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.options;
  
  import java.beans.Introspector;
  import java.lang.reflect.Method;
  import java.util.Map;
  import java.util.Set;
  import org.apache.beam.sdk.util.common.ReflectHelpers;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.HashMultimap;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableSet;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Multimap;
  
  /** Utilities to reflect over {@link PipelineOptions}. */
  class PipelineOptionsReflector {
    private PipelineOptionsReflector() {}
  
    /**
     * Retrieve metadata for the full set of pipeline options within the type hierarchy of a single
     * {@link PipelineOptions} interface with optional filtering {@link Hidden} options.
     *
     * @see PipelineOptionsReflector#getOptionSpecs(Iterable)
     */
    static Set<PipelineOptionSpec> getOptionSpecs(
        Class<? extends PipelineOptions> optionsInterface, boolean skipHidden) {
      Iterable<Method> methods = ReflectHelpers.getClosureOfMethodsOnInterface(optionsInterface);
      Multimap<String, Method> propsToGetters = getPropertyNamesToGetters(methods);
  
      ImmutableSet.Builder<PipelineOptionSpec> setBuilder = ImmutableSet.builder();
      for (Map.Entry<String, Method> propAndGetter : propsToGetters.entries()) {
        String prop = propAndGetter.getKey();
        Method getter = propAndGetter.getValue();
  
        @SuppressWarnings("unchecked")
        Class<? extends PipelineOptions> declaringClass =
            (Class<? extends PipelineOptions>) getter.getDeclaringClass();
  
        if (!PipelineOptions.class.isAssignableFrom(declaringClass)) {
          continue;
        }
  
        if (skipHidden && declaringClass.isAnnotationPresent(Hidden.class)) {
          continue;
        }
  
        setBuilder.add(PipelineOptionSpec.of(declaringClass, prop, getter));
      }
  
      return setBuilder.build();
    }
  
    /**
     * Retrieve metadata for the full set of pipeline options visible within the type hierarchy
     * closure of the set of input interfaces. An option is "visible" if:
     *
     * <ul>
     *   <li>The option is defined within the interface hierarchy closure of the input {@link
     *       PipelineOptions}.
     *   <li>The defining interface is not marked {@link Hidden}.
     * </ul>
     */
    static Set<PipelineOptionSpec> getOptionSpecs(
        Iterable<Class<? extends PipelineOptions>> optionsInterfaces) {
      ImmutableSet.Builder<PipelineOptionSpec> setBuilder = ImmutableSet.builder();
      for (Class<? extends PipelineOptions> optionsInterface : optionsInterfaces) {
        setBuilder.addAll(getOptionSpecs(optionsInterface, true));
      }
  
      return setBuilder.build();
    }
  
    /**
     * Extract pipeline options and their respective getter methods from a series of {@link Method
     * methods}. A single pipeline option may appear in many methods.
     *
     * @return A mapping of option name to the input methods which declare it.
     */
    static Multimap<String, Method> getPropertyNamesToGetters(Iterable<Method> methods) {
      Multimap<String, Method> propertyNamesToGetters = HashMultimap.create();
      for (Method method : methods) {
        String methodName = method.getName();
        if ((!methodName.startsWith("get") && !methodName.startsWith("is"))
            || method.getParameterTypes().length != 0
            || method.getReturnType() == void.class) {
          continue;
        }
        String propertyName =
            Introspector.decapitalize(
                methodName.startsWith("is") ? methodName.substring(2) : methodName.substring(3));
        propertyNamesToGetters.put(propertyName, method);
      }
      return propertyNamesToGetters;
    }
  }
  