/**
 * 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 kafka.javaapi.consumer;


import java.util.List;
import java.util.Map;
import kafka.consumer.KafkaStream;
import kafka.consumer.TopicFilter;
import kafka.message.Message;
import kafka.serializer.Decoder;

public interface ConsumerConnector {
  /**
   *  Create a list of MessageStreams of type T for each topic.
   *
   *  @param topicCountMap  a map of (topic, #streams) pair
   *  @param decoder a decoder that converts from Message to T
   *  @return a map of (topic, list of  KafkaStream) pairs.
   *          The number of items in the list is #streams. Each stream supports
   *          an iterator over message/metadata pairs.
   */
  public <T> Map<String, List<KafkaStream<T>>> createMessageStreams(
      Map<String, Integer> topicCountMap, Decoder<T> decoder);
  public Map<String, List<KafkaStream<Message>>> createMessageStreams(
      Map<String, Integer> topicCountMap);

  /**
   *  Create a list of MessageAndTopicStreams containing messages of type T.
   *
   *  @param topicFilter a TopicFilter that specifies which topics to
   *                    subscribe to (encapsulates a whitelist or a blacklist).
   *  @param numStreams the number of message streams to return.
   *  @param decoder a decoder that converts from Message to T
   *  @return a list of KafkaStream. Each stream supports an
   *          iterator over its MessageAndMetadata elements.
   */
  public <T> List<KafkaStream<T>> createMessageStreamsByFilter(
      TopicFilter topicFilter, int numStreams, Decoder<T> decoder);
  public List<KafkaStream<Message>> createMessageStreamsByFilter(
      TopicFilter topicFilter, int numStreams);
  public List<KafkaStream<Message>> createMessageStreamsByFilter(
      TopicFilter topicFilter);

  /**
   *  Commit the offsets of all broker partitions connected by this connector.
   */
  public void commitOffsets();

  /**
   *  Shut down the connector
   */
  public void shutdown();
}