/*

  * #%L

  * AbstractProxyConnection.java - mongodb-async-driver - Allanbank Consulting, Inc.

  * %%

  * Copyright (C) 2011 - 2014 Allanbank Consulting, Inc.

  * %%

  * Licensed 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.

  * #L%

  */

 package com.allanbank.mongodb.client.connection.proxy;

 import java.beans.PropertyChangeEvent;

 import java.beans.PropertyChangeListener;

 import java.io.IOException;

 import java.util.concurrent.TimeUnit;

 import com.allanbank.mongodb.MongoDbException;

 import com.allanbank.mongodb.client.Message;

 import com.allanbank.mongodb.client.callback.ReplyCallback;

 import com.allanbank.mongodb.client.connection.Connection;

 import com.allanbank.mongodb.util.IOUtils;

 /**

  * A helper class for constructing connections that are really just proxies on

  * top of other connections.

  * 

  * @api.no This class is <b>NOT</b> part of the drivers API. This class may be

  *         mutated in incompatible ways between any two releases of the driver.

  * @copyright 2011-2014, Allanbank Consulting, Inc., All Rights Reserved

  */

 public abstract class AbstractProxyConnection implements Connection {

     /** The proxied connection. */

     private final Connection myProxiedConnection;

     /**

      * Creates a AbstractProxyConnection.

      * 

      * @param proxiedConnection

      *            The connection to forward to.

      */

     public AbstractProxyConnection(final Connection proxiedConnection) {

         myProxiedConnection = proxiedConnection;

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to create a proxy connection if not already created and add

      * the listener to that connection.

      * </p>

      */

     @Override

     public void addPropertyChangeListener(final PropertyChangeListener listener) {

         try {

             myProxiedConnection

                     .addPropertyChangeListener(new ProxiedChangeListener(this,

                             listener));

         }

         catch (final MongoDbException error) {

             onExceptin(error);

             listener.propertyChange(new PropertyChangeEvent(this,

                     OPEN_PROP_NAME, Boolean.TRUE, Boolean.FALSE));

         }

     }

     /**

      * Closes the underlying connection.

      * 

      * @see Connection#close()

      */

     @Override

     public void close() throws IOException {

         myProxiedConnection.close();

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      * 

      * @see java.io.Flushable#flush()

      */

     @Override

     public void flush() throws IOException {

         try {

             myProxiedConnection.flush();

         }

         catch (final MongoDbException error) {

             onExceptin(error);

             throw error;

         }

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      */

     @Override

     public int getPendingCount() {

         try {

             return myProxiedConnection.getPendingCount();

         }

         catch (final MongoDbException error) {

             onExceptin(error);

             throw error;

         }

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to forward the call to the proxied connection.

      * </p>

      */

     @Override

     public String getServerName() {

         return getProxiedConnection().getServerName();

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      */

     @Override

     public boolean isAvailable() {

         try {

             return myProxiedConnection.isAvailable();

         }

         catch (final MongoDbException error) {

             onExceptin(error);

             throw error;

         }

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      */

     @Override

     public boolean isIdle() {

         try {

             return myProxiedConnection.isIdle();

         }

         catch (final MongoDbException error) {

             onExceptin(error);

             throw error;

         }

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      */

     @Override

     public boolean isOpen() {

         try {

             return myProxiedConnection.isOpen();

         }

         catch (final MongoDbException error) {

             onExceptin(error);

             throw error;

         }

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      */

     @Override

     public boolean isShuttingDown() {

         return myProxiedConnection.isShuttingDown();

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      */

     @Override

     public void raiseErrors(final MongoDbException exception) {

         myProxiedConnection.raiseErrors(exception);

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to create a proxy connection if not already created and add

      * the listener to that connection.

      * </p>

      */

     @Override

     public void removePropertyChangeListener(

             final PropertyChangeListener listener) {

         myProxiedConnection

                 .removePropertyChangeListener(new ProxiedChangeListener(this,

                         listener));

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      */

     @Override

     public void send(final Message message1, final Message message2,

             final ReplyCallback replyCallback) throws MongoDbException {

         try {

             myProxiedConnection.send(message1, message2, replyCallback);

         }

         catch (final MongoDbException error) {

             onExceptin(error);

             throw error;

         }

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      */

     @Override

     public void send(final Message message, final ReplyCallback replyCallback)

             throws MongoDbException {

         try {

             myProxiedConnection.send(message, replyCallback);

         }

         catch (final MongoDbException error) {

             onExceptin(error);

             throw error;

         }

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      */

     @Override

     public void shutdown(final boolean force) {

         myProxiedConnection.shutdown(force);

     }

     /**

      * {@inheritDoc}

      * <p>

      * Forwards the call to the proxied {@link Connection}.

      * </p>

      */

     @Override

     public void waitForClosed(final int timeout, final TimeUnit timeoutUnits) {

         try {

             myProxiedConnection.waitForClosed(timeout, timeoutUnits);

         }

         catch (final MongoDbException error) {

             onExceptin(error);

             throw error;

         }

     }

     /**

      * Returns the proxiedConnection value.

      * 

      * @return The proxiedConnection value.

      */

     protected Connection getProxiedConnection() {

         return myProxiedConnection;

     }

     /**

      * Provides the ability for derived classes to intercept any exceptions from

      * the underlying proxied connection.

      * <p>

      * Closes the underlying connection.

      * </p>

      * 

      * @param exception

      *            The thrown exception.

      */

     protected void onExceptin(final MongoDbException exception) {

         // Close without fear of an exception.

         IOUtils.close(this);

     }

     /**

      * ProxiedChangeListener provides a change listener to modify the source of

      * the event to the outer connection from the (inner) proxied connection.

      * 

      * @copyright 2012-2013, Allanbank Consulting, Inc., All Rights Reserved

      */

     protected static class ProxiedChangeListener implements

             PropertyChangeListener {

         /** The delegate listener. */

         private final PropertyChangeListener myDelegate;

         /** The proxied connection. */

         private final AbstractProxyConnection myProxiedConn;

         /**

          * Creates a new ProxiedChangeListener.

          * 

          * @param proxiedConn

          *            The proxied connection.

          * @param delegate

          *            The delegate listener.

          */

         public ProxiedChangeListener(final AbstractProxyConnection proxiedConn,

                 final PropertyChangeListener delegate) {

             myProxiedConn = proxiedConn;

             myDelegate = delegate;

         }

         /**

          * {@inheritDoc}

          * <p>

          * Overridden to compare the nested delegate listeners.

          * </p>

          */

         @Override

         public boolean equals(final Object object) {

             boolean result = false;

             if (this == object) {

                 result = true;

             }

             else if ((object != null) && (getClass() == object.getClass())) {

                 final ProxiedChangeListener other = (ProxiedChangeListener) object;

                 result = myDelegate.equals(other.myDelegate);

             }

             return result;

         }

         /**

          * {@inheritDoc}

          * <p>

          * Overridden to return the delegates hash code.

          * </p>

          */

         @Override

         public int hashCode() {

             return ((myDelegate == null) ? 13 : myDelegate.hashCode());

         }

         /**

          * {@inheritDoc}

          * <p>

          * Overridden to change the source of the property change event to the

          * outer connection instead of the inner connection.

          * </p>

          */

         @Override

         public void propertyChange(final PropertyChangeEvent event) {

             final PropertyChangeEvent newEvent = new PropertyChangeEvent(

                     myProxiedConn, event.getPropertyName(),

                     event.getOldValue(), event.getNewValue());

             newEvent.setPropagationId(event.getPropagationId());

             myDelegate.propertyChange(newEvent);

         }

     }

 }