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.cassandra;
  
  import org.apache.calcite.schema.Schema;
  import org.apache.calcite.schema.SchemaFactory;
  import org.apache.calcite.schema.SchemaPlus;
  import org.apache.calcite.util.trace.CalciteTrace;
  
  import com.datastax.oss.driver.api.core.CqlIdentifier;
  import com.datastax.oss.driver.api.core.CqlSession;
  import com.datastax.oss.driver.api.core.CqlSessionBuilder;
  import com.google.common.collect.ImmutableSet;
  
  import org.slf4j.Logger;
  
  import java.net.InetSocketAddress;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.stream.Collectors;
  
  import static java.lang.Integer.parseInt;
  
  /**
   * Factory that creates a {@link CassandraSchema}.
   */
  @SuppressWarnings("UnusedDeclaration")
  public class CassandraSchemaFactory implements SchemaFactory {
  
    private static final int DEFAULT_CASSANDRA_PORT = 9042;
    private static final Map<Map<String, Object>, CqlSession> INFO_TO_SESSION =
        new ConcurrentHashMap<>();
    private static final Set<String> SESSION_DEFINING_KEYS =
        ImmutableSet.of("host", "port", "keyspace", "username", "password");
    protected static final Logger LOGGER = CalciteTrace.getPlannerTracer();
  
    public CassandraSchemaFactory() {
      super();
    }
  
    @Override public Schema create(SchemaPlus parentSchema, String name,
        Map<String, Object> operand) {
  
      final Map<String, Object> sessionMap = projectMapOverKeys(operand, SESSION_DEFINING_KEYS);
  
      INFO_TO_SESSION.computeIfAbsent(sessionMap, m -> {
        String host = (String) m.get("host");
        String username = (String) m.get("username");
        String password = (String) m.get("password");
        int port = getPort(m);
  
        if (LOGGER.isDebugEnabled()) {
          LOGGER.debug("Creating session for info {}", m);
        }
        try {
          CqlSessionBuilder builder =
              username != null && password != null
                  ? CqlSession.builder()
                    .addContactPoint(new InetSocketAddress(host, port))
                    .withAuthCredentials(username, password)
                  : CqlSession.builder()
                    .addContactPoint(new InetSocketAddress(host, port));
  
          if (m.containsKey("keyspace")) {
            String keyspace = (String) m.get("keyspace");
            builder = builder.withKeyspace(keyspace);
          }
  
          return builder
              .withLocalDatacenter("datacenter1")
              .build();
        } catch (Exception e) {
          throw new RuntimeException(e);
        }
      });
  
      CqlSession session = INFO_TO_SESSION.get(sessionMap);
  
      String keyspace = session.getKeyspace()
          .map(CqlIdentifier::asInternal)
          .orElse(name);
  
      return new CassandraSchema(session, parentSchema, keyspace, name);
    }
  
    private static Map<String, Object> projectMapOverKeys(
        Map<String, Object> map, Set<String> keysToKeep) {
      return map.entrySet().stream()
          .filter(e -> keysToKeep.contains(e.getKey()))
          .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
    }
  
    private static int getPort(Map<String, Object> map) {
      if (map.containsKey("port")) {
        Object portObj = map.get("port");
        if (portObj instanceof String) {
          return parseInt((String) portObj);
        } else {
          return (int) portObj;
        }
      } else {
        return DEFAULT_CASSANDRA_PORT;
      }
    }
  }
  