/*
    *  Licensed to the Apache Software Foundation (ASF) under one
    *  or more contributor license agreements.  See the NOTICE file
    *  distributed with this work for additional information
    *  regarding copyright ownership.  The ASF 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.apache.mina.core.session;
  
  import java.io.IOException;
  import java.net.SocketAddress;
  import java.util.List;
  import java.util.Set;
  import java.util.concurrent.Executor;
  
  import org.apache.mina.core.file.FileRegion;
  import org.apache.mina.core.filterchain.DefaultIoFilterChain;
  import org.apache.mina.core.filterchain.IoFilter;
  import org.apache.mina.core.filterchain.IoFilterChain;
  import org.apache.mina.core.future.IoFuture;
  import org.apache.mina.core.service.AbstractIoAcceptor;
  import org.apache.mina.core.service.DefaultTransportMetadata;
  import org.apache.mina.core.service.IoAcceptor;
  import org.apache.mina.core.service.IoHandler;
  import org.apache.mina.core.service.IoHandlerAdapter;
  import org.apache.mina.core.service.IoProcessor;
  import org.apache.mina.core.service.IoService;
  import org.apache.mina.core.service.TransportMetadata;
  import org.apache.mina.core.write.WriteRequest;
  
  /**
   * A dummy {@link IoSession} for unit-testing or non-network-use of
   * the classes that depends on {@link IoSession}.
   *
   * <h2>Overriding I/O request methods</h2>
   * All I/O request methods (i.e. {@link #close()}, {@link #write(Object)} and
   * {@link #setTrafficMask(TrafficMask)}) are final and therefore cannot be
   * overridden, but you can always add your custom {@link IoFilter} to the
   * {@link IoFilterChain} to intercept any I/O events and requests.
   *
   * @author The Apache MINA Project (dev@mina.apache.org)
   */
  public class DummySession extends AbstractIoSession {
  
      private static final TransportMetadata TRANSPORT_METADATA =
              new DefaultTransportMetadata(
                      "mina", "dummy", false, false,
                      SocketAddress.class, IoSessionConfig.class, Object.class);
  
      private static final SocketAddress ANONYMOUS_ADDRESS = new SocketAddress() {
          private static final long serialVersionUID = -496112902353454179L;
  
          @Override
          public String toString() {
              return "?";
          }
      };
  
      private volatile IoService service;
  
      private volatile IoSessionConfig config = new AbstractIoSessionConfig() {
          @Override
          protected void doSetAll(IoSessionConfig config) {
              // Do nothing
          }
      };
  
      private final IoFilterChain filterChain = new DefaultIoFilterChain(this);
      private final IoProcessor<AbstractIoSession> processor;
  
      private volatile IoHandler handler = new IoHandlerAdapter();
      private volatile SocketAddress localAddress = ANONYMOUS_ADDRESS;
      private volatile SocketAddress remoteAddress = ANONYMOUS_ADDRESS;
      private volatile TransportMetadata transportMetadata = TRANSPORT_METADATA;
  
      /**
       * Creates a new instance.
       */
      public DummySession() {
          // Initialize dummy service.
          IoAcceptor acceptor = new AbstractIoAcceptor(
                  new AbstractIoSessionConfig() {
                      @Override
                      protected void doSetAll(IoSessionConfig config) {
                          // Do nothing
                      }
                  },
                 new Executor() {
                     public void execute(Runnable command) {
                         // Do nothing
                     }
                 }) {
 
             @Override
             protected Set<SocketAddress> bindInternal(List<? extends SocketAddress> localAddresses) throws Exception {
                 throw new UnsupportedOperationException();
             }
 
             @Override
             protected void unbind0(List<? extends SocketAddress> localAddresses) throws Exception {
                 throw new UnsupportedOperationException();
             }
 
             public IoSession newSession(SocketAddress remoteAddress, SocketAddress localAddress) {
                 throw new UnsupportedOperationException();
             }
 
             public TransportMetadata getTransportMetadata() {
                 return TRANSPORT_METADATA;
             }
 
             @Override
             protected IoFuture dispose0() throws Exception {
                 return null;
             }
         };
 
         // Set meaningless default values.
         acceptor.setHandler(new IoHandlerAdapter());
 
         service = acceptor;
 
         processor = new IoProcessor<AbstractIoSession>() {
             public void add(AbstractIoSession session) {
                 // Do nothing
             }
 
             public void flush(AbstractIoSession session) {
                 DummySession s = (DummySession) session;
                 WriteRequest req = s.getWriteRequestQueue().poll(session);
                 
                 // Chek that the request is not null. If the session has been closed,
                 // we may not have any pending requests.
                 if (req != null) {
                     Object m = req.getMessage();
                     if (m instanceof FileRegion) {
                         FileRegion file = (FileRegion) m;
                         try {
                             file.getFileChannel().position(file.getPosition() + file.getRemainingBytes());
                             file.update(file.getRemainingBytes());
                         } catch (IOException e) {
                             s.getFilterChain().fireExceptionCaught(e);
                         }
                     }
                     getFilterChain().fireMessageSent(req);
                 }
             }
 
             public void remove(AbstractIoSession session) {
                 if (!session.getCloseFuture().isClosed()) {
                     session.getFilterChain().fireSessionClosed();
                 }
             }
 
             public void updateTrafficControl(AbstractIoSession session) {
                 // Do nothing
             }
 
             public void dispose() {
                 // Do nothing
             }
 
             public boolean isDisposed() {
                 return false;
             }
 
             public boolean isDisposing() {
                 return false;
             }
 
         };
 
         try {
             IoSessionDataStructureFactory factory = new DefaultIoSessionDataStructureFactory();
             setAttributeMap(factory.getAttributeMap(this));
             setWriteRequestQueue(factory.getWriteRequestQueue(this));
         } catch (Exception e) {
             throw new InternalError();
         }
     }
 
     public IoSessionConfig getConfig() {
         return config;
     }
 
     /**
      * Sets the configuration of this session.
      */
     public void setConfig(IoSessionConfig config) {
         if (config == null) {
             throw new NullPointerException("config");
         }
 
         this.config = config;
     }
 
     public IoFilterChain getFilterChain() {
         return filterChain;
     }
 
     public IoHandler getHandler() {
         return handler;
     }
 
     /**
      * Sets the {@link IoHandler} which handles this session.
      */
     public void setHandler(IoHandler handler) {
         if (handler == null) {
             throw new NullPointerException("handler");
         }
 
         this.handler = handler;
     }
 
     public SocketAddress getLocalAddress() {
         return localAddress;
     }
 
     public SocketAddress getRemoteAddress() {
         return remoteAddress;
     }
 
     /**
      * Sets the socket address of local machine which is associated with
      * this session.
      */
     public void setLocalAddress(SocketAddress localAddress) {
         if (localAddress == null) {
             throw new NullPointerException("localAddress");
         }
 
         this.localAddress = localAddress;
     }
 
     /**
      * Sets the socket address of remote peer.
      */
     public void setRemoteAddress(SocketAddress remoteAddress) {
         if (remoteAddress == null) {
             throw new NullPointerException("remoteAddress");
         }
 
         this.remoteAddress = remoteAddress;
     }
 
     public IoService getService() {
         return service;
     }
 
     /**
      * Sets the {@link IoService} which provides I/O service to this session.
      */
     public void setService(IoService service) {
         if (service == null) {
             throw new NullPointerException("service");
         }
 
         this.service = service;
     }
 
     @Override
     public final IoProcessor<AbstractIoSession> getProcessor() {
         return processor;
     }
 
     public TransportMetadata getTransportMetadata() {
         return transportMetadata;
     }
 
     /**
      * Sets the {@link TransportMetadata} that this session runs on.
      */
     public void setTransportMetadata(TransportMetadata transportMetadata) {
         if (transportMetadata == null) {
             throw new NullPointerException("transportMetadata");
         }
 
         this.transportMetadata = transportMetadata;
     }
 
     @Override
     public void setScheduledWriteBytes(int byteCount){
         super.setScheduledWriteBytes(byteCount);
     }
 
     @Override
     public void setScheduledWriteMessages(int messages) {
         super.setScheduledWriteMessages(messages);
     }
 
     /**
      * Update all statistical properties related with throughput.  By default
      * this method returns silently without updating the throughput properties
      * if they were calculated already within last
      * {@link IoSessionConfig#getThroughputCalculationInterval() calculation interval}.
      * If, however, <tt>force</tt> is specified as <tt>true</tt>, this method
      * updates the throughput properties immediately.
      */
     public void updateThroughput(boolean force) {
         super.updateThroughput(System.currentTimeMillis(), force);
     }
 }