/*
 * 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 io.fd.honeycomb.v3po.translate.v3po.interfacesstate.InterfaceUtils.isInterfaceOfType;

import io.fd.honeycomb.v3po.translate.read.ReadContext;
import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
import io.fd.honeycomb.v3po.translate.spi.read.ChildReaderCustomizer;
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 java.math.BigInteger;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CompletionStage;
import java.util.stream.Collectors;
import javax.annotation.Nonnull;
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.opendaylight.params.xml.ns.yang.v3po.rev150105.VhostUserRole;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VppInterfaceStateAugmentationBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.interfaces.state._interface.VhostUser;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.interfaces.state._interface.VhostUserBuilder;
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.SwInterfaceVhostUserDetails;
import org.openvpp.jvpp.dto.SwInterfaceVhostUserDetailsReplyDump;
import org.openvpp.jvpp.dto.SwInterfaceVhostUserDump;
import org.openvpp.jvpp.future.FutureJVpp;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


public class VhostUserCustomizer extends FutureJVppCustomizer
        implements ChildReaderCustomizer<VhostUser, VhostUserBuilder> {

    private static final Logger LOG = LoggerFactory.getLogger(VhostUserCustomizer.class);
    public static final String DUMPED_VHOST_USERS_CONTEXT_KEY = VhostUserCustomizer.class.getName() + "dumpedVhostUsersDuringGetAllIds";
    private NamingContext interfaceContext;

    public VhostUserCustomizer(@Nonnull final FutureJVpp jvpp, @Nonnull final NamingContext interfaceContext) {
        super(jvpp);
        this.interfaceContext = interfaceContext;
    }

    @Override
    public void merge(@Nonnull Builder<? extends DataObject> parentBuilder, @Nonnull VhostUser readValue) {
        ((VppInterfaceStateAugmentationBuilder) parentBuilder).setVhostUser(readValue);
    }

    @Nonnull
    @Override
    public VhostUserBuilder getBuilder(@Nonnull InstanceIdentifier<VhostUser> id) {
        return new VhostUserBuilder();
    }

    @Override
    public void readCurrentAttributes(@Nonnull final InstanceIdentifier<VhostUser> id,
                                      @Nonnull final VhostUserBuilder builder,
                                      @Nonnull final ReadContext ctx) throws ReadFailedException {
        try {
            final InterfaceKey key = id.firstKeyOf(Interface.class);
            final int index = interfaceContext.getIndex(key.getName(), ctx.getMappingContext());
            if (!isInterfaceOfType(getFutureJVpp(), ctx.getModificationCache(), id, index,
                org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.v3po.rev150105.VhostUser.class)) {
                return;
            }

            LOG.debug("Reading attributes for vhpost user interface: {}", key.getName());

            @SuppressWarnings("unchecked")
            Map<Integer, SwInterfaceVhostUserDetails> mappedVhostUsers =
                (Map<Integer, SwInterfaceVhostUserDetails>) ctx.getModificationCache().get(DUMPED_VHOST_USERS_CONTEXT_KEY);

            if(mappedVhostUsers == null) {
                // Full VhostUser dump has to be performed here, no filter or anything is here to help so at least we cache it
                final SwInterfaceVhostUserDump request = new SwInterfaceVhostUserDump();
                final CompletionStage<SwInterfaceVhostUserDetailsReplyDump> swInterfaceVhostUserDetailsReplyDumpCompletionStage =
                    getFutureJVpp().swInterfaceVhostUserDump(request);
                final SwInterfaceVhostUserDetailsReplyDump reply =
                    TranslateUtils.getReply(swInterfaceVhostUserDetailsReplyDumpCompletionStage.toCompletableFuture());

                if(null == reply || null == reply.swInterfaceVhostUserDetails) {
                    mappedVhostUsers = Collections.emptyMap();
                } else {
                    final List<SwInterfaceVhostUserDetails> swInterfaceVhostUserDetails = reply.swInterfaceVhostUserDetails;
                    // Cache interfaces dump in per-tx context to later be used in readCurrentAttributes
                    mappedVhostUsers = swInterfaceVhostUserDetails.stream()
                        .collect(Collectors.toMap(t -> t.swIfIndex, swInterfaceDetails -> swInterfaceDetails));
                }

                ctx.getModificationCache().put(DUMPED_VHOST_USERS_CONTEXT_KEY, mappedVhostUsers);
            }

            // Relying here that parent InterfaceCustomizer was invoked first to fill in the context with initial ifc mapping
            final SwInterfaceVhostUserDetails swInterfaceVhostUserDetails = mappedVhostUsers.get(index);
            LOG.trace("Vhost user interface: {} attributes returned from VPP: {}", key.getName(), swInterfaceVhostUserDetails);

            builder.setRole(swInterfaceVhostUserDetails.isServer == 1 ? VhostUserRole.Server : VhostUserRole.Client);
            builder.setFeatures(BigInteger.valueOf(swInterfaceVhostUserDetails.features));
            builder.setNumMemoryRegions((long) swInterfaceVhostUserDetails.numRegions);
            builder.setSocket(TranslateUtils.toString(swInterfaceVhostUserDetails.sockFilename));
            builder.setVirtioNetHdrSize((long) swInterfaceVhostUserDetails.virtioNetHdrSz);
            builder.setConnectError(Integer.toString(swInterfaceVhostUserDetails.sockErrno));

            LOG.debug("Vhost user interface: {}, id: {} attributes read as: {}", key.getName(), index, builder);
        } catch (VppBaseCallException e) {
            LOG.warn("Failed to readCurrentAttributes for: {}", id, e);
            throw new ReadFailedException(id, e);
        }
    }
}