/*
    * Copyright 2012 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.channel;
  
  import io.netty.buffer.ByteBufAllocator;
  import io.netty.util.AbstractConstant;
  import io.netty.util.ConstantPool;
  import io.netty.util.internal.ObjectUtil;
  
  import java.net.InetAddress;
  import java.net.NetworkInterface;
  
  /**
   * A {@link ChannelOption} allows to configure a {@link ChannelConfig} in a type-safe
   * way. Which {@link ChannelOption} is supported depends on the actual implementation
   * of {@link ChannelConfig} and may depend on the nature of the transport it belongs
   * to.
   *
   * @param <T>   the type of the value which is valid for the {@link ChannelOption}
   */
  public class ChannelOption<T> extends AbstractConstant<ChannelOption<T>> {
  
      private static final ConstantPool<ChannelOption<Object>> pool = new ConstantPool<ChannelOption<Object>>() {
          @Override
          protected ChannelOption<Object> newConstant(int id, String name) {
              return new ChannelOption<Object>(id, name);
          }
      };
  
      /**
       * Returns the {@link ChannelOption} of the specified name.
       */
      @SuppressWarnings("unchecked")
      public static <T> ChannelOption<T> valueOf(String name) {
          return (ChannelOption<T>) pool.valueOf(name);
      }
  
      /**
       * Shortcut of {@link #valueOf(String) valueOf(firstNameComponent.getName() + "#" + secondNameComponent)}.
       */
      @SuppressWarnings("unchecked")
      public static <T> ChannelOption<T> valueOf(Class<?> firstNameComponent, String secondNameComponent) {
          return (ChannelOption<T>) pool.valueOf(firstNameComponent, secondNameComponent);
      }
  
      /**
       * Returns {@code true} if a {@link ChannelOption} exists for the given {@code name}.
       */
      public static boolean exists(String name) {
          return pool.exists(name);
      }
  
      /**
       * Creates a new {@link ChannelOption} for the given {@code name} or fail with an
       * {@link IllegalArgumentException} if a {@link ChannelOption} for the given {@code name} exists.
       *
       * @deprecated use {@link #valueOf(String)}.
       */
      @Deprecated
      @SuppressWarnings("unchecked")
      public static <T> ChannelOption<T> newInstance(String name) {
          return (ChannelOption<T>) pool.newInstance(name);
      }
  
      public static final ChannelOption<ByteBufAllocator> ALLOCATOR = valueOf("ALLOCATOR");
      public static final ChannelOption<RecvByteBufAllocator> RCVBUF_ALLOCATOR = valueOf("RCVBUF_ALLOCATOR");
      public static final ChannelOption<MessageSizeEstimator> MESSAGE_SIZE_ESTIMATOR = valueOf("MESSAGE_SIZE_ESTIMATOR");
  
      public static final ChannelOption<Integer> CONNECT_TIMEOUT_MILLIS = valueOf("CONNECT_TIMEOUT_MILLIS");
      /**
       * @deprecated Use {@link MaxMessagesRecvByteBufAllocator}
       * and {@link MaxMessagesRecvByteBufAllocator#maxMessagesPerRead(int)}.
       */
      @Deprecated
      public static final ChannelOption<Integer> MAX_MESSAGES_PER_READ = valueOf("MAX_MESSAGES_PER_READ");
      public static final ChannelOption<Integer> MAX_MESSAGES_PER_WRITE = valueOf("MAX_MESSAGES_PER_WRITE");
  
      public static final ChannelOption<Integer> WRITE_SPIN_COUNT = valueOf("WRITE_SPIN_COUNT");
      /**
       * @deprecated Use {@link #WRITE_BUFFER_WATER_MARK}
       */
      @Deprecated
      public static final ChannelOption<Integer> WRITE_BUFFER_HIGH_WATER_MARK = valueOf("WRITE_BUFFER_HIGH_WATER_MARK");
      /**
       * @deprecated Use {@link #WRITE_BUFFER_WATER_MARK}
       */
     @Deprecated
     public static final ChannelOption<Integer> WRITE_BUFFER_LOW_WATER_MARK = valueOf("WRITE_BUFFER_LOW_WATER_MARK");
     public static final ChannelOption<WriteBufferWaterMark> WRITE_BUFFER_WATER_MARK =
             valueOf("WRITE_BUFFER_WATER_MARK");
 
     public static final ChannelOption<Boolean> ALLOW_HALF_CLOSURE = valueOf("ALLOW_HALF_CLOSURE");
     public static final ChannelOption<Boolean> AUTO_READ = valueOf("AUTO_READ");
 
     /**
      * If {@code true} then the {@link Channel} is closed automatically and immediately on write failure.
      * The default value is {@code true}.
      */
     public static final ChannelOption<Boolean> AUTO_CLOSE = valueOf("AUTO_CLOSE");
 
     public static final ChannelOption<Boolean> SO_BROADCAST = valueOf("SO_BROADCAST");
     public static final ChannelOption<Boolean> SO_KEEPALIVE = valueOf("SO_KEEPALIVE");
     public static final ChannelOption<Integer> SO_SNDBUF = valueOf("SO_SNDBUF");
     public static final ChannelOption<Integer> SO_RCVBUF = valueOf("SO_RCVBUF");
     public static final ChannelOption<Boolean> SO_REUSEADDR = valueOf("SO_REUSEADDR");
     public static final ChannelOption<Integer> SO_LINGER = valueOf("SO_LINGER");
     public static final ChannelOption<Integer> SO_BACKLOG = valueOf("SO_BACKLOG");
     public static final ChannelOption<Integer> SO_TIMEOUT = valueOf("SO_TIMEOUT");
 
     public static final ChannelOption<Integer> IP_TOS = valueOf("IP_TOS");
     public static final ChannelOption<InetAddress> IP_MULTICAST_ADDR = valueOf("IP_MULTICAST_ADDR");
     public static final ChannelOption<NetworkInterface> IP_MULTICAST_IF = valueOf("IP_MULTICAST_IF");
     public static final ChannelOption<Integer> IP_MULTICAST_TTL = valueOf("IP_MULTICAST_TTL");
     public static final ChannelOption<Boolean> IP_MULTICAST_LOOP_DISABLED = valueOf("IP_MULTICAST_LOOP_DISABLED");
 
     public static final ChannelOption<Boolean> TCP_NODELAY = valueOf("TCP_NODELAY");
     /**
      * Client-side TCP FastOpen. Sending data with the initial TCP handshake.
      */
     public static final ChannelOption<Boolean> TCP_FASTOPEN_CONNECT = valueOf("TCP_FASTOPEN_CONNECT");
 
     /**
      * Server-side TCP FastOpen. Configures the maximum number of outstanding (waiting to be accepted) TFO connections.
      */
     public static final ChannelOption<Integer> TCP_FASTOPEN = valueOf(ChannelOption.class, "TCP_FASTOPEN");
 
     @Deprecated
     public static final ChannelOption<Boolean> DATAGRAM_CHANNEL_ACTIVE_ON_REGISTRATION =
             valueOf("DATAGRAM_CHANNEL_ACTIVE_ON_REGISTRATION");
 
     public static final ChannelOption<Boolean> SINGLE_EVENTEXECUTOR_PER_GROUP =
             valueOf("SINGLE_EVENTEXECUTOR_PER_GROUP");
 
     /**
      * Creates a new {@link ChannelOption} with the specified unique {@code name}.
      */
     private ChannelOption(int id, String name) {
         super(id, name);
     }
 
     @Deprecated
     protected ChannelOption(String name) {
         this(pool.nextId(), name);
     }
 
     /**
      * Validate the value which is set for the {@link ChannelOption}. Sub-classes
      * may override this for special checks.
      */
     public void validate(T value) {
         ObjectUtil.checkNotNull(value, "value");
     }
 }