/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.tajo.rpc;

import com.google.protobuf.MessageLite;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.protobuf.ProtobufDecoder;
import io.netty.handler.codec.protobuf.ProtobufEncoder;
import io.netty.handler.codec.protobuf.ProtobufVarint32FrameDecoder;
import io.netty.handler.codec.protobuf.ProtobufVarint32LengthFieldPrepender;
import io.netty.handler.timeout.IdleStateHandler;

import java.util.concurrent.TimeUnit;

class ProtoClientChannelInitializer extends ChannelInitializer<Channel> {
  private final MessageLite defaultInstance;
  private final ChannelHandler handler;
  private final long idleTimeout;
  private final boolean hangDetection;

  /**
   * Channel Pipe Initializer
   *
   * @param handler          Channel Handler
   * @param defaultInstance  Default Rpc Proto instance
   * @param idleTimeout      Idle timeout (milliseconds)
   */
  public ProtoClientChannelInitializer(ChannelHandler handler, MessageLite defaultInstance,
                                       long idleTimeout, boolean hangDetection) {
    this.handler = handler;
    this.defaultInstance = defaultInstance;
    this.idleTimeout = idleTimeout;
    this.hangDetection = hangDetection;
  }

  @Override
  protected void initChannel(Channel channel) throws Exception {
    ChannelPipeline pipeline = channel.pipeline();
    pipeline.addLast("idleStateHandler",
        new IdleStateHandler(idleTimeout, idleTimeout / 2, 0, TimeUnit.MILLISECONDS));

    if (hangDetection) {
      pipeline.addLast("MonitorClientHandler", new MonitorClientHandler());
    }
    pipeline.addLast("frameDecoder", new ProtobufVarint32FrameDecoder());
    pipeline.addLast("protobufDecoder", new ProtobufDecoder(defaultInstance));
    pipeline.addLast("frameEncoder", new ProtobufVarint32LengthFieldPrepender());
    pipeline.addLast("protobufEncoder", new ProtobufEncoder());
    pipeline.addLast("handler", handler);
  }
}