/*
    * 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.logging.log4j.nosql.appender.mongodb;
  
  import org.apache.logging.log4j.Level;
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.core.appender.AppenderLoggingException;
  import org.apache.logging.log4j.nosql.appender.AbstractNoSqlConnection;
  import org.apache.logging.log4j.nosql.appender.NoSqlConnection;
  import org.apache.logging.log4j.nosql.appender.NoSqlObject;
  import org.apache.logging.log4j.status.StatusLogger;
  import org.bson.BSON;
  import org.bson.Transformer;
  
  import com.mongodb.BasicDBObject;
  import com.mongodb.DB;
  import com.mongodb.DBCollection;
  import com.mongodb.MongoException;
  import com.mongodb.WriteConcern;
  
  /**
   * The MongoDB implementation of {@link NoSqlConnection}.
   */
  public final class MongoDbConnection extends AbstractNoSqlConnection<BasicDBObject, MongoDbObject> {
  
      private static final Logger LOGGER = StatusLogger.getLogger();
  
      static {
          BSON.addEncodingHook(Level.class, new Transformer() {
              @Override
              public Object transform(final Object o) {
                  if (o instanceof Level) {
                      return ((Level) o).name();
                  }
                  return o;
              }
          });
      }
  
      private final DBCollection collection;
      private final WriteConcern writeConcern;
  
      public MongoDbConnection(final DB database, final WriteConcern writeConcern, final String collectionName) {
          this.collection = database.getCollection(collectionName);
          this.writeConcern = writeConcern;
      }
  
      @Override
      public MongoDbObject createObject() {
          return new MongoDbObject();
      }
  
      @Override
      public MongoDbObject[] createList(final int length) {
          return new MongoDbObject[length];
      }
  
      @Override
      public void insertObject(final NoSqlObject<BasicDBObject> object) {
          try {
              this.collection.insert(object.unwrap(), this.writeConcern);
          } catch (final MongoException e) {
              throw new AppenderLoggingException("Failed to write log event to MongoDB due to error: " + e.getMessage(),
                      e);
          }
      }
  
      @Override
      public void closeImpl() {
          // there's no need to call this.mongo.close() since that literally closes the connection.
          // MongoDBClient uses internal connection pooling.
          // For more details, see LOG4J2-591.
      }
  
  }