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.clients.admin;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Optional;
  
  import static java.util.stream.Collectors.joining;
  
  /**
   * Encapsulates details about finalized as well as supported features. This is particularly useful
   * to hold the result returned by the {@link Admin#describeFeatures(DescribeFeaturesOptions)} API.
   */
  public class FeatureMetadata {
  
      private final Map<String, FinalizedVersionRange> finalizedFeatures;
  
      private final Optional<Long> finalizedFeaturesEpoch;
  
      private final Map<String, SupportedVersionRange> supportedFeatures;
  
      FeatureMetadata(final Map<String, FinalizedVersionRange> finalizedFeatures,
                             final Optional<Long> finalizedFeaturesEpoch,
                             final Map<String, SupportedVersionRange> supportedFeatures) {
          this.finalizedFeatures = new HashMap<>(finalizedFeatures);
          this.finalizedFeaturesEpoch = finalizedFeaturesEpoch;
          this.supportedFeatures = new HashMap<>(supportedFeatures);
      }
  
      /**
       * Returns a map of finalized feature versions. Each entry in the map contains a key being a
       * feature name and the value being a range of version levels supported by every broker in the
       * cluster.
       */
      public Map<String, FinalizedVersionRange> finalizedFeatures() {
          return new HashMap<>(finalizedFeatures);
      }
  
      /**
       * The epoch for the finalized features.
       * If the returned value is empty, it means the finalized features are absent/unavailable.
       */
      public Optional<Long> finalizedFeaturesEpoch() {
          return finalizedFeaturesEpoch;
      }
  
      /**
       * Returns a map of supported feature versions. Each entry in the map contains a key being a
       * feature name and the value being a range of versions supported by a particular broker in the
       * cluster.
       */
      public Map<String, SupportedVersionRange> supportedFeatures() {
          return new HashMap<>(supportedFeatures);
      }
  
      @Override
      public boolean equals(Object other) {
          if (this == other) {
              return true;
          }
          if (!(other instanceof FeatureMetadata)) {
              return false;
          }
  
          final FeatureMetadata that = (FeatureMetadata) other;
          return Objects.equals(this.finalizedFeatures, that.finalizedFeatures) &&
              Objects.equals(this.finalizedFeaturesEpoch, that.finalizedFeaturesEpoch) &&
              Objects.equals(this.supportedFeatures, that.supportedFeatures);
      }
  
      @Override
      public int hashCode() {
          return Objects.hash(finalizedFeatures, finalizedFeaturesEpoch, supportedFeatures);
      }
  
      private static <ValueType> String mapToString(final Map<String, ValueType> featureVersionsMap) {
          return String.format(
              "{%s}",
              featureVersionsMap
                  .entrySet()
                  .stream()
                  .map(entry -> String.format("(%s -> %s)", entry.getKey(), entry.getValue()))
                  .collect(joining(", "))
          );
      }
  
      @Override
      public String toString() {
          return String.format(
              "FeatureMetadata{finalizedFeatures:%s, finalizedFeaturesEpoch:%s, supportedFeatures:%s}",
              mapToString(finalizedFeatures),
              finalizedFeaturesEpoch.map(Object::toString).orElse("<none>"),
              mapToString(supportedFeatures));
      }
  }
  