/*
    * Copyright 2015 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:
    *
    *   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 io.netty.channel.epoll;
  
  import io.netty.buffer.ByteBufAllocator;
  import io.netty.channel.ChannelException;
  import io.netty.channel.ChannelOption;
  import io.netty.channel.DefaultChannelConfig;
  import io.netty.channel.MessageSizeEstimator;
  import io.netty.channel.RecvByteBufAllocator;
  import io.netty.channel.WriteBufferWaterMark;
  
  import java.io.IOException;
  import java.util.Map;
  
  import static io.netty.channel.unix.Limits.SSIZE_MAX;
  
  public class EpollChannelConfig extends DefaultChannelConfig {
      private volatile long maxBytesPerGatheringWrite = SSIZE_MAX;
  
      EpollChannelConfig(AbstractEpollChannel channel) {
          super(channel);
      }
  
      @Override
      public Map<ChannelOption<?>, Object> getOptions() {
          return getOptions(super.getOptions(), EpollChannelOption.EPOLL_MODE);
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public <T> T getOption(ChannelOption<T> option) {
          if (option == EpollChannelOption.EPOLL_MODE) {
              return (T) getEpollMode();
          }
          return super.getOption(option);
      }
  
      @Override
      public <T> boolean setOption(ChannelOption<T> option, T value) {
          validate(option, value);
          if (option == EpollChannelOption.EPOLL_MODE) {
              setEpollMode((EpollMode) value);
          } else {
              return super.setOption(option, value);
          }
          return true;
      }
  
      @Override
      public EpollChannelConfig setConnectTimeoutMillis(int connectTimeoutMillis) {
          super.setConnectTimeoutMillis(connectTimeoutMillis);
          return this;
      }
  
      @Override
      @Deprecated
      public EpollChannelConfig setMaxMessagesPerRead(int maxMessagesPerRead) {
          super.setMaxMessagesPerRead(maxMessagesPerRead);
          return this;
      }
  
      @Override
      public EpollChannelConfig setWriteSpinCount(int writeSpinCount) {
          super.setWriteSpinCount(writeSpinCount);
          return this;
      }
  
      @Override
      public EpollChannelConfig setAllocator(ByteBufAllocator allocator) {
          super.setAllocator(allocator);
          return this;
      }
  
      @Override
      public EpollChannelConfig setRecvByteBufAllocator(RecvByteBufAllocator allocator) {
          if (!(allocator.newHandle() instanceof RecvByteBufAllocator.ExtendedHandle)) {
              throw new IllegalArgumentException("allocator.newHandle() must return an object of type: " +
                      RecvByteBufAllocator.ExtendedHandle.class);
          }
          super.setRecvByteBufAllocator(allocator);
          return this;
      }
  
      @Override
      public EpollChannelConfig setAutoRead(boolean autoRead) {
         super.setAutoRead(autoRead);
         return this;
     }
 
     @Override
     @Deprecated
     public EpollChannelConfig setWriteBufferHighWaterMark(int writeBufferHighWaterMark) {
         super.setWriteBufferHighWaterMark(writeBufferHighWaterMark);
         return this;
     }
 
     @Override
     @Deprecated
     public EpollChannelConfig setWriteBufferLowWaterMark(int writeBufferLowWaterMark) {
         super.setWriteBufferLowWaterMark(writeBufferLowWaterMark);
         return this;
     }
 
     @Override
     public EpollChannelConfig setWriteBufferWaterMark(WriteBufferWaterMark writeBufferWaterMark) {
         super.setWriteBufferWaterMark(writeBufferWaterMark);
         return this;
     }
 
     @Override
     public EpollChannelConfig setMessageSizeEstimator(MessageSizeEstimator estimator) {
         super.setMessageSizeEstimator(estimator);
         return this;
     }
 
     /**
      * Return the {@link EpollMode} used. Default is
      * {@link EpollMode#EDGE_TRIGGERED}. If you want to use {@link #isAutoRead()} {@code false} or
      * {@link #getMaxMessagesPerRead()} and have an accurate behaviour you should use
      * {@link EpollMode#LEVEL_TRIGGERED}.
      */
     public EpollMode getEpollMode() {
         return ((AbstractEpollChannel) channel).isFlagSet(Native.EPOLLET)
                 ? EpollMode.EDGE_TRIGGERED : EpollMode.LEVEL_TRIGGERED;
     }
 
     /**
      * Set the {@link EpollMode} used. Default is
      * {@link EpollMode#EDGE_TRIGGERED}. If you want to use {@link #isAutoRead()} {@code false} or
      * {@link #getMaxMessagesPerRead()} and have an accurate behaviour you should use
      * {@link EpollMode#LEVEL_TRIGGERED}.
      *
      * <strong>Be aware this config setting can only be adjusted before the channel was registered.</strong>
      */
     public EpollChannelConfig setEpollMode(EpollMode mode) {
         if (mode == null) {
             throw new NullPointerException("mode");
         }
         try {
             switch (mode) {
             case EDGE_TRIGGERED:
                 checkChannelNotRegistered();
                 ((AbstractEpollChannel) channel).setFlag(Native.EPOLLET);
                 break;
             case LEVEL_TRIGGERED:
                 checkChannelNotRegistered();
                 ((AbstractEpollChannel) channel).clearFlag(Native.EPOLLET);
                 break;
             default:
                 throw new Error();
             }
         } catch (IOException e) {
             throw new ChannelException(e);
         }
         return this;
     }
 
     private void checkChannelNotRegistered() {
         if (channel.isRegistered()) {
             throw new IllegalStateException("EpollMode can only be changed before channel is registered");
         }
     }
 
     @Override
     protected final void autoReadCleared() {
         ((AbstractEpollChannel) channel).clearEpollIn();
     }
 
     final void setMaxBytesPerGatheringWrite(long maxBytesPerGatheringWrite) {
         this.maxBytesPerGatheringWrite = maxBytesPerGatheringWrite;
     }
 
     final long getMaxBytesPerGatheringWrite() {
         return maxBytesPerGatheringWrite;
     }
 }