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.kafka.streams.kstream.internals;
  
  import org.apache.kafka.clients.producer.internals.BuiltInPartitioner;
  import org.apache.kafka.common.Cluster;
  import org.apache.kafka.common.Node;
  import org.apache.kafka.common.PartitionInfo;
  import org.apache.kafka.common.serialization.IntegerSerializer;
  import org.apache.kafka.common.serialization.StringSerializer;
  import org.apache.kafka.streams.kstream.TimeWindowedSerializer;
  import org.apache.kafka.streams.kstream.Windowed;
  
  import org.junit.jupiter.api.Test;
  
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  import java.util.Optional;
  import java.util.Random;
  import java.util.Set;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  public class WindowedStreamPartitionerTest {
  
      private final String topicName = "topic";
  
      private final IntegerSerializer intSerializer = new IntegerSerializer();
      private final StringSerializer stringSerializer = new StringSerializer();
  
      private final List<PartitionInfo> infos = Arrays.asList(
              new PartitionInfo(topicName, 0, Node.noNode(), new Node[0], new Node[0]),
              new PartitionInfo(topicName, 1, Node.noNode(), new Node[0], new Node[0]),
              new PartitionInfo(topicName, 2, Node.noNode(), new Node[0], new Node[0]),
              new PartitionInfo(topicName, 3, Node.noNode(), new Node[0], new Node[0]),
              new PartitionInfo(topicName, 4, Node.noNode(), new Node[0], new Node[0]),
              new PartitionInfo(topicName, 5, Node.noNode(), new Node[0], new Node[0])
      );
  
      private final Cluster cluster = new Cluster("cluster", Collections.singletonList(Node.noNode()), infos,
              Collections.emptySet(), Collections.emptySet());
  
      @Test
      public void testCopartitioning() {
          final Random rand = new Random();
          final WindowedSerializer<Integer> timeWindowedSerializer = new TimeWindowedSerializer<>(intSerializer);
          final WindowedStreamPartitioner<Integer, String> streamPartitioner = new WindowedStreamPartitioner<>(timeWindowedSerializer);
  
          for (int k = 0; k < 10; k++) {
              final Integer key = rand.nextInt();
              final byte[] keyBytes = intSerializer.serialize(topicName, key);
  
              final String value = key.toString();
  
              final Set<Integer> expected = Set.of(BuiltInPartitioner.partitionForKey(keyBytes, cluster.partitionsForTopic(topicName).size()));
  
              for (int w = 1; w < 10; w++) {
                  final TimeWindow window = new TimeWindow(10 * w, 20 * w);
  
                  final Windowed<Integer> windowedKey = new Windowed<>(key, window);
                  final Optional<Set<Integer>> actual = streamPartitioner.partitions(topicName, windowedKey, value, infos.size());
  
                  assertTrue(actual.isPresent());
                  assertEquals(expected, actual.get());
              }
          }
      }
  }
  