/*
 *
 * MariaDB Client for Java
 *
 * Copyright (c) 2012-2014 Monty Program Ab.
 * Copyright (c) 2015-2020 MariaDB Corporation Ab.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this library; if not, write to Monty Program Ab info@montyprogram.com.
 *
 * This particular MariaDB Client for Java file is work
 * derived from a Drizzle-JDBC. Drizzle-JDBC file which is covered by subject to
 * the following copyright and notice provisions:
 *
 * Copyright (c) 2009-2011, Marcus Eriksson
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * Redistributions of source code must retain the above copyright notice, this list
 * of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice, this
 * list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
 *
 * Neither the name of the driver nor the names of its contributors may not be
 * used to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS  AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 */

package org.mariadb.jdbc.internal.io.output;

import static org.mariadb.jdbc.internal.io.TraceObject.COMPRESSED_PROTOCOL_COMPRESSED_PACKET;
import static org.mariadb.jdbc.internal.io.TraceObject.COMPRESSED_PROTOCOL_NOT_COMPRESSED_PACKET;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.zip.DeflaterOutputStream;
import org.mariadb.jdbc.internal.io.TraceObject;
import org.mariadb.jdbc.internal.logging.Logger;
import org.mariadb.jdbc.internal.logging.LoggerFactory;
import org.mariadb.jdbc.internal.util.Utils;

public class CompressPacketOutputStream extends AbstractPacketOutputStream {

  private static final Logger logger = LoggerFactory.getLogger(CompressPacketOutputStream.class);

  private static final int MAX_PACKET_LENGTH = 0x00ffffff;
  private static final byte[] EMPTY_ARRAY = new byte[0];
  private static final int MIN_COMPRESSION_SIZE = 100;
  private static final float MIN_COMPRESSION_RATIO = 0.9f;
  private final byte[] header = new byte[7];
  private final byte[] subHeader = new byte[4];
  private int maxPacketLength = MAX_PACKET_LENGTH;
  private int compressSeqNo;
  private byte[] remainingData = new byte[0];
  private boolean lastPacketExactMaxPacketLength = false;

  public CompressPacketOutputStream(OutputStream out, int maxQuerySizeToLog, long threadId) {
    super(out, maxQuerySizeToLog, threadId);
  }

  public int getMaxPacketLength() {
    return maxPacketLength;
  }

  @Override
  public void setMaxAllowedPacket(int maxAllowedPacket) {
    this.maxAllowedPacket = maxAllowedPacket;
    maxPacketLength = Math.min(MAX_PACKET_LENGTH, maxAllowedPacket + 7);
  }

  @Override
  public void startPacket(int compressSeqNo) {
    this.compressSeqNo = compressSeqNo;
    this.seqNo = 0;
    pos = 0;
    cmdLength = 0;
    remainingData = EMPTY_ARRAY;
    lastPacketExactMaxPacketLength = false;
  }

  public int initialPacketPos() {
    return 0;
  }

  /**
   * Flush the internal buffer.
   *
   * <p>Compression add a 7 header :
   *
   * <ol>
   *   <li>3 byte compression length
   *   <li>1 byte compress sequence number
   *   <li>3 bytes uncompress length
   * </ol>
   *
   * <p>in case packet isn't compressed (last 3 bytes == 0):
   *
   * <ol>
   *   <li>3 byte uncompress length
   *   <li>1 byte compress sequence number
   *   <li>3 bytes with 0 value
   * </ol>
   *
   * <p>Content correspond to standard content.
   *
   * <ol>
   *   <li>3 byte length
   *   <li>1 byte sequence number (!= than compress sequence number)
   *   <li>sub-content
   * </ol>
   *
   * <p>Problem is when standard content is bigger than 16mb : content will not send 4byte standard
   * header + 16mb content, since packet are limited to 16mb then 4 bytes standard header + 16mb - 4
   * bytes content. the ending 4 bytes are waiting to be send. next packet will then send the
   * waiting data before next packet, putting more waiting data is needed. if ending data is exactly
   * MAX_PACKET_LENGTH length, then an empty packet must be send.
   *
   * @param commandEnd command end
   * @throws IOException id connection error occur.
   */
  protected void flushBuffer(boolean commandEnd) throws IOException {
    if (pos > 0) {
      if (pos + remainingData.length > MIN_COMPRESSION_SIZE) {

        byte[] compressedBytes;
        int uncompressSize = Math.min(MAX_PACKET_LENGTH, remainingData.length + 4 + pos);
        checkMaxAllowedLength(uncompressSize);

        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
          try (DeflaterOutputStream deflater = new DeflaterOutputStream(baos)) {
            if (remainingData.length != 0) {
              deflater.write(remainingData);
            }
            subHeader[0] = (byte) pos;
            subHeader[1] = (byte) (pos >>> 8);
            subHeader[2] = (byte) (pos >>> 16);
            subHeader[3] = (byte) this.seqNo++;

            deflater.write(subHeader, 0, 4);
            deflater.write(buf, 0, uncompressSize - (remainingData.length + 4));
            deflater.finish();
          }

          compressedBytes = baos.toByteArray();

          if (compressedBytes.length < (int) (MIN_COMPRESSION_RATIO * pos)) {
            int compressedLength = compressedBytes.length;

            header[0] = (byte) compressedLength;
            header[1] = (byte) (compressedLength >>> 8);
            header[2] = (byte) (compressedLength >>> 16);
            header[3] = (byte) this.compressSeqNo++;
            header[4] = (byte) uncompressSize;
            header[5] = (byte) (uncompressSize >>> 8);
            header[6] = (byte) (uncompressSize >>> 16);
            out.write(header, 0, 7);
            out.write(compressedBytes, 0, compressedLength);
            cmdLength += uncompressSize;

            if (traceCache != null) {
              // trace last packets
              if (remainingData.length != 0) {
                traceCache.put(
                    new TraceObject(
                        true,
                        COMPRESSED_PROTOCOL_COMPRESSED_PACKET,
                        threadId,
                        Arrays.copyOfRange(header, 0, 7),
                        Arrays.copyOfRange(remainingData, 0, remainingData.length),
                        Arrays.copyOfRange(subHeader, 0, 4),
                        Arrays.copyOfRange(
                            buf,
                            0,
                            (uncompressSize > 1000 ? 1000 : uncompressSize)
                                - (remainingData.length + 4))));
              } else {
                traceCache.put(
                    new TraceObject(
                        true,
                        COMPRESSED_PROTOCOL_COMPRESSED_PACKET,
                        threadId,
                        Arrays.copyOfRange(header, 0, 7),
                        Arrays.copyOfRange(subHeader, 0, 4),
                        Arrays.copyOfRange(
                            buf,
                            0,
                            (uncompressSize > 1000 ? 1000 : uncompressSize)
                                - (remainingData.length + 4))));
              }
            }

            if (logger.isTraceEnabled()) {
              if (remainingData.length != 0) {
                logger.trace(
                    "send compress: {}{}",
                    serverThreadLog,
                    Utils.hexdump(
                        maxQuerySizeToLog - (remainingData.length + 11),
                        0,
                        compressedLength,
                        header,
                        remainingData,
                        subHeader,
                        buf));
              } else {
                logger.trace(
                    "send compress: {}{}",
                    serverThreadLog,
                    Utils.hexdump(
                        maxQuerySizeToLog - 11, 0, compressedLength, header, subHeader, buf));
              }
            }
            if (pos + remainingData.length + 4 - uncompressSize > 0) {
              remainingData =
                  Arrays.copyOfRange(buf, uncompressSize - (remainingData.length + 4), pos);
            } else {
              remainingData = EMPTY_ARRAY;
            }

            // if last packet fill the max size, must send an empty packet to indicate command end.
            lastPacketExactMaxPacketLength = pos == MAX_PACKET_LENGTH;
            if (commandEnd && lastPacketExactMaxPacketLength) {
              writeEmptyPacket();
            }
            pos = 0;
            return;
          } else {
            // reset sequence to previous value, since not sent because compression wasn't high
            // enough
            this.seqNo--;
          }
        }
      }

      int uncompressSize = Math.min(MAX_PACKET_LENGTH, remainingData.length + 4 + pos);
      checkMaxAllowedLength(uncompressSize);
      cmdLength += uncompressSize;

      // send packet without compression
      header[0] = (byte) uncompressSize;
      header[1] = (byte) (uncompressSize >>> 8);
      header[2] = (byte) (uncompressSize >>> 16);
      header[3] = (byte) this.compressSeqNo++;
      header[4] = (byte) 0x00;
      header[5] = (byte) 0x00;
      header[6] = (byte) 0x00;
      out.write(header, 0, 7);

      cmdLength += uncompressSize;

      if (remainingData.length != 0) {
        out.write(remainingData);
      }
      subHeader[0] = (byte) pos;
      subHeader[1] = (byte) (pos >>> 8);
      subHeader[2] = (byte) (pos >>> 16);
      subHeader[3] = (byte) this.seqNo++;

      out.write(subHeader, 0, 4);
      out.write(buf, 0, uncompressSize - (remainingData.length + 4));
      cmdLength += remainingData.length;

      if (traceCache != null) {
        // trace last packets
        if (remainingData.length != 0) {
          traceCache.put(
              new TraceObject(
                  true,
                  COMPRESSED_PROTOCOL_NOT_COMPRESSED_PACKET,
                  threadId,
                  Arrays.copyOfRange(header, 0, 7),
                  Arrays.copyOfRange(remainingData, 0, remainingData.length),
                  Arrays.copyOfRange(subHeader, 0, 4),
                  Arrays.copyOfRange(
                      buf,
                      0,
                      (uncompressSize > 1000 ? 1000 : uncompressSize)
                          - (remainingData.length + 4))));
        } else {
          traceCache.put(
              new TraceObject(
                  true,
                  COMPRESSED_PROTOCOL_NOT_COMPRESSED_PACKET,
                  threadId,
                  Arrays.copyOfRange(header, 0, 7),
                  Arrays.copyOfRange(subHeader, 0, 4),
                  Arrays.copyOfRange(
                      buf,
                      0,
                      (uncompressSize > 1000 ? 1000 : uncompressSize)
                          - (remainingData.length + 4))));
        }
      }

      if (logger.isTraceEnabled()) {
        if (remainingData.length != 0) {
          logger.trace(
              "send uncompress: {}{}",
              serverThreadLog,
              Utils.hexdump(
                  maxQuerySizeToLog - (remainingData.length + 11),
                  0,
                  pos,
                  header,
                  remainingData,
                  subHeader,
                  buf));
        } else {
          logger.trace(
              "send uncompress: {}{}",
              serverThreadLog,
              Utils.hexdump(maxQuerySizeToLog - 11, 0, pos + 4, header, subHeader, buf));
        }
      }

      if (pos + remainingData.length + 4 - uncompressSize > 0) {
        remainingData = Arrays.copyOfRange(buf, uncompressSize - (remainingData.length + 4), pos);
      } else {
        remainingData = EMPTY_ARRAY;
      }

      // if last packet fill the max size, must send an empty packet to indicate command end.
      lastPacketExactMaxPacketLength = pos == MAX_PACKET_LENGTH;
      pos = 0;
    }

    if (remainingData.length > 0) {
      if (remainingData.length > MIN_COMPRESSION_SIZE) {

        byte[] compressedBytes;
        int uncompressSize = Math.min(MAX_PACKET_LENGTH, remainingData.length);
        checkMaxAllowedLength(uncompressSize);
        cmdLength += uncompressSize;
        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
          try (DeflaterOutputStream deflater = new DeflaterOutputStream(baos)) {
            deflater.write(remainingData);
            deflater.finish();
          }
          compressedBytes = baos.toByteArray();
          remainingData = EMPTY_ARRAY;
        }

        if (compressedBytes.length < (int) (MIN_COMPRESSION_RATIO * pos)) {
          int compressedLength = compressedBytes.length;

          header[0] = (byte) compressedLength;
          header[1] = (byte) (compressedLength >>> 8);
          header[2] = (byte) (compressedLength >>> 16);
          header[3] = (byte) this.compressSeqNo++;
          header[4] = (byte) uncompressSize;
          header[5] = (byte) (uncompressSize >>> 8);
          header[6] = (byte) (uncompressSize >>> 16);
          out.write(header, 0, 7);
          out.write(compressedBytes, 0, compressedLength);

          if (traceCache != null) {
            traceCache.put(
                new TraceObject(
                    true,
                    COMPRESSED_PROTOCOL_COMPRESSED_PACKET,
                    threadId,
                    Arrays.copyOfRange(header, 0, 7),
                    Arrays.copyOfRange(
                        remainingData, 0, (uncompressSize > 1000 ? 1000 : uncompressSize))));
          }

          if (logger.isTraceEnabled()) {
            logger.trace(
                "send compress: {}{}",
                serverThreadLog,
                Utils.hexdump(maxQuerySizeToLog - 7, 0, uncompressSize, header, remainingData));
          }

          // if last packet fill the max size, must send an empty packet to indicate command end.
          if (commandEnd && lastPacketExactMaxPacketLength) {
            writeEmptyPacket();
          }
          return;
        }
      }

      int uncompressSize = Math.min(MAX_PACKET_LENGTH, remainingData.length);
      checkMaxAllowedLength(uncompressSize);
      cmdLength += uncompressSize;

      // send packet without compression
      header[0] = (byte) uncompressSize;
      header[1] = (byte) (uncompressSize >>> 8);
      header[2] = (byte) (uncompressSize >>> 16);
      header[3] = (byte) this.compressSeqNo++;
      header[4] = (byte) 0x00;
      header[5] = (byte) 0x00;
      header[6] = (byte) 0x00;
      out.write(header, 0, 7);

      out.write(remainingData);
      remainingData = EMPTY_ARRAY;

      if (traceCache != null) {
        traceCache.put(
            new TraceObject(
                true,
                COMPRESSED_PROTOCOL_NOT_COMPRESSED_PACKET,
                threadId,
                Arrays.copyOfRange(header, 0, 7),
                Arrays.copyOfRange(
                    remainingData,
                    0,
                    (remainingData.length > 1000 ? 1000 : remainingData.length))));
      }

      if (logger.isTraceEnabled()) {
        logger.trace(
            "send uncompress: {}{}",
            serverThreadLog,
            Utils.hexdump(maxQuerySizeToLog - 7, 0, remainingData.length, header, remainingData));
      }
      if (commandEnd && lastPacketExactMaxPacketLength) {
        writeEmptyPacket();
      }
    }
  }

  /**
   * Write an empty packet.
   *
   * @throws IOException if socket error occur.
   */
  public void writeEmptyPacket() throws IOException {
    buf[0] = (byte) 4;
    buf[1] = (byte) 0x00;
    buf[2] = (byte) 0x00;
    buf[3] = (byte) this.compressSeqNo++;
    buf[4] = (byte) 0x00;
    buf[5] = (byte) 0x00;
    buf[6] = (byte) 0x00;
    buf[7] = (byte) 0x00;
    buf[8] = (byte) 0x00;
    buf[9] = (byte) 0x00;
    buf[10] = (byte) this.seqNo++;
    out.write(buf, 0, 11);

    if (traceCache != null) {
      traceCache.put(
          new TraceObject(
              true,
              COMPRESSED_PROTOCOL_NOT_COMPRESSED_PACKET,
              threadId,
              Arrays.copyOfRange(buf, 0, 11)));
    }

    if (logger.isTraceEnabled()) {
      logger.trace(
          "send uncompress:{}{}", serverThreadLog, Utils.hexdump(maxQuerySizeToLog, 0, 11, buf));
    }
  }
}
