/*
    * 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 io.netty.channel.socket.oio;
  
  import io.netty.channel.ChannelException;
  import io.netty.channel.ChannelMetadata;
  import io.netty.channel.ChannelOutboundBuffer;
  import io.netty.channel.oio.AbstractOioMessageChannel;
  import io.netty.channel.socket.ServerSocketChannel;
  import io.netty.util.internal.SocketUtils;
  import io.netty.util.internal.logging.InternalLogger;
  import io.netty.util.internal.logging.InternalLoggerFactory;
  
  import java.io.IOException;
  import java.net.InetSocketAddress;
  import java.net.ServerSocket;
  import java.net.Socket;
  import java.net.SocketAddress;
  import java.net.SocketTimeoutException;
  import java.util.List;
  import java.util.concurrent.locks.Lock;
  import java.util.concurrent.locks.ReentrantLock;
  
  /**
   * {@link ServerSocketChannel} which accepts new connections and create the {@link OioSocketChannel}'s for them.
   *
   * This implementation use Old-Blocking-IO.
   */
  public class OioServerSocketChannel extends AbstractOioMessageChannel
                                      implements ServerSocketChannel {
  
      private static final InternalLogger logger =
          InternalLoggerFactory.getInstance(OioServerSocketChannel.class);
  
      private static final ChannelMetadata METADATA = new ChannelMetadata(false);
  
      private static ServerSocket newServerSocket() {
          try {
              return new ServerSocket();
          } catch (IOException e) {
              throw new ChannelException("failed to create a server socket", e);
          }
      }
  
      final ServerSocket socket;
      final Lock shutdownLock = new ReentrantLock();
      private final OioServerSocketChannelConfig config;
  
      /**
       * Create a new instance with an new {@link Socket}
       */
      public OioServerSocketChannel() {
          this(newServerSocket());
      }
  
      /**
       * Create a new instance from the given {@link ServerSocket}
       *
       * @param socket    the {@link ServerSocket} which is used by this instance
       */
      public OioServerSocketChannel(ServerSocket socket) {
          super(null);
          if (socket == null) {
              throw new NullPointerException("socket");
          }
  
          boolean success = false;
          try {
              socket.setSoTimeout(SO_TIMEOUT);
              success = true;
          } catch (IOException e) {
              throw new ChannelException(
                      "Failed to set the server socket timeout.", e);
          } finally {
              if (!success) {
                  try {
                      socket.close();
                  } catch (IOException e) {
                      if (logger.isWarnEnabled()) {
                          logger.warn(
                                  "Failed to close a partially initialized socket.", e);
                      }
                  }
              }
          }
          this.socket = socket;
         config = new DefaultOioServerSocketChannelConfig(this, socket);
     }
 
     @Override
     public InetSocketAddress localAddress() {
         return (InetSocketAddress) super.localAddress();
     }
 
     @Override
     public ChannelMetadata metadata() {
         return METADATA;
     }
 
     @Override
     public OioServerSocketChannelConfig config() {
         return config;
     }
 
     @Override
     public InetSocketAddress remoteAddress() {
         return null;
     }
 
     @Override
     public boolean isOpen() {
         return !socket.isClosed();
     }
 
     @Override
     public boolean isActive() {
         return isOpen() && socket.isBound();
     }
 
     @Override
     protected SocketAddress localAddress0() {
         return SocketUtils.localSocketAddress(socket);
     }
 
     @Override
     protected void doBind(SocketAddress localAddress) throws Exception {
         socket.bind(localAddress, config.getBacklog());
     }
 
     @Override
     protected void doClose() throws Exception {
         socket.close();
     }
 
     @Override
     protected int doReadMessages(List<Object> buf) throws Exception {
         if (socket.isClosed()) {
             return -1;
         }
 
         try {
             Socket s = socket.accept();
             try {
                 buf.add(new OioSocketChannel(this, s));
                 return 1;
             } catch (Throwable t) {
                 logger.warn("Failed to create a new channel from an accepted socket.", t);
                 try {
                     s.close();
                 } catch (Throwable t2) {
                     logger.warn("Failed to close a socket.", t2);
                 }
             }
         } catch (SocketTimeoutException e) {
             // Expected
         }
         return 0;
     }
 
     @Override
     protected void doWrite(ChannelOutboundBuffer in) throws Exception {
         throw new UnsupportedOperationException();
     }
 
     @Override
     protected Object filterOutboundMessage(Object msg) throws Exception {
         throw new UnsupportedOperationException();
     }
 
     @Override
     protected void doConnect(
             SocketAddress remoteAddress, SocketAddress localAddress) throws Exception {
         throw new UnsupportedOperationException();
     }
 
     @Override
     protected SocketAddress remoteAddress0() {
         return null;
     }
 
     @Override
     protected void doDisconnect() throws Exception {
         throw new UnsupportedOperationException();
     }
 
     @Override
     protected void setReadPending(boolean readPending) {
         super.setReadPending(readPending);
     }
 }