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 org.apache.kafka.common.KafkaFuture;
  import org.apache.kafka.common.internals.KafkaFutureImpl;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  /**
   * The result of the {@link Admin#listTransactions()} call.
   * <p>
   */
  public class ListTransactionsResult {
      private final KafkaFuture<Map<Integer, KafkaFutureImpl<Collection<TransactionListing>>>> future;
  
      ListTransactionsResult(KafkaFuture<Map<Integer, KafkaFutureImpl<Collection<TransactionListing>>>> future) {
          this.future = future;
      }
  
      /**
       * Get all transaction listings. If any of the underlying requests fail, then the future
       * returned from this method will also fail with the first encountered error.
       *
       * @return A future containing the collection of transaction listings. The future completes
       *         when all transaction listings are available and fails after any non-retriable error.
       */
      public KafkaFuture<Collection<TransactionListing>> all() {
          return allByBrokerId().thenApply(map -> {
              List<TransactionListing> allListings = new ArrayList<>();
              for (Collection<TransactionListing> listings : map.values()) {
                  allListings.addAll(listings);
              }
              return allListings;
          });
      }
  
      /**
       * Get a future which returns a map containing the underlying listing future for each broker
       * in the cluster. This is useful, for example, if a partial listing of transactions is
       * sufficient, or if you want more granular error details.
       *
       * @return A future containing a map of futures by broker which complete individually when
       *         their respective transaction listings are available. The top-level future returned
       *         from this method may fail if the admin client is unable to lookup the available
       *         brokers in the cluster.
       */
      public KafkaFuture<Map<Integer, KafkaFuture<Collection<TransactionListing>>>> byBrokerId() {
          KafkaFutureImpl<Map<Integer, KafkaFuture<Collection<TransactionListing>>>> result = new KafkaFutureImpl<>();
          future.whenComplete((brokerFutures, exception) -> {
              if (brokerFutures != null) {
                  Map<Integer, KafkaFuture<Collection<TransactionListing>>> brokerFuturesCopy =
                      new HashMap<>(brokerFutures.size());
                  brokerFuturesCopy.putAll(brokerFutures);
                  result.complete(brokerFuturesCopy);
              } else {
                  result.completeExceptionally(exception);
              }
          });
          return result;
      }
  
      /**
       * Get all transaction listings in a map which is keyed by the ID of respective broker
       * that is currently managing them. If any of the underlying requests fail, then the future
       * returned from this method will also fail with the first encountered error.
       *
       * @return A future containing a map from the broker ID to the transactions hosted by that
       *         broker respectively. This future completes when all transaction listings are
       *         available and fails after any non-retriable error.
       */
      public KafkaFuture<Map<Integer, Collection<TransactionListing>>> allByBrokerId() {
          KafkaFutureImpl<Map<Integer, Collection<TransactionListing>>> allFuture = new KafkaFutureImpl<>();
          Map<Integer, Collection<TransactionListing>> allListingsMap = new HashMap<>();
  
          future.whenComplete((map, topLevelException) -> {
              if (topLevelException != null) {
                  allFuture.completeExceptionally(topLevelException);
                  return;
              }
  
              Set<Integer> remainingResponses = new HashSet<>(map.keySet());
              map.forEach((brokerId, future) ->
                  future.whenComplete((listings, brokerException) -> {
                      if (brokerException != null) {
                          allFuture.completeExceptionally(brokerException);
                      } else if (!allFuture.isDone()) {
                          allListingsMap.put(brokerId, listings);
                          remainingResponses.remove(brokerId);
  
                          if (remainingResponses.isEmpty()) {
                              allFuture.complete(allListingsMap);
                          }
                      }
                  })
              );
          });
  
          return allFuture;
      }
  
  }
  