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.selector;
  
  import com.alibaba.fastjson.JSON;
  import com.alibaba.fastjson.JSONObject;
  import com.alibaba.fastjson.parser.DefaultJSONParser;
  import com.alibaba.fastjson.parser.deserializer.ObjectDeserializer;
  import com.alibaba.fastjson.serializer.JSONSerializer;
  import com.alibaba.fastjson.serializer.ObjectSerializer;
  import com.alibaba.fastjson.serializer.SerializeWriter;
  import com.alibaba.nacos.api.selector.SelectorType;
  import org.apache.commons.lang3.StringUtils;
  
  import java.io.IOException;
  import java.lang.reflect.Type;
  
  /**
   * Json adapter for class Selector.
   * <p>
   * When deserializing object for class Selector, we should consider to convert the selector to
   * its runtime child class object. And this adapter helps us to finish it.
   *
   * @author nkorange
   * @since 0.7.0
   */
  public class SelectorJsonAdapter implements ObjectDeserializer, ObjectSerializer {
  
      private static SelectorJsonAdapter INSTANCE = new SelectorJsonAdapter();
  
      private SelectorJsonAdapter() {
      }
  
      public static SelectorJsonAdapter getInstance() {
          return INSTANCE;
      }
  
      @Override
      public <T> T deserialze(DefaultJSONParser parser, Type type, Object fieldName) {
  
          JSONObject jsonObj = (JSONObject) parser.parse();
  
          if (jsonObj == null) {
              return null;
          }
  
          String checkType = jsonObj.getString("type");
  
          if (StringUtils.equals(checkType, SelectorType.label.name())) {
              return (T) JSON.parseObject(jsonObj.toJSONString(), LabelSelector.class);
          }
  
          if (StringUtils.equals(checkType, SelectorType.none.name())) {
              return (T) JSON.parseObject(jsonObj.toJSONString(), NoneSelector.class);
          }
  
          return null;
      }
  
      @Override
      public int getFastMatchToken() {
          return 0;
      }
  
      @Override
      public void write(JSONSerializer serializer, Object object, Object fieldName, Type fieldType, int features) throws IOException {
  
          SerializeWriter writer = serializer.getWriter();
          if (object == null) {
              writer.writeNull();
              return;
          }
  
          Selector selector = (Selector) object;
  
          writer.writeFieldValue(',', "type", selector.getType());
  
          if (StringUtils.equals(selector.getType(), SelectorType.label.name())) {
              LabelSelector labelSelector = (LabelSelector) selector;
              writer.writeFieldValue(',', "labels", JSON.toJSONString(labelSelector.getLabels()));
          }
      }
  }
  