content: /*
   * Copyright 1999-2025 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.ai.event;
  
  import com.alibaba.nacos.api.ai.listener.NacosAgentCardEvent;
  import com.alibaba.nacos.api.ai.listener.NacosMcpServerEvent;
  import com.alibaba.nacos.client.ai.utils.CacheKeyUtils;
  import com.alibaba.nacos.common.notify.Event;
  import com.alibaba.nacos.common.notify.listener.SmartSubscriber;
  import com.alibaba.nacos.common.utils.CollectionUtils;
  import com.alibaba.nacos.common.utils.ConcurrentHashSet;
  
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.ConcurrentHashMap;
  
  /**
   * Nacos AI module mcp server change notifier.
   *
   * @author xiweng.yy
   */
  public class AiChangeNotifier extends SmartSubscriber {
      
      private final Map<String, Set<McpServerListenerInvoker>> mcpServerListenerInvokers;
      
      private final Map<String, Set<AgentCardListenerInvoker>> agentCardListenerInvokers;
      
      public AiChangeNotifier() {
          this.mcpServerListenerInvokers = new ConcurrentHashMap<>(2);
          this.agentCardListenerInvokers = new ConcurrentHashMap<>(2);
      }
      
      @Override
      public void onEvent(Event event) {
          if (event instanceof McpServerChangedEvent) {
              handleMcpServerChangedEvent((McpServerChangedEvent) event);
          } else if (event instanceof AgentCardChangedEvent) {
              handleAgentCardChangedEvent((AgentCardChangedEvent) event);
          }
      }
      
      private void handleMcpServerChangedEvent(McpServerChangedEvent event) {
          String mcpServerKey = CacheKeyUtils.buildMcpServerKey(event.getMcpName(), event.getVersion());
          if (!isSubscribed(mcpServerKey, mcpServerListenerInvokers)) {
              return;
          }
          NacosMcpServerEvent notifiedEvent = new NacosMcpServerEvent(event.getMcpServer());
          for (McpServerListenerInvoker each : mcpServerListenerInvokers.get(mcpServerKey)) {
              each.invoke(notifiedEvent);
          }
      }
      
      private void handleAgentCardChangedEvent(AgentCardChangedEvent event) {
          String agentCardKey = CacheKeyUtils.buildAgentCardKey(event.getAgentName(), event.getVersion());
          if (!isSubscribed(agentCardKey, agentCardListenerInvokers)) {
              return;
          }
          NacosAgentCardEvent notifiedEvent = new NacosAgentCardEvent(event.getAgentCard());
          for (AgentCardListenerInvoker each : agentCardListenerInvokers.get(agentCardKey)) {
              each.invoke(notifiedEvent);
          }
      }
      
      @Override
      public List<Class<? extends Event>> subscribeTypes() {
          List<Class<? extends Event>> listenedEventTypes = new LinkedList<>();
          listenedEventTypes.add(McpServerChangedEvent.class);
          listenedEventTypes.add(AgentCardChangedEvent.class);
          return listenedEventTypes;
      }
      
      /**
       * register mcp server listener.
       *
       * @param mcpName           name of mcp server
       * @param version           version of mcp server
       * @param listenerInvoker   listener invoker
       */
      public void registerListener(String mcpName, String version, McpServerListenerInvoker listenerInvoker) {
          if (listenerInvoker == null) {
              return;
          }
          String mcpServerKey = CacheKeyUtils.buildMcpServerKey(mcpName, version);
          mcpServerListenerInvokers.compute(mcpServerKey, (key, mcpServerListenerInvokers) -> {
              if (null == mcpServerListenerInvokers) {
                  mcpServerListenerInvokers = new ConcurrentHashSet<>();
              }
              mcpServerListenerInvokers.add(listenerInvoker);
              return mcpServerListenerInvokers;
          });
      }
      
      /**
       * register agent card listener.
       *
       * @param agentName         name of agent card
       * @param version           version of agent card
       * @param listenerInvoker   listener invoker
       */
      public void registerListener(String agentName, String version, AgentCardListenerInvoker listenerInvoker) {
          if (listenerInvoker == null) {
              return;
          }
          String agentCardKey = CacheKeyUtils.buildAgentCardKey(agentName, version);
          agentCardListenerInvokers.compute(agentCardKey, (key, agentCardListenerInvokers) -> {
              if (null == agentCardListenerInvokers) {
                  agentCardListenerInvokers = new ConcurrentHashSet<>();
              }
              agentCardListenerInvokers.add(listenerInvoker);
              return agentCardListenerInvokers;
          });
      }
      
      /**
       * deregister mcp server listener.
       *
       * @param mcpName           name of mcp server
       * @param version           version of mcp server
       * @param listenerInvoker   listener invoker
       */
      public void deregisterListener(String mcpName, String version, McpServerListenerInvoker listenerInvoker) {
          if (listenerInvoker == null) {
              return;
          }
          String mcpServerKey = CacheKeyUtils.buildMcpServerKey(mcpName, version);
          mcpServerListenerInvokers.compute(mcpServerKey, (key, mcpServerListenerInvokers) -> {
              if (null == mcpServerListenerInvokers) {
                  return null;
              }
              mcpServerListenerInvokers.remove(listenerInvoker);
              return mcpServerListenerInvokers.isEmpty() ? null : mcpServerListenerInvokers;
          });
      }
      
      /**
       * deregister agent card listener.
       *
       * @param agentName         name of agent card
       * @param version           version of agent card
       * @param listenerInvoker   listener invoker
       */
      public void deregisterListener(String agentName, String version, AgentCardListenerInvoker listenerInvoker) {
          if (listenerInvoker == null) {
              return;
          }
          String agentCardKey = CacheKeyUtils.buildAgentCardKey(agentName, version);
          agentCardListenerInvokers.compute(agentCardKey, (key, agentCardListenerInvokers) -> {
              if (null == agentCardListenerInvokers) {
                  return null;
              }
              agentCardListenerInvokers.remove(listenerInvoker);
              return agentCardListenerInvokers.isEmpty() ? null : agentCardListenerInvokers;
          });
      }
      
      /**
       * check mcp server is subscribed.
       *
       * @param mcpName name of mcp server
       * @param version version of mcp server
       * @return is mcp server subscribed
       */
      public boolean isMcpServerSubscribed(String mcpName, String version) {
          String mcpServerKey = CacheKeyUtils.buildMcpServerKey(mcpName, version);
          return isSubscribed(mcpServerKey, mcpServerListenerInvokers);
      }
      
      /**
       * check agent card is subscribed.
       *
       * @param agentName name of agent card
       * @param version version of agent card
       * @return is agent card subscribed
       */
      public boolean isAgentCardSubscribed(String agentName, String version) {
          String agentCardKey = CacheKeyUtils.buildAgentCardKey(agentName, version);
          return isSubscribed(agentCardKey, agentCardListenerInvokers);
      }
      
      private <T extends AbstractAiListenerInvoker> boolean isSubscribed(String key,
              Map<String, Set<T>> listenerInvokers) {
          return CollectionUtils.isNotEmpty(listenerInvokers.get(key));
      }
  }
  