/*
    * Copyright 2022 The Netty Project
    *
    * The Netty Project 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:
    *
    *   https://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 io.netty.handler.ssl.ocsp;
  
  import io.netty.channel.ChannelFactory;
  import io.netty.channel.EventLoop;
  import io.netty.channel.nio.NioEventLoop;
  import io.netty.channel.nio.NioEventLoopGroup;
  import io.netty.channel.socket.DatagramChannel;
  import io.netty.channel.socket.SocketChannel;
  import io.netty.channel.socket.nio.NioDatagramChannel;
  import io.netty.channel.socket.nio.NioSocketChannel;
  
  import static io.netty.util.internal.ObjectUtil.checkNotNull;
  
  /**
   * {@link IoTransport} holds {@link EventLoop}, {@link SocketChannel}
   * and {@link DatagramChannel} for DNS I/O.
   */
  public final class IoTransport {
      private final EventLoop eventLoop;
      private final ChannelFactory<SocketChannel> socketChannel;
      private final ChannelFactory<DatagramChannel> datagramChannel;
  
      /**
       * Default {@link IoTransport} which uses {@link NioEventLoop}, {@link NioSocketChannel}
       * and {@link NioDatagramChannel}.
       */
      public static final IoTransport DEFAULT = new IoTransport(new NioEventLoopGroup(1).next(),
              new ChannelFactory<SocketChannel>() {
                  @Override
                  public SocketChannel newChannel() {
                      return new NioSocketChannel();
                  }
              },
              new ChannelFactory<DatagramChannel>() {
                  @Override
                  public DatagramChannel newChannel() {
                      return new NioDatagramChannel();
                  }
              });
  
      /**
       * Create a new {@link IoTransport} instance
       *
       * @param eventLoop       {@link EventLoop} to use for I/O
       * @param socketChannel   {@link SocketChannel} for TCP DNS lookup and OCSP query
       * @param datagramChannel {@link DatagramChannel} for UDP DNS lookup
       * @return {@link NullPointerException} if any parameter is {@code null}
       */
      public static IoTransport create(EventLoop eventLoop, ChannelFactory<SocketChannel> socketChannel,
                                       ChannelFactory<DatagramChannel> datagramChannel) {
          return new IoTransport(eventLoop, socketChannel, datagramChannel);
      }
  
      private IoTransport(EventLoop eventLoop, ChannelFactory<SocketChannel> socketChannel,
                          ChannelFactory<DatagramChannel> datagramChannel) {
          this.eventLoop = checkNotNull(eventLoop, "EventLoop");
          this.socketChannel = checkNotNull(socketChannel, "SocketChannel");
          this.datagramChannel = checkNotNull(datagramChannel, "DatagramChannel");
      }
  
      public EventLoop eventLoop() {
          return eventLoop;
      }
  
      public ChannelFactory<SocketChannel> socketChannel() {
          return socketChannel;
      }
  
      public ChannelFactory<DatagramChannel> datagramChannel() {
          return datagramChannel;
      }
  }