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.util.construction.graph;
  
  import java.util.Set;
  import org.apache.beam.model.pipeline.v1.RunnerApi;
  import org.apache.beam.model.pipeline.v1.RunnerApi.Pipeline;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * TrivialNativeTransformExpander is used to replace transforms with known URNs with their native
   * equivalent.
   */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  public class TrivialNativeTransformExpander {
    private static final Logger LOG = LoggerFactory.getLogger(TrivialNativeTransformExpander.class);
  
    /**
     * Replaces transforms with the known URN with a native equivalent stripping the environment and
     * removing any sub-transforms from the returned pipeline.
     *
     * @param pipeline the pipeline to be trimmed
     * @param knownUrns set of URNs for the runner's native transforms
     * @return the trimmed pipeline
     */
    public static Pipeline forKnownUrns(Pipeline pipeline, Set<String> knownUrns) {
      return makeKnownUrnsPrimitives(pipeline, knownUrns);
    }
  
    private static RunnerApi.Pipeline makeKnownUrnsPrimitives(
        RunnerApi.Pipeline pipeline, Set<String> knownUrns) {
      RunnerApi.Pipeline.Builder trimmedPipeline = pipeline.toBuilder();
      for (String ptransformId : pipeline.getComponents().getTransformsMap().keySet()) {
        // Skip over previously removed transforms from the original pipeline since we iterate
        // over all transforms from the original pipeline and not the trimmed down version.
        RunnerApi.PTransform currentTransform =
            trimmedPipeline.getComponents().getTransformsOrDefault(ptransformId, null);
        if (currentTransform != null && knownUrns.contains(currentTransform.getSpec().getUrn())) {
          LOG.debug(
              "Removing descendants and environment of known native PTransform {}", ptransformId);
          removeDescendants(trimmedPipeline, ptransformId);
          trimmedPipeline
              .getComponentsBuilder()
              .putTransforms(
                  ptransformId,
                  currentTransform.toBuilder().clearSubtransforms().clearEnvironmentId().build());
        }
      }
      return trimmedPipeline.build();
    }
  
    private static void removeDescendants(RunnerApi.Pipeline.Builder pipeline, String parentId) {
      RunnerApi.PTransform parentProto = pipeline.getComponents().getTransformsOrThrow(parentId);
      for (String childId : parentProto.getSubtransformsList()) {
        removeDescendants(pipeline, childId);
        pipeline.getComponentsBuilder().removeTransforms(childId);
      }
    }
  }
  