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;
  
  import java.util.Optional;
  import org.apache.beam.sdk.extensions.euphoria.core.client.operator.base.Operator;
  import org.apache.beam.sdk.transforms.PTransform;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.PCollectionList;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions;
  
  /**
   * Expand operator to a beam {@link PTransform}.
   *
   * @param <InputT> type of input elements
   * @param <OutputT> type of output elements
   * @param <OperatorT> type of operator to expand
   * @deprecated Use Java SDK directly, Euphoria is scheduled for removal in a future release.
   */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  @Deprecated
  public class OperatorTransform<InputT, OutputT, OperatorT extends Operator<OutputT>>
      extends PTransform<PCollectionList<InputT>, PCollection<OutputT>> {
  
    public static <InputT, OutputT, OperatorT extends Operator<OutputT>> PCollection<OutputT> apply(
        OperatorT operator, PCollectionList<InputT> inputs) {
  
      final Optional<OperatorTranslator<InputT, OutputT, OperatorT>> maybeTranslator =
          TranslatorProvider.of(inputs.getPipeline()).findTranslator(operator);
  
      if (maybeTranslator.isPresent()) {
        final PCollection<OutputT> output =
            inputs.apply(
                operator.getName().orElseGet(() -> operator.getClass().getName()),
                new OperatorTransform<>(operator, maybeTranslator.orElse(null)));
        Preconditions.checkState(
            output.getTypeDescriptor() != null,
            "Translator should always return a typed PCollection.");
        return output;
      }
  
      throw new IllegalStateException(
          "Unable to find translator for basic operator ["
              + operator.getClass()
              + "] with name ["
              + operator.getName().orElse(null)
              + "]");
    }
  
    private final OperatorT operator;
    private final OperatorTranslator<InputT, OutputT, OperatorT> translator;
  
    private OperatorTransform(
        OperatorT operator, OperatorTranslator<InputT, OutputT, OperatorT> translator) {
      this.operator = operator;
      this.translator = translator;
    }
  
    @Override
    public PCollection<OutputT> expand(PCollectionList<InputT> inputs) {
      return translator.translate(operator, inputs);
    }
  
    public OperatorT getOperator() {
      return operator;
    }
  }
  