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.beam.runners.spark.structuredstreaming.translation.helpers;
  
  import static org.apache.beam.runners.spark.structuredstreaming.translation.helpers.EncoderHelpers.kvEncoder;
  
  import java.util.function.Function;
  import org.apache.beam.sdk.annotations.Internal;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.coders.KvCoder;
  import org.apache.beam.sdk.values.KV;
  import org.apache.spark.sql.Encoder;
  
  @Internal
  public interface EncoderProvider {
    interface Factory<T> extends Function<Coder<T>, Encoder<T>> {
      Factory<?> INSTANCE = EncoderHelpers::encoderFor;
    }
  
    <T> Encoder<T> encoderOf(Coder<T> coder, Factory<T> factory);
  
    default <T> Encoder<T> encoderOf(Coder<T> coder) {
      return coder instanceof KvCoder
          ? (Encoder<T>) kvEncoderOf((KvCoder) coder)
          : encoderOf(coder, encoderFactory());
    }
  
    default <K, V> Encoder<KV<K, V>> kvEncoderOf(KvCoder<K, V> coder) {
      return encoderOf(coder, c -> kvEncoder(keyEncoderOf(coder), valueEncoderOf(coder)));
    }
  
    default <K, V> Encoder<K> keyEncoderOf(KvCoder<K, V> coder) {
      return encoderOf(coder.getKeyCoder(), encoderFactory());
    }
  
    default <K, V> Encoder<V> valueEncoderOf(KvCoder<K, V> coder) {
      return encoderOf(coder.getValueCoder(), encoderFactory());
    }
  
    default <T> Factory<T> encoderFactory() {
      return (Factory<T>) Factory.INSTANCE;
    }
  }
  