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.coordinator.group.streams;
  
  import org.apache.kafka.coordinator.group.streams.assignor.TopologyDescriber;
  import org.apache.kafka.coordinator.group.streams.topics.ConfiguredSubtopology;
  import org.apache.kafka.image.MetadataImage;
  
  import java.util.Collections;
  import java.util.List;
  import java.util.NoSuchElementException;
  import java.util.Objects;
  import java.util.SortedMap;
  
  /**
   * The topology metadata class is used by the {@link org.apache.kafka.coordinator.group.streams.assignor.TaskAssignor} to get topic and
   * partition metadata for the topology that the streams group using.
   *
   * @param metadataImage  The metadata image
   * @param subtopologyMap The configured subtopologies
   */
  public record TopologyMetadata(MetadataImage metadataImage, SortedMap<String, ConfiguredSubtopology> subtopologyMap) implements TopologyDescriber {
  
      public TopologyMetadata {
          metadataImage = Objects.requireNonNull(metadataImage);
          subtopologyMap = Objects.requireNonNull(Collections.unmodifiableSortedMap(subtopologyMap));
      }
  
      /**
       * Checks whether the given subtopology is associated with a changelog topic.
       *
       * @param subtopologyId String identifying the subtopology.
       * @throws NoSuchElementException if the subtopology ID does not exist.
       * @return true if the subtopology is associated with a changelog topic, false otherwise.
       */
      @Override
      public boolean isStateful(String subtopologyId) {
          final ConfiguredSubtopology subtopology = getSubtopologyOrFail(subtopologyId);
          return !subtopology.stateChangelogTopics().isEmpty();
      }
  
      /**
       * The list of subtopologies in the topology.
       *
       * @return a list of subtopology IDs.
       */
      @Override
      public List<String> subtopologies() {
          return subtopologyMap.keySet().stream().toList();
      }
  
      /**
       * The maximal number of input partitions among all source topics for the given subtopology.
       *
       * @param subtopologyId String identifying the subtopology.
       *
       * @throws NoSuchElementException if the subtopology ID does not exist.
       * @throws IllegalStateException if the subtopology contains no source topics.
       * @return The maximal number of input partitions among all source topics for the given subtopology.
       */
      @Override
      public int maxNumInputPartitions(String subtopologyId) {
          final ConfiguredSubtopology subtopology = getSubtopologyOrFail(subtopologyId);
          return subtopology.numberOfTasks();
      }
  
      private ConfiguredSubtopology getSubtopologyOrFail(String subtopologyId) {
          if (!subtopologyMap.containsKey(subtopologyId)) {
              throw new NoSuchElementException(String.format("Topology does not contain subtopology %s", subtopologyId));
          }
          return subtopologyMap.get(subtopologyId);
      }
  
  }
  