/*
    * 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.data.pipeline.mysql.ingest;
  
  import com.google.common.base.Preconditions;
  import org.apache.shardingsphere.data.pipeline.mysql.ingest.binlog.BinlogPosition;
  import org.apache.shardingsphere.data.pipeline.core.ingest.position.DialectIngestPositionManager;
  
  import javax.sql.DataSource;
  import java.sql.Connection;
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  
  /**
   * Ingest position manager for MySQL.
   */
  public final class MySQLIngestPositionManager implements DialectIngestPositionManager {
      
      @Override
      public BinlogPosition init(final DataSource dataSource, final String slotNameSuffix) throws SQLException {
          try (Connection connection = dataSource.getConnection()) {
              return getBinlogPosition(connection);
          }
      }
      
      @Override
      public BinlogPosition init(final String data) {
          String[] array = data.split("#");
          Preconditions.checkArgument(2 == array.length, "Unknown binlog position: %s", data);
          return new BinlogPosition(array[0], Long.parseLong(array[1]), 0L);
      }
      
      private BinlogPosition getBinlogPosition(final Connection connection) throws SQLException {
          String filename;
          long position;
          long serverId;
          try (
                  PreparedStatement preparedStatement = connection.prepareStatement("SHOW MASTER STATUS");
                  ResultSet resultSet = preparedStatement.executeQuery()) {
              resultSet.next();
              filename = resultSet.getString(1);
              position = resultSet.getLong(2);
          }
          try (
                  PreparedStatement preparedStatement = connection.prepareStatement("SHOW VARIABLES LIKE 'server_id'");
                  ResultSet resultSet = preparedStatement.executeQuery()) {
              resultSet.next();
              serverId = resultSet.getLong(2);
          }
          return new BinlogPosition(filename, position, serverId);
      }
      
      @Override
      public String getDatabaseType() {
          return "MySQL";
      }
  }