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;
  
  import java.util.Objects;
  import java.util.function.Consumer;
  import java.util.function.Function;
  
  /**
   * The {@code Branched} class is used to define the optional parameters when building branches with
   * {@link BranchedKStream}.
   *
   * @param <K> type of record key
   * @param <V> type of record value
   */
  public class Branched<K, V> implements NamedOperation<Branched<K, V>> {
  
      protected final String name;
      protected final Function<? super KStream<K, V>, ? extends KStream<K, V>> chainFunction;
      protected final Consumer<? super KStream<K, V>> chainConsumer;
  
      protected Branched(final String name,
                         final Function<? super KStream<K, V>, ? extends KStream<K, V>> chainFunction,
                         final Consumer<? super KStream<K, V>> chainConsumer) {
          this.name = name;
          this.chainFunction = chainFunction;
          this.chainConsumer = chainConsumer;
      }
  
      protected Branched(final Branched<K, V> branched) {
          this(branched.name, branched.chainFunction, branched.chainConsumer);
      }
  
      /**
       * Create an instance of {@code Branched} with provided branch name suffix.
       *
       * @param name
       *        the branch name suffix to be used (see {@link BranchedKStream} description for details)
       *
       * @param <K> key type
       * @param <V> value type
       *
       * @return a new instance of {@code Branched}
       */
      public static <K, V> Branched<K, V> as(final String name) {
          Objects.requireNonNull(name, "name cannot be null");
          return new Branched<>(name, null, null);
      }
  
      /**
       * Create an instance of {@code Branched} with provided chain function.
       *
       * @param chain
       *        A function that will be applied to the branch. If the provided function returns
       *        {@code null}, its result is ignored, otherwise it is added to the {@code Map} returned
       *        by {@link BranchedKStream#defaultBranch()} or {@link BranchedKStream#noDefaultBranch()} (see
       *        {@link BranchedKStream} description for details).
       *
       * @param <K> key type
       * @param <V> value type
       *
       * @return a new instance of {@code Branched}
       */
      public static <K, V> Branched<K, V> withFunction(
              final Function<? super KStream<K, V>, ? extends KStream<K, V>> chain
      ) {
          Objects.requireNonNull(chain, "chain function cannot be null");
          return new Branched<>(null, chain, null);
      }
  
      /**
       * Create an instance of {@code Branched} with provided chain consumer.
       *
       * @param chain
       *        A consumer to which the branch will be sent. If a consumer is provided,
       *        the respective branch will not be added to the resulting {@code Map} returned
       *        by {@link BranchedKStream#defaultBranch()} or {@link BranchedKStream#noDefaultBranch()} (see
       *        {@link BranchedKStream} description for details).
       *
       * @param <K> key type
       * @param <V> value type
       *
       * @return a new instance of {@code Branched}
       */
      public static <K, V> Branched<K, V> withConsumer(final Consumer<KStream<K, V>> chain) {
          Objects.requireNonNull(chain, "chain consumer cannot be null");
          return new Branched<>(null, null, chain);
      }
  
      /**
       * Create an instance of {@code Branched} with provided chain function and branch name suffix.
       *
       * @param chain
       *        A function that will be applied to the branch. If the provided function returns
       *        {@code null}, its result is ignored, otherwise it is added to the {@code Map} returned
       *        by {@link BranchedKStream#defaultBranch()} or {@link BranchedKStream#noDefaultBranch()} (see
       *        {@link BranchedKStream} description for details).
       * @param name
       *        the branch name suffix to be used. If {@code null}, a default branch name suffix will be generated
       *        (see {@link BranchedKStream} description for details)
       *
       * @param <K> key type
       * @param <V> value type
       *
       * @return a new instance of {@code Branched}
       */
      public static <K, V> Branched<K, V> withFunction(
          final Function<? super KStream<K, V>, ? extends KStream<K, V>> chain,
          final String name
      ) {
          Objects.requireNonNull(chain, "chain function cannot be null");
          return new Branched<>(name, chain, null);
      }
  
      /**
       * Create an instance of {@code Branched} with provided chain consumer and branch name suffix.
       *
       * @param chain
       *        A consumer to which the branch will be sent. If a non-null consumer is provided,
       *        the respective branch will not be added to the resulting {@code Map} returned
       *        by {@link BranchedKStream#defaultBranch()} or {@link BranchedKStream#noDefaultBranch()} (see
       *        {@link BranchedKStream} description for details).
       * @param name
       *        the branch name suffix to be used. If {@code null}, a default branch name suffix will be generated
       *        (see {@link BranchedKStream} description for details)
       *
       * @param <K> key type
       * @param <V> value type
       *
       * @return a new instance of {@code Branched}
       */
      public static <K, V> Branched<K, V> withConsumer(final Consumer<? super KStream<K, V>> chain,
                                                       final String name) {
          Objects.requireNonNull(chain, "chain consumer cannot be null");
          return new Branched<>(name, null, chain);
      }
  
      /**
       * Configure the instance of {@code Branched} with a branch name suffix.
       *
       * @param name
       *        the branch name suffix to be used. If {@code null} a default branch name suffix will be generated (see
       *        {@link BranchedKStream} description for details)
       *
       * @return {@code this} to facilitate method chaining
       */
      @Override
      public Branched<K, V> withName(final String name) {
          Objects.requireNonNull(name, "name cannot be null");
          return new Branched<>(name, chainFunction, chainConsumer);
      }
  }
  