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.kafka;
  
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.schema.SchemaPlus;
  import org.apache.calcite.schema.TableFactory;
  
  import org.apache.kafka.clients.consumer.Consumer;
  import org.apache.kafka.clients.consumer.OffsetResetStrategy;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.lang.reflect.InvocationTargetException;
  import java.util.Locale;
  import java.util.Map;
  
  /**
   * Implementation of {@link TableFactory} for Apache Kafka. Currently an Apache Kafka
   * topic is mapping to a STREAM table.
   */
  public class KafkaTableFactory implements TableFactory<KafkaStreamTable> {
    public KafkaTableFactory() {
    }
  
    @Override public KafkaStreamTable create(SchemaPlus schema,
        String name,
        Map<String, Object> operand,
        @Nullable RelDataType rowType) {
      final KafkaTableOptions tableOptionBuilder = new KafkaTableOptions();
  
      tableOptionBuilder.setBootstrapServers(
          (String) operand.getOrDefault(KafkaTableConstants.SCHEMA_BOOTSTRAP_SERVERS, null));
      tableOptionBuilder.setTopicName(
          (String) operand.getOrDefault(KafkaTableConstants.SCHEMA_TOPIC_NAME, null));
  
      final KafkaRowConverter rowConverter;
      if (operand.containsKey(KafkaTableConstants.SCHEMA_ROW_CONVERTER)) {
        String rowConverterClass = (String) operand.get(KafkaTableConstants.SCHEMA_ROW_CONVERTER);
        try {
          final Class<?> klass = Class.forName(rowConverterClass);
          rowConverter = (KafkaRowConverter) klass.getDeclaredConstructor().newInstance();
        } catch (InstantiationException | InvocationTargetException
            | IllegalAccessException | ClassNotFoundException
            | NoSuchMethodException e) {
          final String details =
              String.format(Locale.ROOT,
                  "Failed to create table '%s' with configuration:\n"
                      + "'%s'\n"
                      + "KafkaRowConverter '%s' is invalid",
                  name, operand, rowConverterClass);
          throw new RuntimeException(details, e);
        }
      } else {
        rowConverter = new KafkaRowConverterImpl();
      }
      tableOptionBuilder.setRowConverter(rowConverter);
  
      if (operand.containsKey(KafkaTableConstants.SCHEMA_CONSUMER_PARAMS)) {
        tableOptionBuilder.setConsumerParams(
            (Map<String, String>) operand.get(KafkaTableConstants.SCHEMA_CONSUMER_PARAMS));
      }
      if (operand.containsKey(KafkaTableConstants.SCHEMA_CUST_CONSUMER)) {
        String custConsumerClass = (String) operand.get(KafkaTableConstants.SCHEMA_CUST_CONSUMER);
        try {
          tableOptionBuilder.setConsumer(
              (Consumer) Class.forName(custConsumerClass)
                  .getConstructor(OffsetResetStrategy.class)
                  .newInstance(OffsetResetStrategy.NONE));
        } catch (ClassNotFoundException | NoSuchMethodException | IllegalAccessException
            | InstantiationException | InvocationTargetException e) {
          final String details =
              String.format(Locale.ROOT,
                  "Fail to create table '%s' with configuration:\n"
                      + "'%s'\n"
                      + "KafkaCustConsumer '%s' is invalid",
                  name, operand, custConsumerClass);
          throw new RuntimeException(details, e);
        }
      }
  
      return new KafkaStreamTable(tableOptionBuilder);
    }
  }
  