJVppCustomizer
        implements ListWriterCustomizer<SubInterface, SubInterfaceKey> {

    private static final Logger LOG = LoggerFactory.getLogger(SubInterfaceCustomizer.class);
    private final NamingContext interfaceContext;

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

    @Nonnull
    @Override
    public Optional<List<SubInterface>> extract(@Nonnull final InstanceIdentifier<SubInterface> currentId,
                                      @Nonnull final DataObject parentData) {
        return Optional.fromNullable(((SubInterfaces) parentData).getSubInterface());
    }


    @Override
    public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<SubInterface> id,
                                       @Nonnull final SubInterface dataAfter, @Nonnull final WriteContext writeContext)
            throws WriteFailedException.CreateFailedException {
        try {
            createSubInterface(id.firstKeyOf(Interface.class).getName(), dataAfter, writeContext);
        } catch (VppBaseCallException e) {
            LOG.warn("Failed to create sub interface for: {}, subInterface: {}", id.firstKeyOf(Interface.class).getName(), dataAfter);
            throw new WriteFailedException.CreateFailedException(id, dataAfter, e);
        }
    }

    private void createSubInterface(@Nonnull final String superIfName,
                                    @Nonnull final SubInterface subInterface,
                                    final WriteContext writeContext) throws VppBaseCallException {
        final int superIfIndex = interfaceContext.getIndex(superIfName, writeContext.getMappingContext());
        final CompletionStage<CreateSubifReply> createSubifReplyCompletionStage =
            getFutureJVpp().createSubif(getCreateSubifRequest(subInterface, superIfIndex));

        final CreateSubifReply reply =
            TranslateUtils.getReply(createSubifReplyCompletionStage.toCompletableFuture());

        setInterfaceState(reply.swIfIndex, booleanToByte(subInterface.isEnabled()));
        interfaceContext.addName(reply.swIfIndex,
            getSubInterfaceName(superIfName, Math.toIntExact(subInterface.getIdentifier())),
            writeContext.getMappingContext());
        LOG.debug("Sub interface created successfully for: {}, subInterface: {}", superIfName, subInterface);
    }

    private CreateSubif getCreateSubifRequest(@Nonnull final SubInterface subInterface, final int swIfIndex) {
        // TODO add validation
        CreateSubif request = new CreateSubif();
        request.subId = Math.toIntExact(subInterface.getIdentifier().intValue());
        request.swIfIndex = swIfIndex;

        final int numberOfTags = getNumberOfTags(subInterface);
        switch (numberOfTags) {
            case 0:
                request.noTags = 1;
                break;
            case 1:
                request.oneTag = 1;
                break;
            case 2:
                request.twoTags = 1;
                break;
        }
        request.dot1Ad = booleanToByte(_802dot1ad.class == subInterface.getVlanType());

        final MatchType matchType = subInterface.getMatch().getMatchType(); // todo match should be mandatory
        request.exactMatch =
                booleanToByte(matchType instanceof VlanTagged && ((VlanTagged) matchType).isMatchExactTags());
        request.defaultSub = booleanToByte(matchType instanceof Default);

        if (numberOfTags > 0) {
            for (final Tag tag : subInterface.getTags().getTag()) {
                if (tag.getIndex() == 0) {
                    setOuterTag(request, tag);
                } else if (tag.getIndex() == 1) {
                    setInnerTag(request, tag);
                }
            }
        }
        return request;
    }

    private void setOuterTag(final CreateSubif request, final Tag outerTag) {
        checkState(SVlan.class == outerTag.getDot1qTag().getTagType(), "Service Tag expected at index 0");
        final Dot1qTag.VlanId vlanId = outerTag.getDot1qTag().getVlanId();

        request.outerVlanId = dot1qVlanIdToChar(vlanId.getDot1qVlanId());
        request.outerVlanIdAny = booleanToByte(Dot1qTag.VlanId.Enumeration.Any.equals(vlanId.getEnumeration()));
    }

    private void setInnerTag(final CreateSubif request, final Tag innerTag) {
        checkState(CVlan.class == innerTag.getDot1qTag().getTagType(), "Customer Tag expected at index 1");
        final Dot1qTag.VlanId vlanId = innerTag.getDot1qTag().getVlanId();

        request.innerVlanId = dot1qVlanIdToChar(vlanId.getDot1qVlanId());
        request.innerVlanIdAny = booleanToByte(Dot1qTag.VlanId.Enumeration.Any.equals(vlanId.getEnumeration()));
    }

    private static int getNumberOfTags(@Nonnull final SubInterface subInterface) {
        final Tags tags = subInterface.getTags();
        if (tags == null) {
            return 0;
        }
        final List<Tag> tagList = tags.getTag();
        if (tagList == null) {
            return 0;
        }
        return tagList.size();
    }

    private static char dot1qVlanIdToChar(@Nullable Dot1qVlanId dot1qVlanId) {
        if (dot1qVlanId == null) {
            return 0; // tell VPP that optional argument is missing
        } else {
            return (char) dot1qVlanId.getValue().intValue();
        }
    }

    @Override
    public void updateCurrentAttributes(@Nonnull final InstanceIdentifier<SubInterface> id,
                                        @Nonnull final SubInterface dataBefore, @Nonnull final SubInterface dataAfter,
                                        @Nonnull final WriteContext writeContext)
            throws WriteFailedException.UpdateFailedException {
        if (Objects.equals(dataBefore.isEnabled(), dataAfter.isEnabled())) {
            LOG.debug("No state update will be performed. Ignoring config");
            return; // TODO shouldn't we throw exception here (if there will be dedicated L2 customizer)?
        }
        final String subIfaceName = getSubInterfaceName(id.firstKeyOf(Interface.class).getName(),
                Math.toIntExact(dataAfter.getIdentifier()));
        try {
            setInterfaceState(interfaceContext.getIndex(subIfaceName, writeContext.getMappingContext()),
                    booleanToByte(dataAfter.isEnabled()));
        } catch (VppBaseCallException e) {
            LOG.warn("Failed to update interface state for: interface if={}, enabled: {}",
                    subIfaceName, booleanToByte(dataAfter.isEnabled()));
            throw new WriteFailedException.UpdateFailedException(id, dataBefore, dataAfter, e);
        }
    }

    private void setInterfaceState(final int swIfIndex, final byte enabled) throws VppBaseCallException {
        final SwInterfaceSetFlags swInterfaceSetFlags = new SwInterfaceSetFlags();
        swInterfaceSetFlags.swIfIndex = swIfIndex;
        swInterfaceSetFlags.adminUpDown = enabled;

        final CompletionStage<SwInterfaceSetFlagsReply> swInterfaceSetFlagsReplyFuture =
                getFutureJVpp().swInterfaceSetFlags(swInterfaceSetFlags);

        LOG.debug("Updating interface state for: interface if={}, enabled: {}", swIfIndex, enabled);

        SwInterfaceSetFlagsReply reply = TranslateUtils.getReply(swInterfaceSetFlagsReplyFuture.toCompletableFuture());
        LOG.debug("Interface state updated successfully for: {}, index: {}, enabled: {}, ctxId: {}",
                swIfIndex, enabled, reply.context);
    }

    @Override
    public void deleteCurrentAttributes(@Nonnull final InstanceIdentifier<SubInterface> id,
                                        @Nonnull final SubInterface dataBefore,
                                        @Nonnull final WriteContext writeContext)
            throws WriteFailedException.DeleteFailedException {
        throw new UnsupportedOperationException("Sub interface delete is not supported");
    }
}