/*
 * Copyright 2015 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.onosproject.pcepio.types;

import java.util.Objects;

import org.jboss.netty.buffer.ChannelBuffer;
import org.onosproject.pcepio.protocol.PcepVersion;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.MoreObjects;
import com.google.common.base.MoreObjects.ToStringHelper;

/**
 * Provides IGP Link Metric .
 */
public class IGPMetricTlv implements PcepValueType {

    /* Reference :[I-D.ietf-idr-ls-distribution] /3.3.2.4
     *  0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |              Type=TDB40             |             Length      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     //      IGP Link Metric (variable length)      //
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     */

    protected static final Logger log = LoggerFactory.getLogger(IGPMetricTlv.class);

    public static final short TYPE = 1095; //TODO:NEED TO HANDLE TDB40
    private short hLength;

    private final byte[] rawValue;

    /**
     * Constructor to initialize raw value.
     *
     * @param rawValue IGP Link Metric
     * @param hLength length
     */
    public IGPMetricTlv(byte[] rawValue, short hLength) {
        this.rawValue = rawValue;
        this.hLength = hLength;
    }

    /**
     * Returns newly created IGPMetricTlv object.
     *
     * @param raw value of IGP Link Metric
     * @param hLength length
     * @return object of IGPMetricTlv
     */
    public static IGPMetricTlv of(final byte[] raw, short hLength) {
        return new IGPMetricTlv(raw, hLength);
    }

    /**
     * Returns value of IGP Link Metric.
     *
     * @return rawValue of IGP Link Metric
     */
    public byte[] getValue() {
        return rawValue;
    }

    @Override
    public PcepVersion getVersion() {
        return PcepVersion.PCEP_1;
    }

    @Override
    public short getType() {
        return TYPE;
    }

    @Override
    public short getLength() {
        return hLength;
    }

    @Override
    public int hashCode() {
        return Objects.hash(rawValue);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof IGPMetricTlv) {
            IGPMetricTlv other = (IGPMetricTlv) obj;
            return Objects.equals(rawValue, other.rawValue);
        }
        return false;
    }

    @Override
    public int write(ChannelBuffer c) {
        int iLenStartIndex = c.writerIndex();
        c.writeShort(TYPE);
        c.writeShort(hLength);
        c.writeBytes(rawValue);
        return c.writerIndex() - iLenStartIndex;
    }

    /**
     * Reads the channel buffer and returns object of IGPMetricTlv.
     *
     * @param c input channel buffer
     * @param hLength length
     * @return object of IGPMetricTlv
     */
    public static PcepValueType read(ChannelBuffer c, short hLength) {
        byte[] iIGPMetric = new byte[hLength];
        c.readBytes(iIGPMetric, 0, hLength);
        return new IGPMetricTlv(iIGPMetric, hLength);
    }

    @Override
    public String toString() {
        ToStringHelper toStrHelper = MoreObjects.toStringHelper(getClass());

        toStrHelper.add("Type", TYPE);
        toStrHelper.add("Length", hLength);

        StringBuffer result = new StringBuffer();
        for (byte b : rawValue) {
            result.append(String.format("%02X ", b));
        }
        toStrHelper.add("Value", result);

        return toStrHelper.toString();
    }
}