/*
 * 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.lisp.translate.read;


import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;

import com.google.common.base.Optional;
import io.fd.honeycomb.lisp.translate.read.dump.check.LocatorDumpCheck;
import io.fd.honeycomb.lisp.translate.read.dump.executor.LocatorDumpExecutor;
import io.fd.honeycomb.lisp.translate.read.dump.executor.params.LocatorDumpParams;
import io.fd.honeycomb.translate.read.ReadContext;
import io.fd.honeycomb.translate.read.ReadFailedException;
import io.fd.honeycomb.translate.spi.read.ListReaderCustomizer;
import io.fd.honeycomb.translate.util.RWUtils;
import io.fd.honeycomb.translate.v3po.util.FutureJVppCustomizer;
import io.fd.honeycomb.translate.v3po.util.NamingContext;
import io.fd.honeycomb.translate.v3po.util.cache.DumpCacheManager;
import io.fd.honeycomb.translate.v3po.util.cache.exceptions.execution.DumpExecutionFailedException;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;
import javax.annotation.Nonnull;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.lisp.rev160520.locator.sets.grouping.locator.sets.LocatorSet;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.lisp.rev160520.locator.sets.grouping.locator.sets.LocatorSetBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.lisp.rev160520.locator.sets.grouping.locator.sets.locator.set.Interface;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.lisp.rev160520.locator.sets.grouping.locator.sets.locator.set.InterfaceBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.lisp.rev160520.locator.sets.grouping.locator.sets.locator.set.InterfaceKey;
import org.opendaylight.yangtools.concepts.Builder;
import org.opendaylight.yangtools.yang.binding.DataObject;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.openvpp.jvpp.core.dto.LispLocatorDetails;
import org.openvpp.jvpp.core.dto.LispLocatorDetailsReplyDump;
import org.openvpp.jvpp.core.future.FutureJVppCore;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * Customizer for reading {@code Interface}<br> Currently not supported by jvpp
 */
public class InterfaceCustomizer
        extends FutureJVppCustomizer
        implements ListReaderCustomizer<Interface, InterfaceKey, InterfaceBuilder> {

    private static final Logger LOG = LoggerFactory.getLogger(InterfaceCustomizer.class);
    private static final String KEY_BASE = InterfaceCustomizer.class.getName();

    private final NamingContext interfaceContext;
    private final NamingContext locatorSetContext;
    private final DumpCacheManager<LispLocatorDetailsReplyDump, LocatorDumpParams> dumpCacheManager;

    public InterfaceCustomizer(
            @Nonnull final FutureJVppCore futureJvpp,
            @Nonnull final NamingContext interfaceContext,
            @Nonnull final NamingContext locatorSetContext) {
        super(futureJvpp);
        this.interfaceContext = checkNotNull(interfaceContext, "Interface context cannot be null");
        this.locatorSetContext = checkNotNull(locatorSetContext, "Locator set context cannot be null");
        this.dumpCacheManager =
                new DumpCacheManager.DumpCacheManagerBuilder<LispLocatorDetailsReplyDump, LocatorDumpParams>()
                        .withExecutor(new LocatorDumpExecutor(futureJvpp))
                        .withNonEmptyPredicate(new LocatorDumpCheck())
                        .build();
    }

    @Override
    public InterfaceBuilder getBuilder(InstanceIdentifier<Interface> id) {
        return new InterfaceBuilder();
    }

    @Override
    public void readCurrentAttributes(InstanceIdentifier<Interface> id, InterfaceBuilder builder, ReadContext ctx)
            throws ReadFailedException {
        checkState(id.firstKeyOf(LocatorSet.class) != null, "Cannot find reference to parent locator set");
        final String name = id.firstKeyOf(LocatorSet.class).getName();

        checkState(locatorSetContext.containsIndex(name, ctx.getMappingContext()));
        final int interfaceIndex = locatorSetContext.getIndex(name, ctx.getMappingContext());
        final LocatorDumpParams params = new LocatorDumpParams.LocatorDumpParamsBuilder()
                .setFilter(LocatorDumpParams.LocatorDumpFilter.LOCAL)
                .setLocatorSetIndex(interfaceIndex)
                .build();

        Optional<LispLocatorDetailsReplyDump> reply;
        try {
            reply = dumpCacheManager.getDump(KEY_BASE, ctx.getModificationCache(), params);
        } catch (DumpExecutionFailedException e) {
            throw new ReadFailedException(id, e);
        }

        if (reply.isPresent()) {
            final LispLocatorDetails details = reply.get()
                    .lispLocatorDetails
                    .stream()
                    .filter(a -> a.swIfIndex == interfaceIndex)
                    .collect(RWUtils.singleItemCollector());

            final String interfaceRef = interfaceContext.getName(details.swIfIndex, ctx.getMappingContext());

            builder.setPriority(Byte.valueOf(details.priority).shortValue());
            builder.setWeight(Byte.valueOf(details.weight).shortValue());
            builder.setInterfaceRef(interfaceRef);
            builder.setKey(new InterfaceKey(interfaceRef));
        }
    }

    @Override
    public List<InterfaceKey> getAllIds(InstanceIdentifier<Interface> id, ReadContext context)
            throws ReadFailedException {

        checkState(id.firstKeyOf(LocatorSet.class) != null, "Cannot find reference to parent locator set");
        final String name = id.firstKeyOf(LocatorSet.class).getName();

        checkState(locatorSetContext.containsIndex(name, context.getMappingContext()), "No mapping for %s", name);
        final LocatorDumpParams params = new LocatorDumpParams.LocatorDumpParamsBuilder()
                .setFilter(LocatorDumpParams.LocatorDumpFilter.LOCAL)
                .setLocatorSetIndex(locatorSetContext.getIndex(name, context.getMappingContext()))
                .build();


        Optional<LispLocatorDetailsReplyDump> reply;
        try {
            reply = dumpCacheManager.getDump(KEY_BASE, context.getModificationCache(), params);
        } catch (DumpExecutionFailedException e) {
            throw new ReadFailedException(id, e);
        }

        if (reply.isPresent()) {
            return reply.get()
                    .lispLocatorDetails
                    .stream()
                    .map(a -> new InterfaceKey(interfaceContext.getName(a.swIfIndex, context.getMappingContext())))
                    .collect(Collectors.toList());
        } else {
            return Collections.emptyList();
        }
    }

    @Override
    public void merge(Builder<? extends DataObject> builder, List<Interface> readData) {
        ((LocatorSetBuilder) builder).setInterface(readData);
    }
}