/*
    * 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.postgresql.check.datasource;
  
  import lombok.extern.slf4j.Slf4j;
  import org.apache.shardingsphere.data.pipeline.core.exception.job.PrepareJobWithCheckPrivilegeFailedException;
  import org.apache.shardingsphere.data.pipeline.core.exception.job.PrepareJobWithoutEnoughPrivilegeException;
  import org.apache.shardingsphere.data.pipeline.core.exception.job.PrepareJobWithoutUserException;
  import org.apache.shardingsphere.data.pipeline.core.checker.DialectDataSourceChecker;
  import org.apache.shardingsphere.infra.exception.core.ShardingSpherePreconditions;
  
  import javax.sql.DataSource;
  import java.sql.Connection;
  import java.sql.DatabaseMetaData;
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  import java.util.Collections;
  
  /**
   * PostgreSQL Data source checker.
   */
  @Slf4j
  public final class PostgreSQLDataSourceChecker implements DialectDataSourceChecker {
      
      private static final String SHOW_GRANTS_SQL = "SELECT * FROM pg_roles WHERE rolname = ?";
      
      @Override
      public void checkPrivilege(final DataSource dataSource) {
          try (Connection connection = dataSource.getConnection(); PreparedStatement preparedStatement = connection.prepareStatement(SHOW_GRANTS_SQL)) {
              DatabaseMetaData metaData = connection.getMetaData();
              preparedStatement.setString(1, metaData.getUserName());
              try (ResultSet resultSet = preparedStatement.executeQuery()) {
                  String username = metaData.getUserName();
                  ShardingSpherePreconditions.checkState(resultSet.next(), () -> new PrepareJobWithoutUserException(username));
                  String isSuperRole = resultSet.getString("rolsuper");
                  String isReplicationRole = resultSet.getString("rolreplication");
                  log.info("checkPrivilege: isSuperRole: {}, isReplicationRole: {}", isSuperRole, isReplicationRole);
                  ShardingSpherePreconditions.checkState("t".equalsIgnoreCase(isSuperRole) || "t".equalsIgnoreCase(isReplicationRole),
                          () -> new PrepareJobWithoutEnoughPrivilegeException(Collections.singleton("REPLICATION")));
              }
          } catch (final SQLException ex) {
              throw new PrepareJobWithCheckPrivilegeFailedException(ex);
          }
      }
      
      @Override
      public void checkVariable(final DataSource dataSource) {
      }
      
      @Override
      public String getDatabaseType() {
          return "PostgreSQL";
      }
  }