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 static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkArgument;
  import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkNotNull;
  
  import java.lang.reflect.Method;
  import java.lang.reflect.Proxy;
  import java.util.Collection;
  import org.apache.beam.sdk.options.Validation.Required;
  import org.apache.beam.sdk.util.common.ReflectHelpers;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Collections2;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Ordering;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.SortedSetMultimap;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.TreeMultimap;
  
  /** Validates that the {@link PipelineOptions} conforms to all the {@link Validation} criteria. */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  public class PipelineOptionsValidator {
    /**
     * Validates that the passed {@link PipelineOptions} conforms to all the validation criteria from
     * the passed in interface.
     *
     * <p>Note that the interface requested must conform to the validation criteria specified on
     * {@link PipelineOptions#as(Class)}.
     *
     * @param klass The interface to fetch validation criteria from.
     * @param options The {@link PipelineOptions} to validate.
     * @return Validated options.
     */
    public static <T extends PipelineOptions> T validate(Class<T> klass, PipelineOptions options) {
      return validate(klass, options, false);
    }
  
    /**
     * Validates that the passed {@link PipelineOptions} from command line interface (CLI) conforms to
     * all the validation criteria from the passed in interface.
     *
     * <p>Note that the interface requested must conform to the validation criteria specified on
     * {@link PipelineOptions#as(Class)}.
     *
     * @param klass The interface to fetch validation criteria from.
     * @param options The {@link PipelineOptions} to validate.
     * @return Validated options.
     */
    public static <T extends PipelineOptions> T validateCli(Class<T> klass, PipelineOptions options) {
      return validate(klass, options, true);
    }
  
    private static <T extends PipelineOptions> T validate(
        Class<T> klass, PipelineOptions options, boolean isCli) {
      checkNotNull(klass);
      checkNotNull(options);
      checkArgument(Proxy.isProxyClass(options.getClass()));
      checkArgument(Proxy.getInvocationHandler(options) instanceof ProxyInvocationHandler);
  
      // Ensure the methods for T are registered on the ProxyInvocationHandler
      T asClassOptions = options.as(klass);
  
      ProxyInvocationHandler handler =
          (ProxyInvocationHandler) Proxy.getInvocationHandler(asClassOptions);
  
      SortedSetMultimap<String, Method> requiredGroups =
          TreeMultimap.create(
              Ordering.natural(), PipelineOptionsFactory.MethodNameComparator.INSTANCE);
      for (Method method : ReflectHelpers.getClosureOfMethodsOnInterface(klass)) {
        Required requiredAnnotation = method.getAnnotation(Validation.Required.class);
        if (requiredAnnotation != null) {
          if (requiredAnnotation.groups().length > 0) {
            for (String requiredGroup : requiredAnnotation.groups()) {
              requiredGroups.put(requiredGroup, method);
            }
          } else {
            if (isCli) {
              checkArgument(
                  handler.invoke(asClassOptions, method, null) != null,
                  "Missing required value for [--%s, \"%s\"]. ",
                  handler.getOptionName(method),
                  getDescription(method));
            } else {
              checkArgument(
                  handler.invoke(asClassOptions, method, null) != null,
                  "Missing required value for [%s, \"%s\"]. ",
                  method,
                  getDescription(method));
            }
          }
        }
      }
  
      for (String requiredGroup : requiredGroups.keySet()) {
        if (!verifyGroup(handler, asClassOptions, requiredGroups.get(requiredGroup))) {
          throw new IllegalArgumentException(
              "Missing required value for group ["
                  + requiredGroup
                  + "]. At least one of the following properties "
                  + Collections2.transform(
                      requiredGroups.get(requiredGroup), ReflectHelpers::formatMethod)
                  + " required. Run with --help="
                  + klass.getSimpleName()
                  + " for more information.");
        }
      }
  
      return asClassOptions;
    }
  
    private static boolean verifyGroup(
        ProxyInvocationHandler handler, PipelineOptions options, Collection<Method> requiredGroup) {
      for (Method m : requiredGroup) {
        if (handler.invoke(options, m, null) != null) {
          return true;
        }
      }
      return false;
    }
  
    private static String getDescription(Method method) {
      Description description = method.getAnnotation(Description.class);
      return description == null ? "" : description.value();
    }
  }
  