/*
    * 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:
    *
    *   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.jboss.netty.channel.socket.nio;
  
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.NetworkInterface;
  import java.net.SocketException;
  import java.net.StandardSocketOptions;
  import java.nio.channels.DatagramChannel;
  import java.util.Enumeration;
  import java.util.Map;
  
  import org.jboss.netty.channel.ChannelException;
  import org.jboss.netty.channel.socket.DefaultDatagramChannelConfig;
  import org.jboss.netty.logging.InternalLogger;
  import org.jboss.netty.logging.InternalLoggerFactory;
  import org.jboss.netty.util.internal.ConversionUtil;
  import org.jboss.netty.util.internal.DetectionUtil;
  
  /**
   * The default {@link NioSocketChannelConfig} implementation.
   */
  class DefaultNioDatagramChannelConfig extends DefaultDatagramChannelConfig
          implements NioDatagramChannelConfig {
  
      private static final InternalLogger logger =
              InternalLoggerFactory
                      .getInstance(DefaultNioDatagramChannelConfig.class);
  
      private volatile int writeBufferHighWaterMark = 64 * 1024;
      private volatile int writeBufferLowWaterMark = 32 * 1024;
      private volatile int writeSpinCount = 16;
      private final DatagramChannel channel;
  
      DefaultNioDatagramChannelConfig(DatagramChannel channel) {
          super(channel.socket());
          this.channel = channel;
      }
  
      @Override
      public void setOptions(Map<String, Object> options) {
          super.setOptions(options);
          if (getWriteBufferHighWaterMark() < getWriteBufferLowWaterMark()) {
              // Recover the integrity of the configuration with a sensible value.
              setWriteBufferLowWaterMark0(getWriteBufferHighWaterMark() >>> 1);
              if (logger.isWarnEnabled()) {
                  // Notify the user about misconfiguration.
                  logger.warn("writeBufferLowWaterMark cannot be greater than "
                          + "writeBufferHighWaterMark; setting to the half of the "
                          + "writeBufferHighWaterMark.");
              }
          }
      }
  
      @Override
      public boolean setOption(String key, Object value) {
          if (super.setOption(key, value)) {
              return true;
          }
  
          if ("writeBufferHighWaterMark".equals(key)) {
              setWriteBufferHighWaterMark0(ConversionUtil.toInt(value));
          } else if ("writeBufferLowWaterMark".equals(key)) {
              setWriteBufferLowWaterMark0(ConversionUtil.toInt(value));
          } else if ("writeSpinCount".equals(key)) {
              setWriteSpinCount(ConversionUtil.toInt(value));
          } else {
              return false;
          }
          return true;
      }
  
      public int getWriteBufferHighWaterMark() {
          return writeBufferHighWaterMark;
      }
  
      public void setWriteBufferHighWaterMark(int writeBufferHighWaterMark) {
          if (writeBufferHighWaterMark < getWriteBufferLowWaterMark()) {
              throw new IllegalArgumentException(
                      "writeBufferHighWaterMark cannot be less than " +
                              "writeBufferLowWaterMark (" +
                              getWriteBufferLowWaterMark() + "): " +
                              writeBufferHighWaterMark);
          }
          setWriteBufferHighWaterMark0(writeBufferHighWaterMark);
     }
 
     private void setWriteBufferHighWaterMark0(int writeBufferHighWaterMark) {
         if (writeBufferHighWaterMark < 0) {
             throw new IllegalArgumentException("writeBufferHighWaterMark: " +
                     writeBufferHighWaterMark);
         }
         this.writeBufferHighWaterMark = writeBufferHighWaterMark;
     }
 
     public int getWriteBufferLowWaterMark() {
         return writeBufferLowWaterMark;
     }
 
     public void setWriteBufferLowWaterMark(int writeBufferLowWaterMark) {
         if (writeBufferLowWaterMark > getWriteBufferHighWaterMark()) {
             throw new IllegalArgumentException(
                     "writeBufferLowWaterMark cannot be greater than " +
                             "writeBufferHighWaterMark (" +
                             getWriteBufferHighWaterMark() + "): " +
                             writeBufferLowWaterMark);
         }
         setWriteBufferLowWaterMark0(writeBufferLowWaterMark);
     }
 
     private void setWriteBufferLowWaterMark0(int writeBufferLowWaterMark) {
         if (writeBufferLowWaterMark < 0) {
             throw new IllegalArgumentException("writeBufferLowWaterMark: " +
                     writeBufferLowWaterMark);
         }
         this.writeBufferLowWaterMark = writeBufferLowWaterMark;
     }
 
     public int getWriteSpinCount() {
         return writeSpinCount;
     }
 
     public void setWriteSpinCount(int writeSpinCount) {
         if (writeSpinCount <= 0) {
             throw new IllegalArgumentException(
                     "writeSpinCount must be a positive integer.");
         }
         this.writeSpinCount = writeSpinCount;
     }
 
     @Override
     public void setNetworkInterface(NetworkInterface networkInterface) {
         if (DetectionUtil.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         } else {
             try {
                 channel.setOption(StandardSocketOptions.IP_MULTICAST_IF, networkInterface);
             } catch (IOException e) {
                 throw new ChannelException(e);
             }
         }
     }
 
     @Override
     public NetworkInterface getNetworkInterface() {
         if (DetectionUtil.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         } else {
             try {
                 return channel.getOption(StandardSocketOptions.IP_MULTICAST_IF);
             } catch (IOException e) {
                 throw new ChannelException(e);
             }
         }
     }
 
     @Override
     public int getTimeToLive() {
         if (DetectionUtil.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         } else {
             try {
                 return channel.getOption(StandardSocketOptions.IP_MULTICAST_TTL);
             } catch (IOException e) {
                 throw new ChannelException(e);
             }
         }
     }
 
     @Override
     public void setTimeToLive(int ttl) {
         if (DetectionUtil.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         } else {
             try {
                 channel.setOption(StandardSocketOptions.IP_MULTICAST_TTL, ttl);
             } catch (IOException e) {
                 throw new ChannelException(e);
             }
         }
     }
 
     @Override
     public InetAddress getInterface() {
         NetworkInterface inf = getNetworkInterface();
         if (inf == null) {
             return null;
         } else {
             Enumeration<InetAddress> addresses = inf.getInetAddresses();
             if (addresses.hasMoreElements()) {
                 return addresses.nextElement();
             }
             return null;
         }
     }
 
     @Override
     public void setInterface(InetAddress interfaceAddress) {
         try {
             setNetworkInterface(NetworkInterface.getByInetAddress(interfaceAddress));
         } catch (SocketException e) {
             throw new ChannelException(e);
         }
     }
 
     @Override
     public boolean isLoopbackModeDisabled() {
         if (DetectionUtil.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         } else {
             try {
                 return channel.getOption(StandardSocketOptions.IP_MULTICAST_LOOP);
             } catch (IOException e) {
                 throw new ChannelException(e);
             }
         }
     }
 
     @Override
     public void setLoopbackModeDisabled(boolean loopbackModeDisabled) {
         if (DetectionUtil.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         } else {
             try {
                 channel.setOption(StandardSocketOptions.IP_MULTICAST_LOOP, loopbackModeDisabled);
             } catch (IOException e) {
                 throw new ChannelException(e);
             }
         }
     }
 }