/*
    * Copyright 2017 LINE Corporation
    *
    * LINE Corporation 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:
    *
    *   https://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.linecorp.centraldogma.client.updater;
  
  import java.lang.reflect.Method;
  
  import javax.annotation.Nullable;
  
  import com.linecorp.centraldogma.common.Revision;
  
  final class RevisionMethodDelegate implements MethodDelegate {
      @Override
      public boolean match(Method thisMethod) {
          return thisMethod.getReturnType() == Revision.class &&
                 thisMethod.getParameterCount() == 0;
      }
  
      @Override
      @Nullable
      public <T> Object invoke(CentralDogmaBeanMethodHandler<T> handler, Object self, Method thisMethod,
                               Method proceed, Object[] args) throws Throwable {
          if (handler.watcher.initialValueFuture().isDone()) {
              return handler.watcher.latest().revision();
          } else {
              return null;
          }
      }
  }