/*

  * #%L

  * ReplicaSetConnection.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.rs;

 import java.io.IOException;

 import java.util.List;

 import com.allanbank.mongodb.MongoClientConfiguration;

 import com.allanbank.mongodb.MongoDbException;

 import com.allanbank.mongodb.client.Message;

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

 import com.allanbank.mongodb.client.connection.proxy.AbstractProxyMultipleConnection;

 import com.allanbank.mongodb.client.connection.proxy.ConnectionInfo;

 import com.allanbank.mongodb.client.connection.proxy.ProxiedConnectionFactory;

 import com.allanbank.mongodb.client.state.Cluster;

 import com.allanbank.mongodb.client.state.Server;

 import com.allanbank.mongodb.util.log.Log;

 import com.allanbank.mongodb.util.log.LogFactory;

 /**

  * Provides a {@link Connection} implementation for connecting to a replica-set

  * environment.

  * 

  * @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 2011-2013, Allanbank Consulting, Inc., All Rights Reserved

  */

 public class ReplicaSetConnection extends

         AbstractProxyMultipleConnection<Server> {

     /** The logger for the {@link ReplicaSetConnection}. */

     private static final Log LOG = LogFactory

             .getLog(ReplicaSetConnection.class);

     /** The strategy for reconnecting/finding the primary. */

     private volatile ReplicaSetReconnectStrategy myReconnectStrategy;

     /**

      * Creates a new {@link ReplicaSetConnection}.

      * 

      * @param proxiedConnection

      *            The connection being proxied.

      * @param server

      *            The primary server this connection is connected to.

      * @param cluster

      *            The state of the cluster for finding secondary connections.

      * @param factory

      *            The connection factory for opening secondary connections.

      * @param config

      *            The MongoDB client configuration.

      * @param strategy

      *            The strategy for reconnecting/finding the primary.

      */

     public ReplicaSetConnection(final Connection proxiedConnection,

             final Server server, final Cluster cluster,

             final ProxiedConnectionFactory factory,

             final MongoClientConfiguration config,

             final ReplicaSetReconnectStrategy strategy) {

         super(proxiedConnection, server, cluster, factory, config);

         myReconnectStrategy = strategy;

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to return the canonical name of the primary.

      * </p>

      */

     @Override

     public String getServerName() {

         if (myMainKey != null) {

             return myMainKey.getCanonicalName();

         }

         return "UNKNOWN";

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to create a connection to the server.

      * </p>

      */

     @Override

     protected Connection connect(final Server server) {

         Connection conn = null;

         try {

             conn = myFactory.connect(server, myConfig);

             conn = cacheConnection(server, conn);

         }

         catch (final IOException e) {

             LOG.info("Could not connect to the server '"

                     + server.getCanonicalName() + "': " + e.getMessage());

         }

         return conn;

     }

     /**

      * Locates the set of servers that can be used to send the specified

      * messages. This method will attempt to connect to the primary server if

      * there is not a current connection to the primary.

      * 

      * @param message1

      *            The first message to send.

      * @param message2

      *            The second message to send. May be <code>null</code>.

      * @return The servers that can be used.

      * @throws MongoDbException

      *             On a failure to locate a server that all messages can be sent

      *             to.

      */

     @Override

     protected List<Server> findPotentialKeys(final Message message1,

             final Message message2) throws MongoDbException {

         List<Server> servers = myCluster.findServers(message1, message2);

         if (servers.isEmpty()) {

             // If we get here and a reconnect is in progress then

             // block for the reconnect. The primary will have been marked a

             // secondary... Once the reconnect is complete, try again.

             if (myMainKey == null) {

                 // Wait for a reconnect.

                 final ConnectionInfo<Server> newConnInfo = reconnectMain();

                 if (newConnInfo != null) {

                     updateMain(newConnInfo);

                     servers = myCluster.findServers(message1, message2);

                 }

             }

             if (servers.isEmpty()) {

                 throw createReconnectFailure(message1, message2);

             }

         }

         return servers;

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to return the string {@code ReplicaSet}.

      * </p>

      */

     @Override

     protected String getConnectionType() {

         return "ReplicaSet";

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden creates a connection back to the primary server.

      * </p>

      */

     @Override

     protected ConnectionInfo<Server> reconnectMain() {

         return myReconnectStrategy.reconnectPrimary();

     }

 }