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.sdk.extensions.euphoria.core.translate.provider;
  
  import static java.util.Objects.requireNonNull;
  
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  import java.util.Optional;
  import org.apache.beam.sdk.extensions.euphoria.core.client.operator.base.Operator;
  import org.apache.beam.sdk.extensions.euphoria.core.translate.OperatorTranslator;
  import org.apache.beam.sdk.extensions.euphoria.core.translate.TranslatorProvider;
  
  /**
   * An implementation of {@link TranslatorProvider} which allows to stack other {@link
   * TranslatorProvider TranslatorProviders} in order given on construction time.
   */
  /** @deprecated Use Java SDK directly, Euphoria is scheduled for removal in a future release. */
  @Deprecated
  public class CompositeProvider implements TranslatorProvider {
  
    private final List<TranslatorProvider> orderedTranslatorsChain;
  
    public static CompositeProvider of(List<TranslatorProvider> orderedTranslatorsChain) {
      return new CompositeProvider(orderedTranslatorsChain);
    }
  
    public static CompositeProvider of(TranslatorProvider... orderedTranslatorsChain) {
      requireNonNull(orderedTranslatorsChain);
      return new CompositeProvider(Arrays.asList(orderedTranslatorsChain));
    }
  
    private CompositeProvider(List<TranslatorProvider> orderedTranslatorsChain) {
      requireNonNull(orderedTranslatorsChain);
      this.orderedTranslatorsChain = Collections.unmodifiableList(orderedTranslatorsChain);
    }
  
    /**
     * Returns first {@code Optional<OperatorTranslator<InputT, OutputT, OperatorT>>} which {@link
     * OperatorTranslator#canTranslate(Operator) can translate} given operator.
     *
     * <p>Translators are acquired by calling {@link TranslatorProvider#findTranslator(Operator)} on
     * {@link TranslatorProvider TranslatorProviders} from list given at construction time in given
     * order.
     *
     * @param operator operator to translate
     * @param <InputT> the type of input elements
     * @param <OutputT> the type of output elements
     * @param <OperatorT> the type of the euphoria operator
     * @return first {@code Optional<OperatorTranslator<InputT, OutputT, OperatorT>>} which {@link
     *     OperatorTranslator#canTranslate(Operator) can translate} given operator.
     */
    @Override
    public <InputT, OutputT, OperatorT extends Operator<OutputT>>
        Optional<OperatorTranslator<InputT, OutputT, OperatorT>> findTranslator(OperatorT operator) {
  
      for (TranslatorProvider provider : orderedTranslatorsChain) {
        Optional<OperatorTranslator<InputT, OutputT, OperatorT>> maybeTranslator =
            provider.findTranslator(operator);
  
        if (maybeTranslator.isPresent() && maybeTranslator.get().canTranslate(operator)) {
          return maybeTranslator;
        }
      }
  
      return Optional.empty();
    }
  }
  