/*
    * Copyright 2014 The Netty Project
    *
    * The Netty Project licenses this file to you 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 io.netty.handler.codec.mqtt;
  
  import io.netty.util.CharsetUtil;
  import io.netty.util.internal.ObjectUtil;
  
  /**
   * Mqtt version specific constant values used by multiple classes in mqtt-codec.
   */
  public enum MqttVersion {
      MQTT_3_1("MQIsdp", (byte) 3),
      MQTT_3_1_1("MQTT", (byte) 4),
      MQTT_5("MQTT", (byte) 5);
  
      private final String name;
      private final byte level;
  
      MqttVersion(String protocolName, byte protocolLevel) {
          name = ObjectUtil.checkNotNull(protocolName, "protocolName");
          level = protocolLevel;
      }
  
      public String protocolName() {
          return name;
      }
  
      public byte[] protocolNameBytes() {
          return name.getBytes(CharsetUtil.UTF_8);
      }
  
      public byte protocolLevel() {
          return level;
      }
  
      public static MqttVersion fromProtocolNameAndLevel(String protocolName, byte protocolLevel) {
          MqttVersion mv = null;
          switch (protocolLevel) {
          case 3:
              mv = MQTT_3_1;
              break;
          case 4:
              mv = MQTT_3_1_1;
              break;
          case 5:
              mv = MQTT_5;
              break;
          default:
              break;
          }
          if (mv == null) {
              throw new MqttUnacceptableProtocolVersionException(protocolName + " is an unknown protocol name");
          }
          if (mv.name.equals(protocolName)) {
              return mv;
          }
          throw new MqttUnacceptableProtocolVersionException(protocolName + " and " + protocolLevel + " don't match");
      }
  }