/*
    * This file is part of Waarp Project (named also Waarp or GG).
    *
    *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
    *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
    * individual contributors.
    *
    *  All Waarp Project is free software: you can redistribute it and/or
    * modify it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or (at your
   * option) any later version.
   *
   * Waarp 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 for more details.
   *
   *  You should have received a copy of the GNU General Public License along with
   * Waarp . If not, see <http://www.gnu.org/licenses/>.
   */
  package org.waarp.ftp.filesystembased;
  
  import io.netty.channel.Channel;
  import io.netty.channel.ChannelFuture;
  import org.waarp.common.command.exception.CommandAbstractException;
  import org.waarp.common.exception.FileEndOfTransferException;
  import org.waarp.common.exception.FileTransferException;
  import org.waarp.common.file.DataBlock;
  import org.waarp.common.file.filesystembased.FilesystemBasedFileImpl;
  import org.waarp.common.logging.WaarpLogger;
  import org.waarp.common.logging.WaarpLoggerFactory;
  import org.waarp.common.utility.WaarpNettyUtil;
  import org.waarp.ftp.core.exception.FtpNoConnectionException;
  import org.waarp.ftp.core.file.FtpFile;
  import org.waarp.ftp.core.session.FtpSession;
  
  import java.util.concurrent.locks.ReentrantLock;
  
  /**
   * Filesystem implementation of a FtpFile
   */
  public abstract class FilesystemBasedFtpFile extends FilesystemBasedFileImpl
      implements FtpFile {
    /**
     * Internal Logger
     */
    private static final WaarpLogger logger =
        WaarpLoggerFactory.getLogger(FilesystemBasedFtpFile.class);
  
    /**
     * Retrieve lock to ensure only one call at a time for one file
     */
    private final ReentrantLock retrieveLock = new ReentrantLock();
  
    /**
     * @param session
     * @param dir It is not necessary the directory that owns this file.
     * @param path
     * @param append
     *
     * @throws CommandAbstractException
     */
    protected FilesystemBasedFtpFile(final FtpSession session,
                                     final FilesystemBasedFtpDir dir,
                                     final String path, final boolean append)
        throws CommandAbstractException {
      super(session, dir, path, append);
    }
  
    @Override
    public final long length() throws CommandAbstractException {
      long length = super.length();
      if (((FtpSession) getSession()).getDataConn()
                                     .isFileStreamBlockAsciiImage()) {
        final long block = (long) Math.ceil(
            (double) length / (double) getSession().getBlockSize());
        length += (block + 3) * 3;
      }
      return length;
    }
  
    /**
     * Launch retrieve operation (internal method, should not be called
     * directly)
     */
    @Override
    public final void trueRetrieve() {
      retrieveLock.lock();
      try {
        if (!isReady) {
          return;
        }
        // First check if ready to run from Control
        try {
          ((FtpSession) session).getDataConn().getFtpTransferControl()
                                .waitForDataNetworkHandlerReady();
        } catch (final InterruptedException e) {//NOSONAR
          // bad thing
          logger.warn("DataNetworkHandler was not ready", e);
          if (isInReading()) {
           logger.error("Should not be", e);
           ((FtpSession) session).getDataConn().getFtpTransferControl()
                                 .setTransferAbortedFromInternal(true);
         }
         logger.debug(
             "Possible call while channel was on going to be closed once transfer was done",
             e);
         closeFile();
         ((FtpSession) session).getDataConn().getFtpTransferControl()
                               .setPreEndOfTransfer();
         return;
       }
       final Channel channel;
       try {
         channel = ((FtpSession) session).getDataConn().getCurrentDataChannel();
       } catch (final FtpNoConnectionException e) {
         if (isInReading()) {
           logger.error("Should not be", e);
           ((FtpSession) session).getDataConn().getFtpTransferControl()
                                 .setTransferAbortedFromInternal(true);
         }
         logger.debug(
             "Possible call while channel was on going to be closed once transfer was done",
             e);
         closeFile();
         ((FtpSession) session).getDataConn().getFtpTransferControl()
                               .setPreEndOfTransfer();
         return;
       }
       DataBlock block;
       try {
         block = readDataBlock();
       } catch (final FileEndOfTransferException e) {
         // Last block (in fact, previous block was the last one,
         // but it could be aligned with the block size so not
         // detected)
         closeFile();
         ((FtpSession) session).getDataConn().getFtpTransferControl()
                               .setPreEndOfTransfer();
         return;
       }
       if (block == null) {
         // Last block (in fact, previous block was the last one,
         // but it could be aligned with the block size so not
         // detected)
         closeFile();
         ((FtpSession) session).getDataConn().getFtpTransferControl()
                               .setPreEndOfTransfer();
         return;
       }
       // While not last block
       ChannelFuture future = null;
       while (block != null && !block.isEOF()) {
         future = channel.writeAndFlush(block);
         WaarpNettyUtil.awaitOrInterrupted(future);
         if (!future.isSuccess()) {
           closeFile();
           throw new FileTransferException("File transfer in error");
         }
         try {
           block = readDataBlock();
         } catch (final FileEndOfTransferException e) {
           closeFile();
           // Wait for last write
           if (future.isSuccess()) {
             ((FtpSession) session).getDataConn().getFtpTransferControl()
                                   .setPreEndOfTransfer();
           } else {
             throw new FileTransferException("File transfer in error");
           }
           return;
         }
       }
       // Last block
       closeFile();
       if (block != null) {
         logger.debug("Write {}", block.getByteCount());
         future = channel.writeAndFlush(block);
       }
       // Wait for last write
       if (future != null) {
         WaarpNettyUtil.awaitOrInterrupted(future);
         if (future.isSuccess()) {
           ((FtpSession) session).getDataConn().getFtpTransferControl()
                                 .setPreEndOfTransfer();
         } else {
           throw new FileTransferException("LAST Write is not successful",
                                           future.cause());
         }
       }
     } catch (final FileTransferException e) {
       // An error occurs!
       logger.error("File Transfer Exception: {}", e.getMessage(), e);
       ((FtpSession) session).getDataConn().getFtpTransferControl()
                             .setTransferAbortedFromInternal(true);
     } catch (final CommandAbstractException e) {
       logger.error("Should not be", e);
       ((FtpSession) session).getDataConn().getFtpTransferControl()
                             .setTransferAbortedFromInternal(true);
     } finally {
       retrieveLock.unlock();
     }
   }
 }