/*
 *
 * 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.socket;

import com.sun.jna.LastErrorException;
import com.sun.jna.Native;
import com.sun.jna.Platform;
import com.sun.jna.Structure;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.SocketAddress;
import java.util.Arrays;
import java.util.concurrent.atomic.AtomicBoolean;

public class UnixDomainSocket extends Socket {

  private static final int AF_UNIX = 1;
  private static final int SOCK_STREAM = Platform.isSolaris() ? 2 : 1;
  private static final int PROTOCOL = 0;

  static {
    if (Platform.isSolaris()) {
      System.loadLibrary("nsl");
      System.loadLibrary("socket");
    }
    if (!Platform.isWindows() && !Platform.isWindowsCE()) {
      Native.register("c");
    }
  }

  private final AtomicBoolean closeLock = new AtomicBoolean();
  private final SockAddr sockaddr;
  private final int fd;
  private InputStream is;
  private OutputStream os;
  private boolean connected;

  public UnixDomainSocket(String path) throws IOException {
    if (Platform.isWindows() || Platform.isWindowsCE()) {
      throw new IOException("Unix domain sockets are not supported on Windows");
    }
    sockaddr = new SockAddr(path);
    closeLock.set(false);
    try {
      fd = socket(AF_UNIX, SOCK_STREAM, PROTOCOL);
    } catch (LastErrorException lee) {
      throw new IOException("native socket() failed : " + formatError(lee));
    }
  }

  public static native int socket(int domain, int type, int protocol) throws LastErrorException;

  public static native int connect(int sockfd, SockAddr sockaddr, int addrlen)
      throws LastErrorException;

  public static native int recv(int fd, byte[] buffer, int count, int flags)
      throws LastErrorException;

  public static native int send(int fd, byte[] buffer, int count, int flags)
      throws LastErrorException;

  public static native int close(int fd) throws LastErrorException;

  public static native String strerror(int errno);

  private static String formatError(LastErrorException lee) {
    try {
      return strerror(lee.getErrorCode());
    } catch (Throwable t) {
      return lee.getMessage();
    }
  }

  @Override
  public boolean isConnected() {
    return connected;
  }

  @Override
  public void close() throws IOException {
    if (!closeLock.getAndSet(true)) {
      try {
        close(fd);
      } catch (LastErrorException lee) {
        throw new IOException("native close() failed : " + formatError(lee));
      }
      connected = false;
    }
  }

  @Override
  public void connect(SocketAddress endpoint) throws IOException {
    connect(endpoint, 0);
  }

  public void connect(SocketAddress endpoint, int timeout) throws IOException {
    try {
      int ret = connect(fd, sockaddr, sockaddr.size());
      if (ret != 0) {
        throw new IOException(strerror(Native.getLastError()));
      }
      connected = true;
    } catch (LastErrorException lee) {
      try {
        close();
      } catch (IOException e) {
      }
      throw new IOException("native connect() failed : " + formatError(lee));
    }
    is = new UnixSocketInputStream();
    os = new UnixSocketOutputStream();
  }

  public InputStream getInputStream() {
    return is;
  }

  public OutputStream getOutputStream() {
    return os;
  }

  public void setTcpNoDelay(boolean b) {
    // do nothing
  }

  public void setKeepAlive(boolean b) {
    // do nothing
  }

  public void setReceiveBufferSize(int size) {
    // do nothing
  }

  public void setSendBufferSize(int size) {
    // do nothing
  }

  public void setSoLinger(boolean b, int i) {
    // do nothing
  }

  public void setSoTimeout(int timeout) {
    // do nothing
  }

  public void shutdownInput() {
    // do nothing
  }

  public void shutdownOutput() {
    // do nothing
  }

  public static class SockAddr extends Structure {

    public short sun_family;
    public byte[] sun_path;

    /**
     * Contructor.
     *
     * @param sunPath path
     */
    public SockAddr(String sunPath) {
      sun_family = AF_UNIX;
      byte[] arr = sunPath.getBytes();
      sun_path = new byte[arr.length + 1];
      System.arraycopy(arr, 0, sun_path, 0, Math.min(sun_path.length - 1, arr.length));
      allocateMemory();
    }

    @Override
    protected java.util.List<String> getFieldOrder() {
      return Arrays.asList("sun_family", "sun_path");
    }
  }

  class UnixSocketInputStream extends InputStream {

    @Override
    public int read(byte[] bytesEntry, int off, int len) throws IOException {
      try {
        if (off > 0) {
          int bytes = 0;
          int remainingLength = len;
          int size;
          byte[] data = new byte[(len < 10240) ? len : 10240];
          do {
            size = recv(fd, data, (remainingLength < 10240) ? remainingLength : 10240, 0);
            if (size > 0) {
              System.arraycopy(data, 0, bytesEntry, off, size);
              bytes += size;
              off += size;
              remainingLength -= size;
            }
          } while ((remainingLength > 0) && (size > 0));
          return bytes;
        } else {
          return recv(fd, bytesEntry, len, 0);
        }
      } catch (LastErrorException lee) {
        throw new IOException("native read() failed : " + formatError(lee));
      }
    }

    @Override
    public int read() throws IOException {
      byte[] bytes = new byte[1];
      int bytesRead = read(bytes);
      if (bytesRead == 0) {
        return -1;
      }
      return bytes[0] & 0xff;
    }

    @Override
    public int read(byte[] bytes) throws IOException {
      return read(bytes, 0, bytes.length);
    }
  }

  class UnixSocketOutputStream extends OutputStream {

    @Override
    public void write(byte[] bytesEntry, int off, int len) throws IOException {
      int bytes;
      try {
        if (off > 0) {
          int size;
          int remainingLength = len;
          byte[] data = new byte[(len < 10240) ? len : 10240];
          do {
            size = (remainingLength < 10240) ? remainingLength : 10240;
            System.arraycopy(bytesEntry, off, data, 0, size);
            bytes = send(fd, data, size, 0);
            if (bytes > 0) {
              off += bytes;
              remainingLength -= bytes;
            }
          } while ((remainingLength > 0) && (bytes > 0));
        } else {
          bytes = send(fd, bytesEntry, len, 0);
        }

        if (bytes != len) {
          throw new IOException("can't write " + len + "bytes");
        }
      } catch (LastErrorException lee) {
        throw new IOException("native write() failed : " + formatError(lee));
      }
    }

    @Override
    public void write(int value) throws IOException {
      write(new byte[] {(byte) value});
    }

    @Override
    public void write(byte[] bytes) throws IOException {
      write(bytes, 0, bytes.length);
    }
  }
}
