/*
    * 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.gateway.kernel.commonfile;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.ByteBufAllocator;
  import io.netty.buffer.Unpooled;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.handler.stream.ChunkedInput;
  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.FileInterface;
  import org.waarp.gateway.kernel.exception.HttpIncorrectRetrieveException;
  
  /**
   *
   */
  public class CommonFileChunkedInput implements ChunkedInput<ByteBuf> {
  
    private final FileInterface document;
  
    private boolean lastChunkAlready;
  
    private long offset;
  
    /**
     * @param document
     *
     * @throws HttpIncorrectRetrieveException
     */
    public CommonFileChunkedInput(final FileInterface document)
        throws HttpIncorrectRetrieveException {
      this.document = document;
      try {
        this.document.retrieve();
      } catch (final CommandAbstractException e) {
        throw new HttpIncorrectRetrieveException(e);
      }
    }
  
    @Override
    public final ByteBuf readChunk(final ChannelHandlerContext ctx)
        throws Exception {
      return readChunk(ByteBufAllocator.DEFAULT);
    }
  
    @Override
    public final long length() {
      try {
        return document.length();
      } catch (final CommandAbstractException e) {
        return -1;
      }
    }
  
    @Override
    public final long progress() {
      return offset;
    }
  
    @Override
    public final boolean isEndOfInput() {
      return lastChunkAlready;
    }
  
    @Override
    public final void close() throws HttpIncorrectRetrieveException {
      try {
        if (document.isInReading()) {
          document.abortFile();
        }
      } catch (final CommandAbstractException e) {
        throw new HttpIncorrectRetrieveException(e);
      }
      lastChunkAlready = true;
    }
  
    @Override
    public final ByteBuf readChunk(final ByteBufAllocator byteBufAllocator)
        throws Exception {
     // Document
     final DataBlock block;
     try {
       block = document.readDataBlock();
     } catch (final FileEndOfTransferException e) {
       lastChunkAlready = true;
       return Unpooled.EMPTY_BUFFER;
     } catch (final FileTransferException e) {
       throw new HttpIncorrectRetrieveException(e);
     }
     lastChunkAlready = block.isEOF();
     offset += block.getByteCount();
     final byte[] bytes = block.getByteBlock();
     final ByteBuf buffer = byteBufAllocator.buffer(bytes.length, bytes.length);
     buffer.writeBytes(bytes);
     return buffer;
   }
 }