content: /*
   * Copyright 2020-2023 the original author or authors.
   *
   * 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
   *
   *      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.jun.mqttx.broker.handler;
  
  import com.fasterxml.jackson.core.type.TypeReference;
  import com.jun.mqttx.broker.BrokerHandler;
  import com.jun.mqttx.config.MqttxConfig;
  import com.jun.mqttx.constants.InternalMessageEnum;
  import com.jun.mqttx.consumer.Watcher;
  import com.jun.mqttx.entity.InternalMessage;
  import com.jun.mqttx.entity.Session;
  import com.jun.mqttx.utils.JsonSerializer;
  import com.jun.mqttx.utils.Serializer;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.ChannelOutboundInvoker;
  import io.netty.handler.codec.mqtt.MqttMessage;
  import io.netty.handler.codec.mqtt.MqttMessageType;
  import lombok.extern.slf4j.Slf4j;
  
  import java.util.Optional;
  
  /**
   * {@link MqttMessageType#DISCONNECT} 消息处理器
   *
   * @author Jun
   * @since 1.0.4
   */
  @Slf4j
  @Handler(type = MqttMessageType.DISCONNECT)
  public final class DisconnectHandler extends AbstractMqttSessionHandler implements Watcher {
  
      private final Serializer serializer;
  
      public DisconnectHandler(Serializer serializer, MqttxConfig config) {
          super(config.getCluster().getEnable());
          this.serializer = serializer;
      }
  
      /**
       * 处理 disconnect 报文
       *
       * @param ctx 见 {@link ChannelHandlerContext}
       * @param msg 解包后的数据
       */
      @Override
      public void process(ChannelHandlerContext ctx, MqttMessage msg) {
          // [MQTT-3.1.2-8]
          // If the Will Flag is set to 1 this indicates that, if the Connect request is accepted, a Will Message MUST be
          // stored on the Server and associated with the Network Connection. The Will Message MUST be published when the
          // Network Connection is subsequently closed unless the Will Message has been deleted by the Server on receipt of
          // a DISCONNECT Packet.
          Session session = getSession(ctx);
          session.clearWillMessage();
  
          ctx.close();
      }
  
      @Override
      public void action(byte[] msg) {
          InternalMessage<String> im;
          if (serializer instanceof JsonSerializer se) {
              im = se.deserialize(msg, new TypeReference<>() {
              });
          } else {
              //noinspection unchecked
              im = serializer.deserialize(msg, InternalMessage.class);
          }
  
          Optional.ofNullable(im.getData())
                  .map(ConnectHandler.CLIENT_MAP::get)
                  .map(BrokerHandler.CHANNELS::find)
                  .map(ChannelOutboundInvoker::close);
      }
  
      @Override
      public boolean support(String channel) {
          return InternalMessageEnum.DISCONNECT.getChannel().equals(channel);
      }
  }
  