/*
 * 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;

import com.google.common.primitives.UnsignedBytes;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import java.util.Arrays;
import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
import org.opendaylight.protocol.bgp.parser.BGPError;
import org.opendaylight.protocol.bgp.parser.spi.MessageParser;
import org.opendaylight.protocol.bgp.parser.spi.MessageSerializer;
import org.opendaylight.protocol.bgp.parser.spi.MessageUtil;
import org.opendaylight.protocol.util.ByteArray;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Notify;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.NotifyBuilder;
import org.opendaylight.yangtools.yang.binding.Notification;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Parser for BGPNotification message.
 */
public final class BGPNotificationMessageParser implements MessageParser, MessageSerializer {

    public static final int TYPE = 3;

    private static final Logger LOG = LoggerFactory.getLogger(BGPNotificationMessageParser.class);

    private static final int ERROR_SIZE = 2;

    /**
     * Serializes BGP Notification message.
     *
     * @param msg to be serialized
     * @return BGP Notification message converted to byte array
     */
    @Override
    public void serializeMessage(final Notification msg, ByteBuf bytes) {
        if (msg == null) {
            throw new IllegalArgumentException("BGP Notification message cannot be null");
        }

        final Notify ntf = (Notify) msg;
        LOG.trace("Started serializing Notification message: {}", ntf);

        final byte[] msgBody = (ntf.getData() == null) ? new byte[ERROR_SIZE] : new byte[ERROR_SIZE + ntf.getData().length];

        msgBody[0] = UnsignedBytes.checkedCast(ntf.getErrorCode());

        msgBody[1] = UnsignedBytes.checkedCast(ntf.getErrorSubcode());

        if (ntf.getData() != null) {
            System.arraycopy(ntf.getData(), 0, msgBody, ERROR_SIZE, ntf.getData().length);
        }

        bytes.writeBytes(MessageUtil.formatMessage(TYPE, msgBody));
        LOG.trace("Notification message serialized to: {}", ByteBufUtil.hexDump(bytes));
    }

    /**
     * Parses BGP Notification message to bytes.
     *
     * @param body byte array to be parsed
     * @return BGPNotification message
     * @throws BGPDocumentedException
     */
    @Override
    public Notify parseMessageBody(final ByteBuf body, final int messageLength) throws BGPDocumentedException {
        if (body == null) {
            throw new IllegalArgumentException("Byte array cannot be null.");
        }
        LOG.trace("Started parsing of notification message: {}", Arrays.toString(ByteArray.getAllBytes(body)));

        if (body.readableBytes() < ERROR_SIZE) {
            throw BGPDocumentedException.badMessageLength("Notification message too small.", messageLength);
        }
        final int errorCode = UnsignedBytes.toInt(body.readByte());
        final int errorSubcode = UnsignedBytes.toInt(body.readByte());

        byte[] data = null;
        if (body.readableBytes() != 0) {
            data = ByteArray.readAllBytes(body);
        }
        final NotifyBuilder builder = new NotifyBuilder().setErrorCode((short) errorCode).setErrorSubcode((short) errorSubcode);
        if (data != null) {
            builder.setData(data);
        }
        LOG.debug("BGP Notification message was parsed: err = {}, data = {}.", BGPError.forValue(errorCode, errorSubcode),
                Arrays.toString(data));
        return builder.build();
    }
}