/*
 * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.protocol.bgp.parser.impl.message.update;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
import org.opendaylight.protocol.bgp.parser.BGPError;
import org.opendaylight.protocol.bgp.parser.BGPTreatAsWithdrawException;
import org.opendaylight.protocol.bgp.parser.spi.AbstractAttributeParser;
import org.opendaylight.protocol.bgp.parser.spi.AttributeSerializer;
import org.opendaylight.protocol.bgp.parser.spi.AttributeUtil;
import org.opendaylight.protocol.bgp.parser.spi.PeerSpecificParserConstraint;
import org.opendaylight.protocol.bgp.parser.spi.RevisedErrorHandling;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev200120.path.attributes.Attributes;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev200120.path.attributes.AttributesBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev200120.path.attributes.attributes.MultiExitDisc;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev200120.path.attributes.attributes.MultiExitDiscBuilder;
import org.opendaylight.yangtools.yang.common.Uint32;
import org.opendaylight.yangtools.yang.common.netty.ByteBufUtils;

public final class MultiExitDiscriminatorAttributeParser extends AbstractAttributeParser
        implements AttributeSerializer {
    public static final int TYPE = 4;

    @Override
    public void parseAttribute(final ByteBuf buffer, final AttributesBuilder builder,
            final RevisedErrorHandling errorHandling, final PeerSpecificParserConstraint constraint)
                    throws BGPDocumentedException, BGPTreatAsWithdrawException {
        final int readable = buffer.readableBytes();
        if (readable != 4) {
            throw errorHandling.reportError(BGPError.ATTR_LENGTH_ERROR,
                "MULTI_EXIT_DISC has to have length 4, but has %s", readable);
        }
        builder.setMultiExitDisc(new MultiExitDiscBuilder().setMed(ByteBufUtils.readUint32(buffer)).build());
    }

    @Override
    public void serializeAttribute(final Attributes attribute, final ByteBuf byteAggregator) {
        final MultiExitDisc multiExitDisc = attribute.getMultiExitDisc();
        if (multiExitDisc != null) {
            final Uint32 med = multiExitDisc.getMed();
            if (med != null) {
                AttributeUtil.formatAttribute(AttributeUtil.OPTIONAL, TYPE, Unpooled.copyInt(med.intValue()),
                    byteAggregator);
            }
        }
    }
}