/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF 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
    *
    *     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 org.apache.shardingsphere.db.protocol.mysql.packet.handshake;
  
  import com.google.common.base.Preconditions;
  import lombok.Getter;
  import lombok.RequiredArgsConstructor;
  import org.apache.shardingsphere.db.protocol.mysql.packet.MySQLPacket;
  import org.apache.shardingsphere.db.protocol.mysql.payload.MySQLPacketPayload;
  
  import java.util.Arrays;
  
  /**
   * MySQL authentication switch request packet.
   *
   * @see <a href="https://dev.mysql.com/doc/dev/mysql-server/latest/page_protocol_connection_phase_packets_protocol_auth_switch_request.html">AuthSwitchRequest</a>
   */
  @RequiredArgsConstructor
  public final class MySQLAuthSwitchRequestPacket extends MySQLPacket {
      
      /**
       * Header of MySQL auth switch request packet.
       */
      public static final int HEADER = 0xfe;
      
      @Getter
      private final String authPluginName;
      
      @Getter
      private final MySQLAuthenticationPluginData authPluginData;
      
      public MySQLAuthSwitchRequestPacket(final MySQLPacketPayload payload) {
          Preconditions.checkArgument(HEADER == payload.readInt1(), "Header of MySQL auth switch request packet must be `0xfe`.");
          authPluginName = payload.readStringNul();
          String strAuthPluginData = payload.readStringNul();
          authPluginData = new MySQLAuthenticationPluginData(Arrays.copyOfRange(strAuthPluginData.getBytes(), 0, 8),
                  Arrays.copyOfRange(strAuthPluginData.getBytes(), 8, 20));
      }
      
      @Override
      protected void write(final MySQLPacketPayload payload) {
          payload.writeInt1(HEADER);
          payload.writeStringNul(authPluginName);
          payload.writeStringNul(new String(authPluginData.getAuthenticationPluginData()));
      }
  }