content: /*
   * LibertyBans
   * Copyright © 2021 Anand Beh
   *
   * LibertyBans is free software: you can redistribute it and/or modify
   * it under the terms of the GNU Affero General Public License as
   * published by the Free Software Foundation, either version 3 of the
   * License, or (at your option) any later version.
   *
   * LibertyBans is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU Affero General Public License for more details.
   *
   * You should have received a copy of the GNU Affero General Public License
   * along with LibertyBans. If not, see <https://www.gnu.org/licenses/>
   * and navigate to version 3 of the GNU Affero General Public License.
   */
  
  package space.arim.libertybans.core.database.flyway;
  
  import org.jooq.ConnectionProvider;
  import org.jooq.DSLContext;
  import org.jooq.impl.DSL;
  
  import java.sql.Connection;
  import java.sql.DatabaseMetaData;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  import java.util.Objects;
  
  final class TableExists {
  
  	private final String tableName;
  
  	TableExists(String tableName) {
  		this.tableName = Objects.requireNonNull(tableName, "tableName");
  	}
  
  	boolean exists(DSLContext context) throws SQLException {
  
  		ConnectionProvider connectionProvider = context.configuration().connectionProvider();
  		Connection connection = connectionProvider.acquire();
  		assert connection != null : "Null connection";
  		try {
  			String currentSchema = context
  					.select(DSL.currentSchema())
  					.fetchSingle()
  					.value1();
  			DatabaseMetaData metaData = connection.getMetaData();
  			// Be VERY CAREFUL only to select from our own database (schema)
  			try (ResultSet tables = metaData.getTables(null, currentSchema, "%", new String[] {"TABLE"})) {
  
  				while (tables.next()) {
  					String foundTable = tables.getString("TABLE_NAME");
  					if (foundTable.equalsIgnoreCase(tableName)) {
  						return true;
  					}
  				}
  			}
  			return false;
  		} finally {
  			connectionProvider.release(connection);
  		}
  	}
  }
  