/*
 * 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.translate.v3po.vppclassifier;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static io.fd.honeycomb.translate.v3po.interfacesstate.InterfaceUtils.printHexBinary;

import com.google.common.primitives.UnsignedInts;
import io.fd.honeycomb.translate.read.ReadContext;
import io.fd.honeycomb.translate.spi.read.ListReaderCustomizer;
import io.fd.honeycomb.translate.read.ReadFailedException;
import io.fd.honeycomb.translate.v3po.util.FutureJVppCustomizer;
import io.fd.honeycomb.translate.v3po.util.NamingContext;
import io.fd.honeycomb.translate.v3po.util.TranslateUtils;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;
import javax.annotation.Nonnull;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.HexString;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.classifier.rev150603.VppClassifierStateBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.classifier.rev150603.vpp.classifier.state.ClassifyTable;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.classifier.rev150603.vpp.classifier.state.ClassifyTableBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.vpp.classifier.rev150603.vpp.classifier.state.ClassifyTableKey;
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.ClassifyTableIds;
import org.openvpp.jvpp.dto.ClassifyTableIdsReply;
import org.openvpp.jvpp.dto.ClassifyTableInfo;
import org.openvpp.jvpp.dto.ClassifyTableInfoReply;
import org.openvpp.jvpp.future.FutureJVpp;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Reader customizer responsible for classify table read.<br> to VPP.<br> Equivalent to invoking {@code vppctl show
 * class table} command.
 */
public class ClassifyTableReader extends FutureJVppCustomizer
    implements ListReaderCustomizer<ClassifyTable, ClassifyTableKey, ClassifyTableBuilder>, VppNodeReader {

    private static final Logger LOG = LoggerFactory.getLogger(ClassifyTableReader.class);
    private final NamingContext classifyTableContext;

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


    @Override
    public void merge(@Nonnull final Builder<? extends DataObject> builder,
                      @Nonnull final List<ClassifyTable> readData) {
        ((VppClassifierStateBuilder) builder).setClassifyTable(readData);
    }

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

    @Override
    public void readCurrentAttributes(@Nonnull final InstanceIdentifier<ClassifyTable> id,
                                      @Nonnull final ClassifyTableBuilder builder, @Nonnull final ReadContext ctx)
        throws ReadFailedException {
        LOG.debug("Reading attributes for classify table: {}", id);

        final ClassifyTableKey key = id.firstKeyOf(ClassifyTable.class);
        checkArgument(key != null, "could not find ClassifyTable key in {}", id);
        final ClassifyTableInfo request = new ClassifyTableInfo();

        final String tableName = key.getName();
        if (!classifyTableContext.containsIndex(tableName, ctx.getMappingContext())) {
            LOG.debug("Could not find classify table {} in the naming context", tableName);
            return;
        }
        request.tableId = classifyTableContext.getIndex(tableName, ctx.getMappingContext());

        try {
            final ClassifyTableInfoReply reply =
                TranslateUtils.getReplyForRead(getFutureJVpp().classifyTableInfo(request).toCompletableFuture(), id);

            // mandatory values:
            builder.setName(tableName);
            builder.setKey(key);
            builder.setNbuckets(UnsignedInts.toLong(reply.nbuckets));
            builder.setSkipNVectors(UnsignedInts.toLong(reply.skipNVectors));


            builder.setMissNext(readVppNode(reply.missNextIndex, LOG));
            builder.setMask(new HexString(printHexBinary(reply.mask)));
            builder.setActiveSessions(UnsignedInts.toLong(reply.activeSessions));

            if (reply.nextTableIndex != ~0) {
                // next table index is present:
                builder.setNextTable(classifyTableContext.getName(reply.nextTableIndex, ctx.getMappingContext()));
            }

            if (LOG.isTraceEnabled()) {
                LOG.trace("Attributes for classify table {} successfully read: {}", id, builder.build());
            }
        } catch (VppBaseCallException e) {
            throw new ReadFailedException(id, e);
        }
    }

    @Nonnull
    @Override
    public List<ClassifyTableKey> getAllIds(@Nonnull final InstanceIdentifier<ClassifyTable> id,
                                            @Nonnull final ReadContext context) throws ReadFailedException {
        LOG.debug("Reading list of keys for classify tables: {}", id);
        try {
            final ClassifyTableIdsReply classifyTableIdsReply = TranslateUtils
                .getReplyForRead(getFutureJVpp().classifyTableIds(new ClassifyTableIds()).toCompletableFuture(), id);
            if (classifyTableIdsReply.ids != null) {
                return Arrays.stream(classifyTableIdsReply.ids).mapToObj(i -> {
                    final String tableName = classifyTableContext.getName(i, context.getMappingContext());
                    LOG.trace("Classify table with name: {} and index: {} found in VPP", tableName, i);
                    return new ClassifyTableKey(tableName);
                }).collect(Collectors.toList());
            } else {
                return Collections.emptyList();
            }
        } catch (VppBaseCallException e) {
            throw new ReadFailedException(id, e);
        }
    }
}