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.Schema;
  import org.apache.calcite.schema.SchemaFactory;
  import org.apache.calcite.schema.SchemaPlus;
  
  import com.mongodb.AuthenticationMechanism;
  import com.mongodb.ConnectionString;
  import com.mongodb.MongoClientSettings;
  import com.mongodb.MongoCredential;
  
  import java.util.Map;
  
  /**
   * Factory that creates a {@link MongoSchema}.
   *
   * <p>Allows a custom schema to be included in a model.json file.
   */
  public class MongoSchemaFactory implements SchemaFactory {
    // public constructor, per factory contract
    public MongoSchemaFactory() {
    }
  
    @Override public Schema create(SchemaPlus parentSchema, String name,
        Map<String, Object> operand) {
      final String host = (String) operand.get("host");
      final String database = (String) operand.get("database");
      final String authMechanismName = (String) operand.get("authMechanism");
  
      final MongoClientSettings.Builder settings =
          MongoClientSettings
              .builder()
              .applyConnectionString(new ConnectionString(host));
  
      if (authMechanismName != null) {
        settings.credential(createCredential(operand));
      }
  
      return new MongoSchema(settings.build(), database);
    }
  
    private static MongoCredential createCredential(Map<String, Object> map) {
      final String authMechanismName = (String) map.get("authMechanism");
      final AuthenticationMechanism authenticationMechanism =
          AuthenticationMechanism.fromMechanismName(authMechanismName);
      final String username = (String) map.get("username");
      final String authDatabase = (String) map.get("authDatabase");
      final String password = (String) map.get("password");
  
      switch (authenticationMechanism) {
      case PLAIN:
        return MongoCredential.createPlainCredential(username, authDatabase,
            password.toCharArray());
      case SCRAM_SHA_1:
        return MongoCredential.createScramSha1Credential(username, authDatabase,
            password.toCharArray());
      case SCRAM_SHA_256:
        return MongoCredential.createScramSha256Credential(username, authDatabase,
            password.toCharArray());
      case GSSAPI:
        return MongoCredential.createGSSAPICredential(username);
      case MONGODB_X509:
        return MongoCredential.createMongoX509Credential(username);
      default:
        break;
      }
      throw new IllegalArgumentException("Unsupported authentication mechanism "
          + authMechanismName);
    }
  }
  