/*
    * 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.core.control;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.channel.ChannelInitializer;
  import io.netty.channel.ChannelPipeline;
  import io.netty.channel.socket.SocketChannel;
  import io.netty.handler.codec.DelimiterBasedFrameDecoder;
  import io.netty.util.concurrent.EventExecutorGroup;
  import org.waarp.common.command.ReplyCode;
  import org.waarp.common.utility.WaarpNettyUtil;
  import org.waarp.common.utility.WaarpStringUtils;
  import org.waarp.ftp.core.config.FtpConfiguration;
  import org.waarp.ftp.core.session.FtpSession;
  
  /**
   * Pipeline factory for Control command connection
   */
  public class FtpInitializer extends ChannelInitializer<SocketChannel> {
    /**
     * CRLF, CRNUL, LF delimiters
     */
    protected static final ByteBuf[] delimiter = {
        WaarpNettyUtil.wrappedBuffer(
            ReplyCode.CRLF.getBytes(WaarpStringUtils.UTF8)),
        WaarpNettyUtil.wrappedBuffer(
            ReplyCode.CRNUL.getBytes(WaarpStringUtils.UTF8)),
        WaarpNettyUtil.wrappedBuffer(ReplyCode.LF.getBytes(WaarpStringUtils.UTF8))
    };
  
    protected static final FtpControlStringDecoder ftpControlStringDecoder =
        new FtpControlStringDecoder(WaarpStringUtils.UTF8);
  
    protected static final FtpControlStringEncoder ftpControlStringEncoder =
        new FtpControlStringEncoder(WaarpStringUtils.UTF8);
  
    /**
     * Business Handler Class if any (Target Mode only)
     */
    protected final Class<? extends BusinessHandler> businessHandler;
  
    /**
     * Configuration
     */
    protected final FtpConfiguration configuration;
  
    /**
     * Constructor which Initializes some data for Server only
     *
     * @param businessHandler
     * @param configuration
     */
    public FtpInitializer(final Class<? extends BusinessHandler> businessHandler,
                          final FtpConfiguration configuration) {
      this.businessHandler = businessHandler;
      this.configuration = configuration;
    }
  
    /**
     * Create the pipeline with Handler, ObjectDecoder, ObjectEncoder.
     */
    @Override
    public void initChannel(final SocketChannel ch) throws Exception {
      final ChannelPipeline pipeline = ch.pipeline();
      // Add the text line codec combination first,
      pipeline.addLast("framer", new DelimiterBasedFrameDecoder(8192, delimiter));
      pipeline.addLast("decoder", ftpControlStringDecoder);
      pipeline.addLast("encoder", ftpControlStringEncoder);
      // Threaded execution for business logic
      final EventExecutorGroup executorGroup =
          configuration.getFtpInternalConfiguration().getExecutor();
      // and then business logic. New one on every connection
      final BusinessHandler newbusiness =
          businessHandler.getDeclaredConstructor().newInstance();
      final NetworkHandler newNetworkHandler =
          new NetworkHandler(new FtpSession(configuration, newbusiness));
      pipeline.addLast(executorGroup, "handler", newNetworkHandler);
    }
  }