/*
 * 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 static org.opendaylight.protocol.util.Ipv4Util.IP4_LENGTH;
import static org.opendaylight.protocol.util.Ipv6Util.IPV6_LENGTH;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import org.opendaylight.bgp.concepts.NextHopUtil;
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.types.rev200120.next.hop.CNextHop;

public final class NextHopAttributeParser extends AbstractAttributeParser implements AttributeSerializer {
    public static final int TYPE = 3;

    @Override
    public void parseAttribute(final ByteBuf buffer, final AttributesBuilder builder,
            final RevisedErrorHandling errorHandling, final PeerSpecificParserConstraint constraint)
                    throws BGPDocumentedException, BGPTreatAsWithdrawException {
        final int readable = buffer.readableBytes();
        final CNextHop nextHop;
        switch (readable) {
            case IP4_LENGTH:
                nextHop = NextHopUtil.parseNextHopIpv4(buffer);
                break;
            case IPV6_LENGTH:
                nextHop = NextHopUtil.parseNextHopIpv6(buffer);
                break;
            case IPV6_LENGTH * 2:
                nextHop = NextHopUtil.parseNextHopFullIpv6(buffer);
                break;
            default:
                throw errorHandling.reportError(BGPError.ATTR_LENGTH_ERROR,
                    "NEXT_HOP attribute is expected to have length of {%s, %s, %s} but has %s", IP4_LENGTH, IPV6_LENGTH,
                    IPV6_LENGTH * 2, readable);
        }

        builder.setCNextHop(nextHop);
    }

    @Override
    public void serializeAttribute(final Attributes attribute, final ByteBuf byteAggregator) {
        final CNextHop cNextHop = attribute.getCNextHop();
        if (cNextHop != null) {
            final ByteBuf nextHopBuffer = Unpooled.buffer();
            NextHopUtil.serializeNextHop(cNextHop, nextHopBuffer);
            AttributeUtil.formatAttribute(AttributeUtil.TRANSITIVE, TYPE, nextHopBuffer, byteAggregator);
        }
    }
}