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   * 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.
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  package org.apache.beam.sdk.util.construction;
  
  import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkState;
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.anyOf;
  import static org.hamcrest.Matchers.not;
  
  import java.util.List;
  import java.util.concurrent.atomic.AtomicReference;
  import org.apache.beam.sdk.Pipeline.PipelineVisitor;
  import org.apache.beam.sdk.coders.BigEndianLongCoder;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.coders.KvCoder;
  import org.apache.beam.sdk.io.GenerateSequence;
  import org.apache.beam.sdk.io.range.OffsetRange;
  import org.apache.beam.sdk.runners.AppliedPTransform;
  import org.apache.beam.sdk.runners.PTransformOverride;
  import org.apache.beam.sdk.runners.TransformHierarchy.Node;
  import org.apache.beam.sdk.testing.TestPipeline;
  import org.apache.beam.sdk.transforms.Materializations;
  import org.apache.beam.sdk.transforms.PTransform;
  import org.apache.beam.sdk.transforms.ParDo;
  import org.apache.beam.sdk.transforms.View;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.PCollectionView;
  import org.apache.beam.sdk.values.PCollectionViews;
  import org.apache.beam.sdk.values.TupleTag;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList;
  import org.hamcrest.Matchers;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for Pipeline. */
  @RunWith(JUnit4.class)
  @SuppressWarnings({
    "rawtypes", // TODO(https://github.com/apache/beam/issues/20447)
  })
  public class MorePipelineTest {
  
    @Rule public final TestPipeline pipeline = TestPipeline.create();
  
    @Test
    public void testReplaceAllPCollectionView() {
      pipeline.enableAbandonedNodeEnforcement(false);
      pipeline.apply(GenerateSequence.from(0).to(100)).apply(View.asList());
  
      pipeline.replaceAll(
          ImmutableList.of(
              PTransformOverride.of(
                  application -> application.getTransform() instanceof View.AsList,
                  new ViewAsListOverride())));
      pipeline.traverseTopologically(
          new PipelineVisitor.Defaults() {
            @Override
            public CompositeBehavior enterCompositeTransform(Node node) {
              if (!node.isRootNode()) {
                assertThat(
                    node.getTransform().getClass(), not(anyOf(Matchers.equalTo(View.AsList.class))));
              }
              return CompositeBehavior.ENTER_TRANSFORM;
            }
          });
    }
  
    static class ViewAsListOverride<T>
        extends SingleInputOutputOverrideFactory<
            PCollection<T>, PCollectionView<List<T>>, View.AsList<T>> {
      @Override
      public PTransformReplacement<PCollection<T>, PCollectionView<List<T>>> getReplacementTransform(
          AppliedPTransform<PCollection<T>, PCollectionView<List<T>>, View.AsList<T>> transform) {
        return PTransformReplacement.of(
            PTransformReplacements.getSingletonMainInput(transform),
            new FakeViewAsList<>(findPCollectionView(transform)));
      }
    }
  
    static class FakeViewAsList<T> extends PTransform<PCollection<T>, PCollectionView<List<T>>> {
      private final PCollectionView<List<T>> originalView;
  
      FakeViewAsList(PCollectionView<List<T>> originalView) {
        this.originalView = originalView;
      }
  
      @Override
      public PCollectionView<List<T>> expand(PCollection<T> input) {
        Coder<T> inputCoder = input.getCoder();
        PCollection<KV<Long, PCollectionViews.ValueOrMetadata<T, OffsetRange>>> materializationInput =
            input
                .apply("IndexElements", ParDo.of(new View.ToListViewDoFn<>()))
                .setCoder(
                    KvCoder.of(
                        BigEndianLongCoder.of(),
                        PCollectionViews.ValueOrMetadataCoder.create(
                            inputCoder, OffsetRange.Coder.of())));
        PCollectionView<List<T>> view =
            PCollectionViews.listViewWithRandomAccess(
                materializationInput,
                (TupleTag<
                        Materializations.MultimapView<
                            Long, PCollectionViews.ValueOrMetadata<T, OffsetRange>>>)
                    originalView.getTagInternal(),
                (PCollectionViews.TypeDescriptorSupplier<T>) inputCoder::getEncodedTypeDescriptor,
                materializationInput.getWindowingStrategy());
        materializationInput.apply(View.CreatePCollectionView.of(view));
        return view;
      }
    }
  
    private static <InputT, ViewT> PCollectionView<ViewT> findPCollectionView(
        final AppliedPTransform<
                PCollection<InputT>,
                PCollectionView<ViewT>,
                ? extends PTransform<PCollection<InputT>, PCollectionView<ViewT>>>
            transform) {
      final AtomicReference<PCollectionView<ViewT>> viewRef = new AtomicReference<>();
      transform
          .getPipeline()
          .traverseTopologically(
              new PipelineVisitor.Defaults() {
                // Stores whether we have entered the expected composite view transform.
                private boolean tracking = false;
  
                @Override
                public CompositeBehavior enterCompositeTransform(Node node) {
                  if (transform.getTransform() == node.getTransform()) {
                    tracking = true;
                  }
                  return super.enterCompositeTransform(node);
                }
  
                @Override
                public void visitPrimitiveTransform(Node node) {
                  if (tracking && node.getTransform() instanceof View.CreatePCollectionView) {
                    View.CreatePCollectionView createViewTransform =
                        (View.CreatePCollectionView) node.getTransform();
                    checkState(
                        viewRef.compareAndSet(null, createViewTransform.getView()),
                        "Found more than one instance of a CreatePCollectionView when"
                            + " attempting to replace %s, found [%s, %s]",
                        transform.getTransform(),
                        viewRef.get(),
                        createViewTransform.getView());
                  }
                }
  
                @Override
                public void leaveCompositeTransform(Node node) {
                  if (transform.getTransform() == node.getTransform()) {
                    tracking = false;
                  }
                }
              });
      checkState(
          viewRef.get() != null,
          "Expected to find CreatePCollectionView contained within %s",
          transform.getTransform());
      return viewRef.get();
    }
  }
  