content: /*
   * 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 io.airlift.configuration;
  
  import com.google.inject.Binder;
  import com.google.inject.Module;
  
  import java.util.Optional;
  import java.util.function.Predicate;
  
  import static io.airlift.configuration.ConfigurationAwareModule.combine;
  import static java.util.Objects.requireNonNull;
  
  public class ConditionalModule<T>
          extends AbstractConfigurationAwareModule
  {
      /**
       * @deprecated Use {@link #conditionalModule} instead
       */
      @Deprecated
      public static <T> Module installModuleIf(Class<T> config, Predicate<T> predicate, Module module, Module otherwise)
      {
          return conditionalModule(config, predicate, module, otherwise);
      }
  
      /**
       * @deprecated Use {@link #conditionalModule} instead
       */
      @Deprecated
      public static <T> Module installModuleIf(Class<T> config, Predicate<T> predicate, Module module)
      {
          return conditionalModule(config, predicate, module);
      }
  
      public static <T> Module conditionalModule(Class<T> config, Predicate<T> predicate, Module module, Module otherwise)
      {
          return combine(
                  conditionalModule(config, predicate, module),
                  conditionalModule(config, predicate.negate(), otherwise));
      }
  
      public static <T> Module conditionalModule(Class<T> config, String prefix, Predicate<T> predicate, Module module, Module otherwise)
      {
          return combine(
                  conditionalModule(config, prefix, predicate, module),
                  conditionalModule(config, prefix, predicate.negate(), otherwise));
      }
  
      public static <T> Module conditionalModule(Class<T> config, Predicate<T> predicate, Module module)
      {
          return new ConditionalModule<>(config, Optional.empty(), predicate, module);
      }
  
      public static <T> Module conditionalModule(Class<T> config, String prefix, Predicate<T> predicate, Module module)
      {
          return new ConditionalModule<>(config, Optional.of(prefix), predicate, module);
      }
  
      private final Class<T> config;
      private final Optional<String> prefix;
      private final Predicate<T> predicate;
      private final Module module;
  
      private ConditionalModule(Class<T> config, Optional<String> prefix, Predicate<T> predicate, Module module)
      {
          this.config = requireNonNull(config, "config is null");
          this.prefix = requireNonNull(prefix, "prefix is null");
          this.predicate = requireNonNull(predicate, "predicate is null");
          this.module = requireNonNull(module, "module is null");
      }
  
      @Override
      protected void setup(Binder binder)
      {
          T configuration = prefix
                  .map(value -> buildConfigObject(config, value))
                  .orElseGet(() -> buildConfigObject(config));
          if (predicate.test(configuration)) {
              install(module);
          }
      }
  }
  