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.renderer;
  
  import com.google.errorprone.annotations.FormatMethod;
  import com.google.errorprone.annotations.FormatString;
  import java.util.HashMap;
  import java.util.Map;
  import org.apache.beam.model.pipeline.v1.RunnerApi;
  import org.apache.beam.sdk.util.construction.graph.PipelineNode;
  import org.apache.beam.sdk.util.construction.graph.QueryablePipeline;
  
  /**
   * A DOT renderer for BEAM portable {@link org.apache.beam.model.pipeline.v1.RunnerApi.Pipeline}.
   */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  class PortablePipelineDotRenderer {
    private final StringBuilder dotBuilder = new StringBuilder();
    private final Map<String, Integer> valueToProducerNodeId = new HashMap<>();
    private int indent;
    private int nextNodeId;
  
    private PortablePipelineDotRenderer() {}
  
    static String toDotString(RunnerApi.Pipeline pipeline) {
      return new PortablePipelineDotRenderer().toDot(pipeline);
    }
  
    private String toDot(RunnerApi.Pipeline pipeline) {
      final QueryablePipeline p =
          QueryablePipeline.forTransforms(
              pipeline.getRootTransformIdsList(), pipeline.getComponents());
  
      begin();
  
      for (PipelineNode.PTransformNode transform : p.getTopologicallyOrderedTransforms()) {
        visitTransform(transform);
      }
  
      end();
  
      return dotBuilder.toString();
    }
  
    private void visitTransform(PipelineNode.PTransformNode node) {
      final int nodeId = nextNodeId++;
      final RunnerApi.PTransform transform = node.getTransform();
      writeLine(
          "%d [label=\"%s\\n%s\"]",
          nodeId,
          escapeString(transform.getUniqueName()),
          escapeString(transform.getSpec().getUrn()));
  
      transform.getOutputsMap().values().forEach(x -> valueToProducerNodeId.put(x, nodeId));
  
      transform
          .getInputsMap()
          .forEach(
              (key, value) -> {
                final int producerId = valueToProducerNodeId.get(value);
                String style = "solid";
                writeLine(
                    "%d -> %d [style=%s label=\"%s\"]",
                    producerId,
                    nodeId,
                    style,
                    escapeString(value.substring(value.lastIndexOf('_') + 1)));
              });
    }
  
    private void begin() {
      writeLine("digraph {");
      enterBlock();
      writeLine("rankdir=LR");
    }
  
    private void end() {
      exitBlock();
      writeLine("}");
    }
  
    private void enterBlock() {
      indent += 4;
    }
  
    private void exitBlock() {
      indent -= 4;
    }
  
    @FormatMethod
    private void writeLine(@FormatString String format, Object... args) {
      if (indent != 0) {
        dotBuilder.append(String.format("%-" + indent + "s", ""));
      }
      dotBuilder.append(String.format(format, args));
      dotBuilder.append(System.lineSeparator());
    }
  
    private static String escapeString(String x) {
      return x.replace("\"", "\\\"");
    }
  }
  