/*
 * Copyright 2014 Open Networking Laboratory
 *
 * 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 org.onlab.packet.ndp;

import org.onlab.packet.BasePacket;
import org.onlab.packet.Data;
import org.onlab.packet.IPacket;
import org.onlab.packet.Ip6Address;

import java.nio.ByteBuffer;
import java.util.Arrays;

/**
 * Implements ICMPv6 Neighbor Solicitation packet format. (RFC 4861)
 */
public class NeighborSolicitation extends BasePacket {
    public static final byte HEADER_LENGTH = 20; // bytes

    protected byte[] targetAddress = new byte[Ip6Address.BYTE_LENGTH];

    /**
     * Gets target address.
     *
     * @return the target IPv6 address
     */
    public byte[] getTargetAddress() {
        return this.targetAddress;
    }

    /**
     * Sets target address.
     *
     * @param targetAddress the target IPv6 address to set
     * @return this
     */
    public NeighborSolicitation setTargetAddress(final byte[] targetAddress) {
        this.targetAddress = Arrays.copyOfRange(targetAddress, 0, Ip6Address.BYTE_LENGTH);
        return this;
    }

    @Override
    public byte[] serialize() {
        byte[] payloadData = null;
        if (this.payload != null) {
            this.payload.setParent(this);
            payloadData = this.payload.serialize();
        }

        int payloadLength = payloadData == null ? 0 : (short) payloadData.length;

        final byte[] data = new byte[HEADER_LENGTH + payloadLength];
        final ByteBuffer bb = ByteBuffer.wrap(data);

        bb.putInt(0);
        bb.put(this.targetAddress, 0, Ip6Address.BYTE_LENGTH);
        if (payloadData != null) {
            bb.put(payloadData);
        }

        return data;
    }

    @Override
    public IPacket deserialize(byte[] data, int offset, int length) {
        final ByteBuffer bb = ByteBuffer.wrap(data, offset, length);

        bb.getInt();
        bb.get(this.targetAddress, 0, Ip6Address.BYTE_LENGTH);

        this.payload = new Data();
        this.payload = this.payload.deserialize(data, bb.position(), bb.limit()
                - bb.position());
        this.payload.setParent(this);

        return this;
    }

    /*
     * (non-Javadoc)
     *
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        final int prime = 5807;
        int result = super.hashCode();
        ByteBuffer bb;
        bb = ByteBuffer.wrap(this.targetAddress);
        for (int i = 0; i < 4; i++) {
            result = prime * result + bb.getInt();
        }
        return result;
    }

    /*
     * (non-Javadoc)
     *
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }
        if (!super.equals(obj)) {
            return false;
        }
        if (!(obj instanceof NeighborSolicitation)) {
            return false;
        }
        final NeighborSolicitation other = (NeighborSolicitation) obj;
        if (!Arrays.equals(this.targetAddress, other.targetAddress)) {
            return false;
        }
        return true;
    }
}