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.server;
  
  import org.apache.kafka.clients.NodeApiVersions;
  import org.apache.kafka.common.message.ApiMessageType;
  import org.apache.kafka.common.message.ApiVersionsResponseData;
  import org.apache.kafka.common.requests.ApiVersionsResponse;
  import org.apache.kafka.metadata.MetadataCache;
  import org.apache.kafka.server.common.FinalizedFeatures;
  
  import java.util.Optional;
  import java.util.function.Supplier;
  
  /**
   * The default ApiVersionManager that supports forwarding and has metadata cache, used in brokers.
   * The enabled APIs are determined by the broker listener type and the controller APIs.
   */
  public class DefaultApiVersionManager implements ApiVersionManager {
  
      private final ApiMessageType.ListenerType listenerType;
      private final Supplier<Optional<NodeApiVersions>> nodeApiVersionsSupplier;
      private final BrokerFeatures brokerFeatures;
      private final MetadataCache metadataCache;
      private final boolean enableUnstableLastVersion;
      private final Optional<ClientMetricsManager> clientMetricsManager;
  
      /**
       * DefaultApiVersionManager constructor
       * @param listenerType the listener type
       * @param nodeApiVersionsSupplier the supplier of NodeApiVersions
       * @param brokerFeatures the broker features
       * @param metadataCache the metadata cache, used to get the finalized features and the metadata version
       * @param enableUnstableLastVersion whether to enable unstable last version, see
       *   {@link org.apache.kafka.server.config.ServerConfigs#UNSTABLE_API_VERSIONS_ENABLE_CONFIG}
       * @param clientMetricsManager the client metrics manager, helps to determine whether client telemetry is enabled
       */
      public DefaultApiVersionManager(
              ApiMessageType.ListenerType listenerType,
              Supplier<Optional<NodeApiVersions>> nodeApiVersionsSupplier,
              BrokerFeatures brokerFeatures,
              MetadataCache metadataCache,
              boolean enableUnstableLastVersion,
              Optional<ClientMetricsManager> clientMetricsManager) {
          this.listenerType = listenerType;
          this.nodeApiVersionsSupplier = nodeApiVersionsSupplier;
          this.brokerFeatures = brokerFeatures;
          this.metadataCache = metadataCache;
          this.enableUnstableLastVersion = enableUnstableLastVersion;
          this.clientMetricsManager = clientMetricsManager;
      }
  
      @Override
      public boolean enableUnstableLastVersion() {
          return enableUnstableLastVersion;
      }
  
      @Override
      public ApiMessageType.ListenerType listenerType() {
          return listenerType;
      }
  
      @Override
      public ApiVersionsResponse apiVersionResponse(int throttleTimeMs, boolean alterFeatureLevel0) {
          FinalizedFeatures finalizedFeatures = metadataCache.features();
          Optional<NodeApiVersions> controllerApiVersions = nodeApiVersionsSupplier.get();
          boolean clientTelemetryEnabled = clientMetricsManager.map(ClientMetricsManager::isTelemetryReceiverConfigured).orElse(false);
          ApiVersionsResponseData.ApiVersionCollection apiVersions = controllerApiVersions
                  .map(nodeApiVersions -> ApiVersionsResponse.controllerApiVersions(
                      nodeApiVersions,
                      listenerType,
                      enableUnstableLastVersion,
                      clientTelemetryEnabled))
                  .orElseGet(() -> ApiVersionsResponse.brokerApiVersions(
                      listenerType,
                      enableUnstableLastVersion,
                      clientTelemetryEnabled));
  
          return new ApiVersionsResponse.Builder()
              .setThrottleTimeMs(throttleTimeMs)
              .setApiVersions(apiVersions)
              .setSupportedFeatures(brokerFeatures.supportedFeatures())
              .setFinalizedFeatures(finalizedFeatures.finalizedFeatures())
              .setFinalizedFeaturesEpoch(finalizedFeatures.finalizedFeaturesEpoch())
              .setAlterFeatureLevel0(alterFeatureLevel0)
              .build();
      }
  
      @Override
      public FinalizedFeatures features() {
          return metadataCache.features();
      }
  }
  