content: /*
   * Copyright 1999-2023 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.client.naming.event;
  
  import com.alibaba.nacos.api.naming.pojo.Instance;
  import com.alibaba.nacos.common.utils.CollectionUtils;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  /**
   * The differences in instances compared to the last callback.
   *
   * @author lideyou
   */
  public class InstancesDiff {
      
      private final List<Instance> addedInstances = new ArrayList<>();
      
      private final List<Instance> removedInstances = new ArrayList<>();
      
      private final List<Instance> modifiedInstances = new ArrayList<>();
      
      public InstancesDiff() {
      }
      
      public InstancesDiff(List<Instance> addedInstances, List<Instance> removedInstances,
              List<Instance> modifiedInstances) {
          setAddedInstances(addedInstances);
          setRemovedInstances(removedInstances);
          setModifiedInstances(modifiedInstances);
      }
      
      public List<Instance> getAddedInstances() {
          return addedInstances;
      }
      
      public void setAddedInstances(Collection<Instance> addedInstances) {
          this.addedInstances.clear();
          if (CollectionUtils.isNotEmpty(addedInstances)) {
              this.addedInstances.addAll(addedInstances);
          }
      }
      
      public List<Instance> getRemovedInstances() {
          return removedInstances;
      }
      
      public void setRemovedInstances(Collection<Instance> removedInstances) {
          this.removedInstances.clear();
          if (CollectionUtils.isNotEmpty(removedInstances)) {
              this.removedInstances.addAll(removedInstances);
          }
      }
      
      public List<Instance> getModifiedInstances() {
          return modifiedInstances;
      }
      
      public void setModifiedInstances(Collection<Instance> modifiedInstances) {
          this.modifiedInstances.clear();
          if (CollectionUtils.isNotEmpty(modifiedInstances)) {
              this.modifiedInstances.addAll(modifiedInstances);
          }
      }
      
      /**
       * Check if any instances have changed.
       *
       * @return true if there are instances that have changed
       */
      public boolean hasDifferent() {
          return isAdded() || isRemoved() || isModified();
      }
      
      /**
       * Check if any instances have been added.
       *
       * @return true if there are instances that have been added.
       */
      public boolean isAdded() {
          return CollectionUtils.isNotEmpty(this.addedInstances);
      }
      
      /**
       * Check if any instances have been added.
       *
       * @return true if there are instances that have been added.
       */
      public boolean isRemoved() {
          return CollectionUtils.isNotEmpty(this.removedInstances);
      }
      
      /**
       * Check if any instances have been added.
       *
       * @return true if there are instances that have been added.
       */
      public boolean isModified() {
          return CollectionUtils.isNotEmpty(this.modifiedInstances);
      }
  }
  