/*
    * 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.proxy.backend.mysql.handler.admin;
  
  import org.apache.shardingsphere.infra.binder.context.statement.SQLStatementContext;
  import org.apache.shardingsphere.infra.binder.context.statement.type.dml.SelectStatementContext;
  import org.apache.shardingsphere.proxy.backend.context.ProxyContext;
  import org.apache.shardingsphere.proxy.backend.handler.admin.executor.DatabaseAdminExecutor;
  import org.apache.shardingsphere.proxy.backend.handler.admin.executor.DatabaseAdminExecutorCreator;
  import org.apache.shardingsphere.proxy.backend.mysql.handler.admin.executor.MySQLKillProcessExecutor;
  import org.apache.shardingsphere.proxy.backend.mysql.handler.admin.executor.MySQLSetVariableAdminExecutor;
  import org.apache.shardingsphere.proxy.backend.mysql.handler.admin.executor.MySQLUseDatabaseExecutor;
  import org.apache.shardingsphere.proxy.backend.mysql.handler.admin.factory.MySQLSelectAdminExecutorFactory;
  import org.apache.shardingsphere.proxy.backend.mysql.handler.admin.factory.MySQLShowAdminExecutorFactory;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.SQLStatement;
  import org.apache.shardingsphere.sql.parser.statement.core.statement.type.dal.SetStatement;
  import org.apache.shardingsphere.sql.parser.statement.mysql.dal.MySQLKillStatement;
  import org.apache.shardingsphere.sql.parser.statement.mysql.dal.MySQLUseStatement;
  
  import java.util.List;
  import java.util.Optional;
  
  /**
   * Database admin executor creator for MySQL.
   */
  public final class MySQLAdminExecutorCreator implements DatabaseAdminExecutorCreator {
      
      @Override
      public Optional<DatabaseAdminExecutor> create(final SQLStatementContext sqlStatementContext, final String sql, final String databaseName, final List<Object> parameters) {
          if (sqlStatementContext instanceof SelectStatementContext) {
              return MySQLSelectAdminExecutorFactory.newInstance((SelectStatementContext) sqlStatementContext, sql, parameters, databaseName,
                      ProxyContext.getInstance().getContextManager().getMetaDataContexts().getMetaData());
          }
          SQLStatement sqlStatement = sqlStatementContext.getSqlStatement();
          Optional<DatabaseAdminExecutor> showExecutor = MySQLShowAdminExecutorFactory.newInstance(sqlStatement);
          if (showExecutor.isPresent()) {
              return showExecutor;
          }
          if (sqlStatement instanceof MySQLUseStatement) {
              return Optional.of(new MySQLUseDatabaseExecutor((MySQLUseStatement) sqlStatement));
          }
          if (sqlStatement instanceof MySQLKillStatement) {
              return Optional.of(new MySQLKillProcessExecutor((MySQLKillStatement) sqlStatement));
          }
          if (sqlStatement instanceof SetStatement) {
              return Optional.of(new MySQLSetVariableAdminExecutor((SetStatement) sqlStatement));
          }
          return Optional.empty();
      }
      
      @Override
      public String getDatabaseType() {
          return "MySQL";
      }
  }