/*

 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.io.ByteArrayInputStream;

import java.io.DataInputStream;

import java.io.IOException;

import java.io.InputStream;

/**

 * Generic JDWP reply

 */

public abstract class JdwpReply {

    protected final static int HEADER_LEN = 11;

    private byte[] errCode = new byte[2];

    private byte[] data;

    public final void initFromStream(InputStream is) throws IOException {

        DataInputStream ds = new DataInputStream(is);

        int length = ds.readInt();

        int id = ds.readInt();

        byte flags = (byte) ds.read();

        ds.read(errCode, 0, 2);

        int dataLength = length - HEADER_LEN;

        if (dataLength > 0) {

            data = new byte[dataLength];

            int bytesRead = ds.read(data, 0, dataLength);

            // For large data JDWP agent sends two packets: 1011 bytes in

            // the first packet (1000 + HEADER_LEN) and the rest in the

            // second packet.

            if (bytesRead > 0 && bytesRead < dataLength) {

                System.out.println("[" + getClass().getName() + "] Only " +

                        bytesRead + " bytes of " + dataLength + " were " +

                        "read in the first packet. Reading the rest...");

                ds.read(data, bytesRead, dataLength - bytesRead);

            }

            parseData(new DataInputStream(new ByteArrayInputStream(data)));

        }

    }

    protected void parseData(DataInputStream ds) throws IOException {

    }

    protected byte[] readJdwpString(DataInputStream ds) throws IOException {

        byte[] str = null;

        int len = ds.readInt();

        if (len > 0) {

            str = new byte[len];

            ds.read(str, 0, len);

        }

        return str;

    }

    protected long readRefId(DataInputStream ds) throws IOException {

        return ds.readLong();

    }

    public int getErrorCode() {

        return (((errCode[0] & 0xFF) << 8) | (errCode[1] & 0xFF));

    }

}