/*
 * Copyright (C) 2015 Google Inc.
 *
 * Licensed 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 com.google.cloud.dataflow.sdk.runners;

import com.google.cloud.dataflow.sdk.Pipeline;
import com.google.cloud.dataflow.sdk.transforms.PTransform;
import com.google.cloud.dataflow.sdk.values.PValue;

import java.util.ArrayList;
import java.util.List;

/**
 * Provides a simple {@link com.google.cloud.dataflow.sdk.Pipeline.PipelineVisitor}
 * that records the transformation tree.
 *
 * <p> Provided for internal unit tests.
 */
public class RecordingPipelineVisitor implements Pipeline.PipelineVisitor {

  public final List<PTransform<?, ?>> transforms = new ArrayList<>();
  public final List<PValue> values = new ArrayList<>();

  @Override
  public void enterCompositeTransform(TransformTreeNode node) {
  }

  @Override
  public void leaveCompositeTransform(TransformTreeNode node) {
  }

  @Override
  public void visitTransform(TransformTreeNode node) {
    transforms.add(node.getTransform());
  }

  @Override
  public void visitValue(PValue value, TransformTreeNode producer) {
    values.add(value);
  }
}
