/*
 * (C) 2007-2012 Alibaba Group Holding Limited.
 * 
 * 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.
 * Authors:
 *   wuhua <wq163@163.com> , boyan <killme2008@gmail.com>
 */
package com.taobao.metamorphosis.network;

import java.util.Arrays;

import com.taobao.gecko.core.buffer.IoBuffer;


/**
 * Ӧ�����Э���ʽ���£� value total-length opaque\r\n data,����data�Ľṹ���£�
 * <ul>
 * <li>4���ֽڵ���Ϣ���ݳ��ȣ����ܰ������ԣ�</li>
 * <li>4���ֽڵ�check sum</li>
 * <li>8���ֽڵ���Ϣid</li>
 * <li>4���ֽڵ�flag</li>
 * <li>��Ϣ���ݣ���������ԣ���Ϊ��
 * <ul>
 * <li>4���ֽڵ����Գ���+ ��Ϣ���� + payload</li>
 * </ul>
 * </li> ������
 * <ul>
 * <li>payload</li>
 * <ul>
 * </li>
 * </ul>
 * 
 * @author boyan
 * @Date 2011-4-19
 * 
 */
public class DataCommand extends AbstractResponseCommand {
    private final byte[] data;
    static final long serialVersionUID = -1L;
    private boolean encodeHeader = false;


    @Override
    public int hashCode() {
        final int prime = 31;
        int result = super.hashCode();
        result = prime * result + Arrays.hashCode(this.data);
        result = prime * result + (this.encodeHeader ? 1231 : 1237);
        return result;
    }


    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (!super.equals(obj)) {
            return false;
        }
        if (this.getClass() != obj.getClass()) {
            return false;
        }
        DataCommand other = (DataCommand) obj;
        if (!Arrays.equals(this.data, other.data)) {
            return false;
        }
        if (this.encodeHeader != other.encodeHeader) {
            return false;
        }
        return true;
    }


    public byte[] getData() {
        return this.data;
    }


    public DataCommand(final byte[] data, final Integer opaque) {
        this(data, opaque, false);
    }


    public DataCommand(final byte[] data, final Integer opaque, boolean encodeHeader) {
        super(opaque);
        this.data = data;
        this.encodeHeader = encodeHeader;
    }


    @Override
    public boolean isBoolean() {
        return false;
    }


    @Override
    public final IoBuffer encode() {
        if (this.encodeHeader) {
            int totalDataLength = this.data != null ? this.data.length : 0;
            final IoBuffer buffer =
                    IoBuffer.allocate(9 + ByteUtils.stringSize(totalDataLength)
                        + ByteUtils.stringSize(this.getOpaque()) + totalDataLength);
            ByteUtils.setArguments(buffer, MetaEncodeCommand.VALUE_CMD, totalDataLength, this.getOpaque());
            if (this.data != null) {
                buffer.put(this.data);
            }
            buffer.flip();
            return buffer;
        }
        else {
            // We don't encode header,it is done by message set.
            return null;
        }
    }

}