content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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 com.alibaba.nacos.naming.healthcheck.extend;
  
  import com.alibaba.nacos.api.naming.pojo.AbstractHealthChecker;
  import com.alibaba.nacos.naming.healthcheck.HealthCheckProcessor;
  import com.alibaba.nacos.naming.healthcheck.HealthCheckType;
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.beans.BeansException;
  import org.springframework.beans.factory.BeanFactory;
  import org.springframework.beans.factory.BeanFactoryAware;
  import org.springframework.beans.factory.config.SingletonBeanRegistry;
  import org.springframework.stereotype.Component;
  
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.ServiceLoader;
  import java.util.Set;
  
  /**
   * @author XCXCXCXCX
   */
  @Component
  public class HealthCheckExtendProvider implements BeanFactoryAware {
  
      private static final Logger LOGGER = LoggerFactory.getLogger(HealthCheckExtendProvider.class);
  
      private ServiceLoader<HealthCheckProcessor> processorLoader
          = ServiceLoader.load(HealthCheckProcessor.class);
  
      private ServiceLoader<AbstractHealthChecker> checkerLoader
          = ServiceLoader.load(AbstractHealthChecker.class);
  
      private SingletonBeanRegistry registry;
  
      public void init(){
          loadExtend();
      }
  
      private void loadExtend() {
          Iterator<HealthCheckProcessor> processorIt = processorLoader.iterator();
          Iterator<AbstractHealthChecker> healthCheckerIt = checkerLoader.iterator();
  
          Set<String> origin = new HashSet<>();
          for(HealthCheckType type : HealthCheckType.values()){
              origin.add(type.name());
          }
          Set<String> processorType = new HashSet<>();
          Set<String> healthCheckerType = new HashSet<>();
          processorType.addAll(origin);
          healthCheckerType.addAll(origin);
  
          while(processorIt.hasNext()){
              HealthCheckProcessor processor = processorIt.next();
              String type = processor.getType();
              if(processorType.contains(type)){
                  throw new RuntimeException("More than one processor of the same type was found : [type=\"" + type + "\"]");
              }
              processorType.add(type);
              registry.registerSingleton(lowerFirstChar(processor.getClass().getSimpleName()), processor);
          }
  
          while(healthCheckerIt.hasNext()){
              AbstractHealthChecker checker = healthCheckerIt.next();
              String type = checker.getType();
              if(healthCheckerType.contains(type)){
                  throw new RuntimeException("More than one healthChecker of the same type was found : [type=\"" + type + "\"]");
              }
              healthCheckerType.add(type);
              HealthCheckType.registerHealthChecker(checker.getType(), checker.getClass());
          }
          if(!processorType.equals(healthCheckerType)){
              throw new RuntimeException("An unmatched processor and healthChecker are detected in the extension package.");
          }
          if(processorType.size() > origin.size()){
              processorType.removeAll(origin);
              LOGGER.debug("init health plugin : types=" + processorType);
          }
      }
  
      private String lowerFirstChar(String simpleName) {
          if(StringUtils.isBlank(simpleName)){
              throw new IllegalArgumentException("can't find extend processor class name");
          }
          return String.valueOf(simpleName.charAt(0)).toLowerCase() + simpleName.substring(1);
      }
  
      @Override
      public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
          if(beanFactory instanceof SingletonBeanRegistry){
              this.registry = (SingletonBeanRegistry) beanFactory;
          }
      }
  }
  