content: /*
   * 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.calcite.adapter.mongodb;
  
  import org.apache.calcite.schema.Table;
  import org.apache.calcite.schema.impl.AbstractSchema;
  
  import com.google.common.annotations.VisibleForTesting;
  import com.google.common.collect.ImmutableMap;
  import com.mongodb.MongoClientSettings;
  import com.mongodb.client.MongoClient;
  import com.mongodb.client.MongoClients;
  import com.mongodb.client.MongoDatabase;
  
  import java.util.Map;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Schema mapped onto a directory of MONGO files. Each table in the schema
   * is a MONGO file in that directory.
   */
  public class MongoSchema extends AbstractSchema {
    final MongoDatabase mongoDb;
  
    /**
     * Creates a MongoDB schema.
     *
     * @param settings Mongo connection settings, including host and credentials
     * @param database Mongo database name, e.g. "foodmart"
     */
    MongoSchema(MongoClientSettings settings, String database) {
      super();
  
      final MongoClient mongo = MongoClients.create(settings);
      try {
        this.mongoDb = mongo.getDatabase(database);
      } catch (Exception e) {
        mongo.close();
        throw new RuntimeException(e);
      }
    }
  
    /**
     * Allows tests to inject their instance of the database.
     *
     * @param mongoDb existing mongo database instance
     */
    @VisibleForTesting
    MongoSchema(MongoDatabase mongoDb) {
      super();
      this.mongoDb = requireNonNull(mongoDb, "mongoDb");
    }
  
    @Override protected Map<String, Table> getTableMap() {
      final ImmutableMap.Builder<String, Table> builder = ImmutableMap.builder();
      for (String collectionName : mongoDb.listCollectionNames()) {
        builder.put(collectionName, new MongoTable(collectionName));
      }
      return builder.build();
    }
  }
  