/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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;

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

/**
 *
 *
 */
public class LLDPTLV {
    protected byte type;
    protected short length;
    protected byte[] value;

    /**
     * @return the type
     */
    public byte getType() {
        return this.type;
    }

    /**
     * @param type
     *            the type to set
     */
    public LLDPTLV setType(final byte type) {
        this.type = type;
        return this;
    }

    /**
     * @return the length
     */
    public short getLength() {
        return this.length;
    }

    /**
     * @param length
     *            the length to set
     */
    public LLDPTLV setLength(final short length) {
        this.length = length;
        return this;
    }

    /**
     * @return the value
     */
    public byte[] getValue() {
        return this.value;
    }

    /**
     * @param value
     *            the value to set
     */
    public LLDPTLV setValue(final byte[] value) {
        this.value = value;
        return this;
    }

    public byte[] serialize() {
        // type = 7 bits
        // info string length 9 bits, each value == byte
        // info string
        final short scratch = (short) ((0x7f & this.type) << 9 | 0x1ff & this.length);
        final byte[] data = new byte[2 + this.length];
        final ByteBuffer bb = ByteBuffer.wrap(data);
        bb.putShort(scratch);
        if (this.value != null) {
            bb.put(this.value);
        }
        return data;
    }

    public LLDPTLV deserialize(final ByteBuffer bb) {
        short sscratch;
        sscratch = bb.getShort();
        this.type = (byte) (sscratch >> 9 & 0x7f);
        this.length = (short) (sscratch & 0x1ff);

        if (this.length > 0) {
            this.value = new byte[this.length];

            // if there is an underrun just toss the TLV
            if (bb.remaining() < this.length) {
                return null;
            }
            bb.get(this.value);
        }

        return this;
    }

    /*
     * (non-Javadoc)
     *
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        final int prime = 1423;
        int result = 1;
        result = prime * result + this.length;
        result = prime * result + this.type;
        result = prime * result + Arrays.hashCode(this.value);
        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 (obj == null) {
            return false;
        }
        if (!(obj instanceof LLDPTLV)) {
            return false;
        }
        final LLDPTLV other = (LLDPTLV) obj;
        if (this.length != other.length) {
            return false;
        }
        if (this.type != other.type) {
            return false;
        }
        if (!Arrays.equals(this.value, other.value)) {
            return false;
        }
        return true;
    }
}