/*
 *
 * MariaDB Client for Java
 *
 * Copyright (c) 2012-2014 Monty Program Ab.
 * Copyright (c) 2015-2020 MariaDB Corporation Ab.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this library; if not, write to Monty Program Ab info@montyprogram.com.
 *
 * This particular MariaDB Client for Java file is work
 * derived from a Drizzle-JDBC. Drizzle-JDBC file which is covered by subject to
 * the following copyright and notice provisions:
 *
 * Copyright (c) 2009-2011, Marcus Eriksson
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * Redistributions of source code must retain the above copyright notice, this list
 * of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice, this
 * list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
 *
 * Neither the name of the driver nor the names of its contributors may not be
 * used to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS  AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 */

package org.mariadb.jdbc;

import java.io.InputStream;
import java.nio.charset.Charset;
import java.sql.*;
import java.util.*;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReentrantLock;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.mariadb.jdbc.internal.com.read.dao.Results;
import org.mariadb.jdbc.internal.com.read.resultset.SelectResultSet;
import org.mariadb.jdbc.internal.logging.Logger;
import org.mariadb.jdbc.internal.logging.LoggerFactory;
import org.mariadb.jdbc.internal.protocol.Protocol;
import org.mariadb.jdbc.internal.util.Utils;
import org.mariadb.jdbc.internal.util.exceptions.ExceptionFactory;
import org.mariadb.jdbc.internal.util.scheduler.SchedulerServiceProviderHolder;
import org.mariadb.jdbc.util.Options;

public class MariaDbStatement implements Statement, Cloneable {

  private static final Pattern identifierPattern =
      Pattern.compile("[0-9a-zA-Z\\$_\\u0080-\\uFFFF]*", Pattern.UNICODE_CASE | Pattern.CANON_EQ);
  private static final Pattern escapePattern = Pattern.compile("[\u0000'\"\b\n\r\t\u001A\\\\]");
  private static final Map<String, String> mapper = new HashMap<>();
  // timeout scheduler
  private static final Logger logger = LoggerFactory.getLogger(MariaDbStatement.class);

  static {
    mapper.put("\u0000", "\\0");
    mapper.put("'", "\\\\'");
    mapper.put("\"", "\\\\\"");
    mapper.put("\b", "\\\\b");
    mapper.put("\n", "\\\\n");
    mapper.put("\r", "\\\\r");
    mapper.put("\t", "\\\\t");
    mapper.put("\u001A", "\\\\Z");
    mapper.put("\\", "\\\\");
  }

  protected final ReentrantLock lock;
  protected final int resultSetScrollType;
  protected final int resultSetConcurrency;
  protected final Options options;
  protected final boolean canUseServerTimeout;
  /** the protocol used to talk to the server. */
  protected Protocol protocol;
  /** the Connection object. */
  protected MariaDbConnection connection;

  protected volatile boolean closed = false;
  protected int queryTimeout;
  protected long maxRows;
  protected Results results;
  protected int fetchSize;
  protected volatile boolean executing;
  protected ExceptionFactory exceptionFactory;
  private ScheduledExecutorService timeoutScheduler;
  // are warnings cleared?
  private boolean warningsCleared;
  private boolean mustCloseOnCompletion = false;
  private List<String> batchQueries;
  private Future<?> timerTaskFuture;
  private boolean isTimedout;
  private int maxFieldSize;
  private boolean escape = true;

  /**
   * Creates a new Statement.
   *
   * @param connection the connection to return in getConnection.
   * @param resultSetScrollType one of the following <code>ResultSet</code> constants: <code>
   *     ResultSet.TYPE_FORWARD_ONLY</code>, <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or
   *     <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
   * @param resultSetConcurrency a concurrency type; one of <code>ResultSet.CONCUR_READ_ONLY</code>
   *     or <code>ResultSet.CONCUR_UPDATABLE</code>
   * @param exceptionFactory exception factory
   */
  public MariaDbStatement(
      MariaDbConnection connection,
      int resultSetScrollType,
      int resultSetConcurrency,
      ExceptionFactory exceptionFactory) {
    this.protocol = connection.getProtocol();
    this.connection = connection;
    this.canUseServerTimeout = connection.canUseServerTimeout();
    this.resultSetScrollType = resultSetScrollType;
    this.resultSetConcurrency = resultSetConcurrency;
    this.lock = this.connection.lock;
    this.options = this.protocol.getOptions();
    this.exceptionFactory = exceptionFactory;
    this.fetchSize = this.options.defaultFetchSize;
  }

  /**
   * Clone statement.
   *
   * @param connection connection
   * @return Clone statement.
   * @throws CloneNotSupportedException if any error occur.
   */
  public MariaDbStatement clone(MariaDbConnection connection) throws CloneNotSupportedException {
    MariaDbStatement clone = (MariaDbStatement) super.clone();
    clone.connection = connection;
    clone.protocol = connection.getProtocol();
    clone.timerTaskFuture = null;
    clone.batchQueries = new ArrayList<>();
    clone.closed = false;
    clone.warningsCleared = true;
    clone.maxRows = 0;
    clone.fetchSize = this.options.defaultFetchSize;
    clone.exceptionFactory =
        ExceptionFactory.of(
            this.exceptionFactory.getThreadId(), this.exceptionFactory.getOptions());
    return clone;
  }

  // Part of query prolog - setup timeout timer
  protected void setTimerTask(boolean isBatch) {
    assert (timerTaskFuture == null);
    if (timeoutScheduler == null) {
      timeoutScheduler = SchedulerServiceProviderHolder.getTimeoutScheduler();
    }
    timerTaskFuture =
        timeoutScheduler.schedule(
            () -> {
              try {
                isTimedout = true;
                if (!isBatch) {
                  protocol.cancelCurrentQuery();
                }
                protocol.interrupt();
              } catch (Throwable e) {
                // eat
              }
            },
            queryTimeout,
            TimeUnit.SECONDS);
  }

  /**
   * Command prolog.
   *
   * <ol>
   *   <li>clear previous query state
   *   <li>launch timeout timer if needed
   * </ol>
   *
   * @param isBatch is batch
   * @throws SQLException if statement is closed
   */
  protected void executeQueryPrologue(boolean isBatch) throws SQLException {
    executing = true;
    if (closed) {
      throw exceptionFactory
          .raiseStatementError(connection, this)
          .create("execute() is called on closed statement");
    }
    protocol.prolog(maxRows, protocol.getProxy() != null, connection, this);
    if (queryTimeout != 0 && (!canUseServerTimeout || isBatch)) {
      setTimerTask(isBatch);
    }
  }

  private void stopTimeoutTask() {
    if (timerTaskFuture != null) {
      if (!timerTaskFuture.cancel(true)) {
        // could not cancel, task either started or already finished
        // we must now wait for task to finish to ensure state modifications are done
        try {
          timerTaskFuture.get();
        } catch (InterruptedException e) {
          // reset interrupt status
          Thread.currentThread().interrupt();
        } catch (ExecutionException e) {
          // ignore error, likely due to interrupting during cancel
        }
        // we don't catch the exception if already canceled, that would indicate we tried
        // to cancel in parallel (which this code currently is not designed for)
      }
      timerTaskFuture = null;
    }
  }

  /**
   * Reset timeout after query, re-throw SQL exception.
   *
   * @param sqle current exception
   * @return SQLException exception with new message in case of timer timeout.
   */
  protected SQLException executeExceptionEpilogue(SQLException sqle) {
    // if has a failover, closing the statement
    if (sqle.getSQLState() != null && sqle.getSQLState().startsWith("08")) {
      try {
        close();
      } catch (SQLException sqlee) {
        // eat exception
      }
    }

    if (sqle.getErrorCode() == 1148 && !options.allowLocalInfile) {
      return exceptionFactory
          .raiseStatementError(connection, this)
          .create(
              "Usage of LOCAL INFILE is disabled. "
                  + "To use it enable it via the connection property allowLocalInfile=true",
              "42000",
              1148,
              sqle);
    }

    if (isTimedout) {
      return exceptionFactory
          .raiseStatementError(connection, this)
          .create("Query timed out", "70100", 1317, sqle);
    }

    SQLException sqlException = exceptionFactory.raiseStatementError(connection, this).create(sqle);
    logger.error("error executing query", sqlException);
    return sqlException;
  }

  protected void executeEpilogue() {
    stopTimeoutTask();
    isTimedout = false;
    executing = false;
  }

  protected void executeBatchEpilogue() {
    executing = false;
    stopTimeoutTask();
    isTimedout = false;
    clearBatch();
  }

  private SQLException handleFailoverAndTimeout(SQLException sqle) {

    // if has a failover, closing the statement
    if (sqle.getSQLState() != null && sqle.getSQLState().startsWith("08")) {
      try {
        close();
      } catch (SQLException sqlee) {
        // eat exception
      }
    }

    if (isTimedout) {
      return exceptionFactory
          .raiseStatementError(connection, this)
          .create("Query timed out", "70100", 1317, sqle);
    }
    return sqle;
  }

  protected BatchUpdateException executeBatchExceptionEpilogue(SQLException initialSqle, int size) {
    SQLException sqle = handleFailoverAndTimeout(initialSqle);
    int[] ret;
    if (results == null || !results.commandEnd()) {
      ret = new int[size];
      Arrays.fill(ret, Statement.EXECUTE_FAILED);
    } else {
      ret = results.getCmdInformation().getUpdateCounts();
    }
    sqle = exceptionFactory.raiseStatementError(connection, this).create(sqle);
    logger.error("error executing query", sqle);

    return new BatchUpdateException(
        sqle.getMessage(), sqle.getSQLState(), sqle.getErrorCode(), ret, sqle);
  }

  /**
   * Executes a query.
   *
   * @param sql the query
   * @param fetchSize fetch size
   * @param autoGeneratedKeys a flag indicating whether auto-generated keys should be returned; one
   *     of <code>Statement.RETURN_GENERATED_KEYS</code> or <code>Statement.NO_GENERATED_KEYS</code>
   * @return true if there was a result set, false otherwise.
   * @throws SQLException the error description
   */
  private boolean executeInternal(String sql, int fetchSize, int autoGeneratedKeys)
      throws SQLException {

    lock.lock();
    try {

      executeQueryPrologue(false);
      results =
          new Results(
              this,
              fetchSize,
              false,
              1,
              false,
              resultSetScrollType,
              resultSetConcurrency,
              autoGeneratedKeys,
              protocol.getAutoIncrementIncrement(),
              sql,
              null);
      protocol.executeQuery(
          protocol.isMasterConnection(), results, getTimeoutSql(nativeSql(sql, protocol)));
      results.commandEnd();
      return results.getResultSet() != null;

    } catch (SQLException exception) {
      throw executeExceptionEpilogue(exception);
    } finally {
      executeEpilogue();
      lock.unlock();
    }
  }

  /**
   * Enquote String value.
   *
   * @param val string value to enquote
   * @return enquoted string value
   * @throws SQLException -not possible-
   */
  public String enquoteLiteral(String val) throws SQLException {

    Matcher matcher = escapePattern.matcher(val);
    StringBuffer escapedVal = new StringBuffer("'");

    while (matcher.find()) {
      matcher.appendReplacement(escapedVal, mapper.get(matcher.group()));
    }
    matcher.appendTail(escapedVal);
    escapedVal.append("'");
    return escapedVal.toString();
  }

  /**
   * Escaped identifier according to MariaDB requirement.
   *
   * @param identifier identifier
   * @param alwaysQuote indicate if identifier must be enquoted even if not necessary.
   * @return return escaped identifier, quoted when necessary or indicated with alwaysQuote.
   * @see <a href="https://mariadb.com/kb/en/library/identifier-names/">mariadb identifier name</a>
   * @throws SQLException if containing u0000 character
   */
  public String enquoteIdentifier(String identifier, boolean alwaysQuote) throws SQLException {
    if (isSimpleIdentifier(identifier)) {
      return alwaysQuote ? "`" + identifier + "`" : identifier;
    } else {
      if (identifier.contains("\u0000")) {
        throw exceptionFactory
            .raiseStatementError(connection, this)
            .create("Invalid name - containing u0000 character", "42000");
      }

      if (identifier.matches("^`.+`$")) {
        identifier = identifier.substring(1, identifier.length() - 1);
      }
      return "`" + identifier.replace("`", "``") + "`";
    }
  }

  /**
   * Retrieves whether identifier is a simple SQL identifier. The first character is an alphabetic
   * character from a through z, or from A through Z The string only contains alphanumeric
   * characters or the characters "_" and "$"
   *
   * @param identifier identifier
   * @return true if identifier doesn't have to be quoted
   * @see <a href="https://mariadb.com/kb/en/library/identifier-names/">mariadb identifier name</a>
   * @throws SQLException exception
   */
  public boolean isSimpleIdentifier(String identifier) throws SQLException {
    return identifier != null
        && !identifier.isEmpty()
        && identifierPattern.matcher(identifier).matches();
  }

  /**
   * Enquote utf8 value.
   *
   * @param val value to enquote
   * @return enquoted String value
   * @throws SQLException - not possible -
   */
  public String enquoteNCharLiteral(String val) throws SQLException {
    return "N'" + val.replace("'", "''") + "'";
  }

  private String getTimeoutSql(String sql) {
    if (queryTimeout != 0 && canUseServerTimeout) {
      return "SET STATEMENT max_statement_time=" + queryTimeout + " FOR " + sql;
    }
    return sql;
  }

  private String nativeSql(String sql, Protocol protocol) throws SQLException {
    return escape ? Utils.nativeSql(sql, protocol) : sql;
  }

  /**
   * ! This method is for test only ! This permit sending query using specific charset.
   *
   * @param sql sql
   * @param charset charset
   * @return boolean if execution went well
   * @throws SQLException if any exception occur
   */
  public boolean testExecute(String sql, Charset charset) throws SQLException {
    lock.lock();
    try {

      executeQueryPrologue(false);
      results =
          new Results(
              this,
              fetchSize,
              false,
              1,
              false,
              resultSetScrollType,
              resultSetConcurrency,
              Statement.NO_GENERATED_KEYS,
              protocol.getAutoIncrementIncrement(),
              sql,
              null);
      protocol.executeQuery(
          protocol.isMasterConnection(), results, getTimeoutSql(nativeSql(sql, protocol)), charset);
      results.commandEnd();
      return results.getResultSet() != null;

    } catch (SQLException exception) {
      throw executeExceptionEpilogue(exception);
    } finally {
      executeEpilogue();
      lock.unlock();
    }
  }

  /**
   * executes a query.
   *
   * @param sql the query
   * @return true if there was a result set, false otherwise.
   * @throws SQLException if the query could not be sent to server
   */
  public boolean execute(String sql) throws SQLException {
    return executeInternal(sql, fetchSize, Statement.NO_GENERATED_KEYS);
  }

  /**
   * Executes the given SQL statement, which may return multiple results, and signals the driver
   * that any auto-generated keys should be made available for retrieval. The driver will ignore
   * this signal if the SQL statement is not an <code>INSERT</code> statement, or an SQL statement
   * able to return auto-generated keys (the list of such statements is vendor-specific).
   *
   * <p>In some (uncommon) situations, a single SQL statement may return multiple result sets and/or
   * update counts. Normally you can ignore this unless you are (1) executing a stored procedure
   * that you know may return multiple results or (2) you are dynamically executing an unknown SQL
   * string. The <code>execute</code> method executes an SQL statement and indicates the form of the
   * first result. You must then use the methods <code>getResultSet</code> or <code>getUpdateCount
   * </code> to retrieve the result, and <code>getInternalMoreResults</code> to move to any
   * subsequent result(s).
   *
   * @param sql any SQL statement
   * @param autoGeneratedKeys a constant indicating whether auto-generated keys should be made
   *     available for retrieval using the method<code>getGeneratedKeys</code>; one of the following
   *     constants: <code>Statement.RETURN_GENERATED_KEYS</code> or <code>
   *     Statement.NO_GENERATED_KEYS</code>
   * @return <code>true</code> if the first result is a <code>ResultSet</code> object; <code>false
   *     </code> if it is an update count or there are no results
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the second parameter supplied to this method is not <code>
   *     Statement.RETURN_GENERATED_KEYS</code> or <code>Statement.NO_GENERATED_KEYS</code>.
   * @see #getResultSet
   * @see #getUpdateCount
   * @see #getMoreResults
   * @see #getGeneratedKeys
   */
  public boolean execute(final String sql, final int autoGeneratedKeys) throws SQLException {
    return executeInternal(sql, fetchSize, autoGeneratedKeys);
  }

  /**
   * Executes the given SQL statement, which may return multiple results, and signals the driver
   * that the auto-generated keys indicated in the given array should be made available for
   * retrieval. This array contains the indexes of the columns in the target table that contain the
   * auto-generated keys that should be made available. The driver will ignore the array if the SQL
   * statement is not an <code>INSERT</code> statement, or an SQL statement able to return
   * auto-generated keys (the list of such statements is vendor-specific).
   *
   * <p>Under some (uncommon) situations, a single SQL statement may return multiple result sets
   * and/or update counts. Normally you can ignore this unless you are (1) executing a stored
   * procedure that you know may return multiple results or (2) you are dynamically executing an
   * unknown SQL string. The <code>execute</code> method executes an SQL statement and indicates the
   * form of the first result. You must then use the methods <code>getResultSet</code> or <code>
   * getUpdateCount</code> to retrieve the result, and <code>getInternalMoreResults</code> to move
   * to any subsequent result(s).
   *
   * @param sql any SQL statement
   * @param columnIndexes an array of the indexes of the columns in the inserted row that should be
   *     made available for retrieval by a call to the method <code>getGeneratedKeys</code>
   * @return <code>true</code> if the first result is a <code>ResultSet</code> object; <code>false
   *     </code> if it is an update count or there are no results
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the elements in the <code>int</code> array passed to this method
   *     are not valid column indexes
   * @see #getResultSet
   * @see #getUpdateCount
   * @see #getMoreResults
   */
  public boolean execute(final String sql, final int[] columnIndexes) throws SQLException {
    return executeInternal(sql, fetchSize, Statement.RETURN_GENERATED_KEYS);
  }

  /**
   * Executes the given SQL statement, which may return multiple results, and signals the driver
   * that the auto-generated keys indicated in the given array should be made available for
   * retrieval. This array contains the names of the columns in the target table that contain the
   * auto-generated keys that should be made available. The driver will ignore the array if the SQL
   * statement is not an <code>INSERT</code> statement, or an SQL statement able to return
   * auto-generated keys (the list of such statements is vendor-specific).
   *
   * <p>In some (uncommon) situations, a single SQL statement may return multiple result sets and/or
   * update counts. Normally you can ignore this unless you are (1) executing a stored procedure
   * that you know may return multiple results or (2) you are dynamically executing an unknown SQL
   * string.
   *
   * <p>The <code>execute</code> method executes an SQL statement and indicates the form of the
   * first result. You must then use the methods <code>getResultSet</code> or <code>getUpdateCount
   * </code> to retrieve the result, and <code>getInternalMoreResults</code> to move to any
   * subsequent result(s).
   *
   * @param sql any SQL statement
   * @param columnNames an array of the names of the columns in the inserted row that should be made
   *     available for retrieval by a call to the method <code>getGeneratedKeys</code>
   * @return <code>true</code> if the next result is a <code>ResultSet</code> object; <code>false
   *     </code> if it is an update count or there are no more results
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the elements of the <code>String</code> array passed to this
   *     method are not valid column names
   * @see #getResultSet
   * @see #getUpdateCount
   * @see #getMoreResults
   * @see #getGeneratedKeys
   */
  public boolean execute(final String sql, final String[] columnNames) throws SQLException {
    return executeInternal(sql, fetchSize, Statement.RETURN_GENERATED_KEYS);
  }

  /**
   * executes a select query.
   *
   * @param sql the query to send to the server
   * @return a result set
   * @throws SQLException if something went wrong
   */
  public ResultSet executeQuery(String sql) throws SQLException {
    if (executeInternal(sql, fetchSize, Statement.NO_GENERATED_KEYS)) {
      return results.getResultSet();
    }
    return SelectResultSet.createEmptyResultSet();
  }

  /**
   * Executes an update. Result-set are permitted for historical reason, even if spec indicate to
   * throw exception.
   *
   * @param sql the update query.
   * @return update count
   * @throws SQLException if the query could not be sent to server.
   */
  public int executeUpdate(String sql) throws SQLException {
    if (executeInternal(sql, fetchSize, Statement.NO_GENERATED_KEYS)) {
      return 0;
    }
    return getUpdateCount();
  }

  /**
   * Executes the given SQL statement and signals the driver with the given flag about whether the
   * auto-generated keys produced by this <code>Statement</code> object should be made available for
   * retrieval. The driver will ignore the flag if the SQL statement is not an <code>INSERT</code>
   * statement, or an SQL statement able to return auto-generated keys (the list of such statements
   * is vendor-specific). Result-set are permitted for historical reason, even if spec indicate to
   * throw exception.
   *
   * @param sql an SQL Data Manipulation Language (DML) statement, such as <code>INSERT</code>,
   *     <code>UPDATE</code> or <code>DELETE</code>; or an SQL statement that returns nothing, such
   *     as a DDL statement.
   * @param autoGeneratedKeys a flag indicating whether auto-generated keys should be made available
   *     for retrieval; one of the following constants: <code>Statement.RETURN_GENERATED_KEYS</code>
   *     <code>Statement.NO_GENERATED_KEYS</code>
   * @return either (1) the row count for SQL Data Manipulation Language (DML) statements or (2) 0
   *     for SQL statements that return nothing
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the given constant is not one of those allowed
   */
  public int executeUpdate(final String sql, final int autoGeneratedKeys) throws SQLException {
    if (executeInternal(sql, fetchSize, autoGeneratedKeys)) {
      return 0;
    }
    return getUpdateCount();
  }

  /**
   * Executes the given SQL statement and signals the driver that the auto-generated keys indicated
   * in the given array should be made available for retrieval. This array contains the indexes of
   * the columns in the target table that contain the auto-generated keys that should be made
   * available. The driver will ignore the array if the SQL statement is not an <code>INSERT</code>
   * statement, or an SQL statement able to return auto-generated keys (the list of such statements
   * is vendor-specific). Result-set are permitted for historical reason, even if spec indicate to
   * throw exception.
   *
   * @param sql an SQL Data Manipulation Language (DML) statement, such as <code>INSERT</code>,
   *     <code>UPDATE</code> or <code>DELETE</code>; or an SQL statement that returns nothing, such
   *     as a DDL statement.
   * @param columnIndexes an array of column indexes indicating the columns that should be returned
   *     from the inserted row
   * @return either (1) the row count for SQL Data Manipulation Language (DML) statements or (2) 0
   *     for SQL statements that return nothing
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the second argument supplied to this method is not an <code>int
   *     </code> array whose elements are valid column indexes
   */
  public int executeUpdate(final String sql, final int[] columnIndexes) throws SQLException {
    return executeUpdate(sql, Statement.RETURN_GENERATED_KEYS);
  }

  /**
   * Executes the given SQL statement and signals the driver that the auto-generated keys indicated
   * in the given array should be made available for retrieval. This array contains the names of the
   * columns in the target table that contain the auto-generated keys that should be made available.
   * The driver will ignore the array if the SQL statement is not an <code>INSERT</code> statement,
   * or an SQL statement able to return auto-generated keys (the list of such statements is
   * vendor-specific). Result-set are permitted for historical reason, even if spec indicate to
   * throw exception.
   *
   * @param sql an SQL Data Manipulation Language (DML) statement, such as <code>INSERT</code>,
   *     <code>UPDATE</code> or <code>DELETE</code>; or an SQL statement that returns nothing, such
   *     as a DDL statement.
   * @param columnNames an array of the names of the columns that should be returned from the
   *     inserted row
   * @return either the row count for <code>INSERT</code>, <code>UPDATE</code>, or <code>DELETE
   *     </code> statements, or 0 for SQL statements that return nothing
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the second argument supplied to this method is not a <code>String
   *     </code> array whose elements are valid column names
   */
  public int executeUpdate(final String sql, final String[] columnNames) throws SQLException {
    return executeUpdate(sql, Statement.RETURN_GENERATED_KEYS);
  }

  /**
   * Executes the given SQL statement, which may be an INSERT, UPDATE, or DELETE statement or an SQL
   * statement that returns nothing, such as an SQL DDL statement. This method should be used when
   * the returned row count may exceed Integer.MAX_VALUE.
   *
   * @param sql sql command
   * @return update counts
   * @throws SQLException if any error occur during execution
   */
  @Override
  public long executeLargeUpdate(String sql) throws SQLException {
    if (executeInternal(sql, fetchSize, Statement.NO_GENERATED_KEYS)) {
      return 0;
    }
    return getLargeUpdateCount();
  }

  /**
   * Identical to executeLargeUpdate(String sql), with a flag that indicate that autoGeneratedKeys
   * (primary key fields with "auto_increment") generated id's must be retrieved.
   *
   * <p>Those id's will be available using getGeneratedKeys() method.
   *
   * @param sql sql command
   * @param autoGeneratedKeys a flag indicating whether auto-generated keys should be made available
   *     for retrieval; one of the following constants: Statement.RETURN_GENERATED_KEYS
   *     Statement.NO_GENERATED_KEYS
   * @return update counts
   * @throws SQLException if any error occur during execution
   */
  @Override
  public long executeLargeUpdate(String sql, int autoGeneratedKeys) throws SQLException {
    if (executeInternal(sql, fetchSize, autoGeneratedKeys)) {
      return 0;
    }
    return getLargeUpdateCount();
  }

  /**
   * Identical to executeLargeUpdate(String sql, int autoGeneratedKeys) with autoGeneratedKeys =
   * Statement.RETURN_GENERATED_KEYS set.
   *
   * @param sql sql command
   * @param columnIndexes column Indexes
   * @return update counts
   * @throws SQLException if any error occur during execution
   */
  @Override
  public long executeLargeUpdate(String sql, int[] columnIndexes) throws SQLException {
    return executeLargeUpdate(sql, Statement.RETURN_GENERATED_KEYS);
  }

  /**
   * Identical to executeLargeUpdate(String sql, int autoGeneratedKeys) with autoGeneratedKeys =
   * Statement.RETURN_GENERATED_KEYS set.
   *
   * @param sql sql command
   * @param columnNames columns names
   * @return update counts
   * @throws SQLException if any error occur during execution
   */
  @Override
  public long executeLargeUpdate(String sql, String[] columnNames) throws SQLException {
    return executeLargeUpdate(sql, Statement.RETURN_GENERATED_KEYS);
  }

  /**
   * Releases this <code>Statement</code> object's database and JDBC resources immediately instead
   * of waiting for this to happen when it is automatically closed. It is generally good practice to
   * release resources as soon as you are finished with them to avoid tying up database resources.
   * Calling the method <code>close</code> on a <code>Statement</code> object that is already closed
   * has no effect. <B>Note:</B>When a <code>Statement</code> object is closed, its current <code>
   * ResultSet</code> object, if one exists, is also closed.
   *
   * @throws SQLException if a database access error occurs
   */
  public void close() throws SQLException {
    lock.lock();
    try {
      closed = true;
      if (results != null) {
        if (results.getFetchSize() != 0) {
          skipMoreResults();
        }

        results.close();
      }

      if (connection == null
          || connection.pooledConnection == null
          || connection.pooledConnection.noStmtEventListeners()) {
        return;
      }
      connection.pooledConnection.fireStatementClosed(this);
    } finally {
      protocol = null;
      connection = null;
      lock.unlock();
    }
  }

  /**
   * Retrieves the maximum number of bytes that can be returned for character and binary column
   * values in a <code>ResultSet</code> object produced by this <code>Statement</code> object. This
   * limit applies only to <code>BINARY</code>, <code>VARBINARY</code>, <code>LONGVARBINARY</code>,
   * <code>CHAR</code>, <code>VARCHAR</code>, <code>NCHAR</code>, <code>NVARCHAR</code>, <code>
   * LONGNVARCHAR</code> and <code>LONGVARCHAR</code> columns. If the limit is exceeded, the excess
   * data is silently discarded.
   *
   * @return the current column size limit for columns storing character and binary values; zero
   *     means there is no limit
   * @see #setMaxFieldSize
   */
  public int getMaxFieldSize() {
    return maxFieldSize;
  }

  /**
   * Sets the limit for the maximum number of bytes that can be returned for character and binary
   * column values in a <code>ResultSet</code> object produced by this <code>Statement</code>
   * object. This limit applies only to <code>BINARY</code>, <code>VARBINARY</code>, <code>
   * LONGVARBINARY</code>, <code>CHAR</code>, <code>VARCHAR</code>, <code>NCHAR</code>, <code>
   * NVARCHAR</code>, <code>LONGNVARCHAR</code> and <code>LONGVARCHAR</code> fields. If the limit is
   * exceeded, the excess data is silently discarded. For maximum portability, use values greater
   * than 256.
   *
   * @param max the new column size limit in bytes; zero means there is no limit
   * @see #getMaxFieldSize
   */
  public void setMaxFieldSize(final int max) {
    maxFieldSize = max;
  }

  /**
   * Retrieves the maximum number of rows that a <code>ResultSet</code> object produced by this
   * <code>Statement</code> object can contain. If this limit is exceeded, the excess rows are
   * silently dropped.
   *
   * @return the current maximum number of rows for a <code>ResultSet</code> object produced by this
   *     <code>Statement</code> object; zero means there is no limit
   * @see #setMaxRows
   */
  public int getMaxRows() {
    return (int) maxRows;
  }

  /**
   * Sets the limit for the maximum number of rows that any <code>ResultSet</code> object generated
   * by this <code>Statement</code> object can contain to the given number. If the limit is
   * exceeded, the excess rows are silently dropped.
   *
   * @param max the new max rows limit; zero means there is no limit
   * @throws SQLException if the condition max &gt;= 0 is not satisfied
   * @see #getMaxRows
   */
  public void setMaxRows(final int max) throws SQLException {
    if (max < 0) {
      throw exceptionFactory
          .raiseStatementError(connection, this)
          .create("max rows cannot be negative : asked for " + max, "42000");
    }
    maxRows = max;
  }

  /**
   * Retrieves the maximum number of rows that a ResultSet object produced by this Statement object
   * can contain. If this limit is exceeded, the excess rows are silently dropped.
   *
   * @return the current maximum number of rows for a ResultSet object produced by this Statement
   *     object; zero means there is no limit
   */
  @Override
  public long getLargeMaxRows() {
    return maxRows;
  }

  /**
   * Sets the limit for the maximum number of rows that any ResultSet object generated by this
   * Statement object can contain to the given number. If the limit is exceeded, the excess rows are
   * silently dropped.
   *
   * @param max the new max rows limit; zero means there is no limit
   * @throws SQLException if the condition max &gt;= 0 is not satisfied
   */
  @Override
  public void setLargeMaxRows(long max) throws SQLException {
    if (max < 0) {
      throw exceptionFactory
          .raiseStatementError(connection, this)
          .create("max rows cannot be negative : setLargeMaxRows value is " + max, "42000");
    }
    maxRows = max;
  }

  /**
   * Sets escape processing on or off. If escape scanning is on (the default), the driver will do
   * escape substitution before sending the SQL statement to the database. Note: Since prepared
   * statements have usually been parsed prior to making this call, disabling escape processing for
   * <code>PreparedStatements</code> objects will have no effect.
   *
   * @param enable <code>true</code> to enable escape processing; <code>false</code> to disable it
   */
  public void setEscapeProcessing(final boolean enable) {
    escape = enable;
  }

  /**
   * Retrieves the number of seconds the driver will wait for a <code>Statement</code> object to
   * execute. If the limit is exceeded, a <code>SQLException</code> is thrown.
   *
   * @return the current query timeout limit in seconds; zero means there is no limit
   * @see #setQueryTimeout
   */
  public int getQueryTimeout() {
    return queryTimeout;
  }

  /**
   * Sets the number of seconds the driver will wait for a <code>Statement</code> object to execute
   * to the given number of seconds. If the limit is exceeded, an <code>SQLException</code> is
   * thrown. A JDBC driver must apply this limit to the <code>execute</code>, <code>executeQuery
   * </code> and <code>executeUpdate</code> methods.
   *
   * @param seconds the new query timeout limit in seconds; zero means there is no limit
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the condition seconds &gt;= 0 is not satisfied
   * @see #getQueryTimeout
   */
  public void setQueryTimeout(final int seconds) throws SQLException {
    if (seconds < 0) {
      throw exceptionFactory
          .raiseStatementError(connection, this)
          .create("Query timeout cannot be negative : asked for " + seconds, "42000");
    }
    this.queryTimeout = seconds;
  }

  /**
   * Sets the inputStream that will be used for the next execute that uses "LOAD DATA LOCAL INFILE".
   * The name specified as local file/URL will be ignored.
   *
   * @param inputStream inputStream instance, that will be used to send data to server
   * @throws SQLException if statement is closed
   */
  public void setLocalInfileInputStream(InputStream inputStream) throws SQLException {
    checkClose();
    protocol.setLocalInfileInputStream(inputStream);
  }

  /**
   * Cancels this <code>Statement</code> object if both the DBMS and driver support aborting an SQL
   * statement. This method can be used by one thread to cancel a statement that is being executed
   * by another thread.
   *
   * <p>In case there is result-set from this Statement that are still streaming data from server,
   * will cancel streaming.
   *
   * @throws SQLException if a database access error occurs or this method is called on a closed
   *     <code>Statement</code>
   */
  public void cancel() throws SQLException {
    checkClose();
    boolean locked = lock.tryLock();
    try {
      if (executing) {
        protocol.cancelCurrentQuery();
      } else if (results != null
          && results.getFetchSize() != 0
          && !results.isFullyLoaded(protocol)) {
        try {
          protocol.cancelCurrentQuery();
          skipMoreResults();
        } catch (SQLException e) {
          // eat exception
        }
        results.removeFetchSize();
      }

    } catch (SQLException e) {
      logger.error("error cancelling query", e);
      throw exceptionFactory.raiseStatementError(connection, this).create(e);
    } finally {
      if (locked) {
        lock.unlock();
      }
    }
  }

  /**
   * Retrieves the first warning reported by calls on this <code>Statement</code> object. Subsequent
   * <code>Statement</code> object warnings will be chained to this <code>SQLWarning</code> object.
   *
   * <p>The warning chain is automatically cleared each time a statement is (re)executed. This
   * method may not be called on a closed <code>Statement</code> object; doing so will cause an
   * <code>SQLException</code> to be thrown.
   *
   * <p><B>Note:</B> If you are processing a <code>ResultSet</code> object, any warnings associated
   * with reads on that <code>ResultSet</code> object will be chained on it rather than on the
   * <code>Statement</code> object that produced it.
   *
   * @return the first <code>SQLWarning</code> object or <code>null</code> if there are no warnings
   * @throws SQLException if a database access error occurs or this method is called on a closed
   *     <code>Statement</code>
   */
  public SQLWarning getWarnings() throws SQLException {
    checkClose();
    if (!warningsCleared) {
      return this.connection.getWarnings();
    }
    return null;
  }

  /**
   * Clears all the warnings reported on this <code>Statement</code> object. After a call to this
   * method, the method <code>getWarnings</code> will return <code>null</code> until a new warning
   * is reported for this <code>Statement</code> object.
   */
  public void clearWarnings() {
    warningsCleared = true;
  }

  /**
   * Sets the SQL cursor name to the given <code>String</code>, which will be used by subsequent
   * <code>Statement</code> object <code>execute</code> methods. This name can then be used in SQL
   * positioned update or delete statements to identify the current row in the <code>ResultSet
   * </code> object generated by this statement. If the database does not support positioned
   * update/delete, this method is a noop. To insure that a cursor has the proper isolation level to
   * support updates, the cursor's <code>SELECT</code> statement should have the form <code>
   * SELECT FOR UPDATE</code>. If <code>FOR UPDATE</code> is not present, positioned updates may
   * fail.
   *
   * <p><B>Note:</B> By definition, the execution of positioned updates and deletes must be done by
   * a different <code>Statement</code> object than the one that generated the <code>ResultSet
   * </code> object being used for positioning. Also, cursor names must be unique within a
   * connection.
   *
   * @param name the new cursor name, which must be unique within a connection
   * @throws SQLException if a database access error occurs or this method is called on a closed
   *     <code>Statement</code>
   */
  public void setCursorName(final String name) throws SQLException {
    throw exceptionFactory
        .raiseStatementError(connection, this)
        .notSupported("Cursors are not supported");
  }

  /**
   * Gets the connection that created this statement.
   *
   * @return the connection
   */
  public MariaDbConnection getConnection() {
    return this.connection;
  }

  /**
   * Retrieves any auto-generated keys created as a result of executing this <code>Statement</code>
   * object. If this <code>Statement</code> object did not generate any keys, an empty <code>
   * ResultSet</code> object is returned.
   *
   * <p><B>Note:</B>If the columns which represent the auto-generated keys were not specified, the
   * JDBC driver implementation will determine the columns which best represent the auto-generated
   * keys.
   *
   * @return a <code>ResultSet</code> object containing the auto-generated key(s) generated by the
   *     execution of this <code>Statement</code> object
   * @throws SQLException if a database access error occurs or this method is called on a closed
   *     <code>Statement</code>
   */
  public ResultSet getGeneratedKeys() throws SQLException {
    if (results != null) {
      return results.getGeneratedKeys(protocol);
    }
    return SelectResultSet.createEmptyResultSet();
  }

  /**
   * Retrieves the result set holdability for <code>ResultSet</code> objects generated by this
   * <code>Statement</code> object.
   *
   * @return either <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or <code>
   *     ResultSet.CLOSE_CURSORS_AT_COMMIT</code>
   * @since 1.4
   */
  public int getResultSetHoldability() {
    return ResultSet.HOLD_CURSORS_OVER_COMMIT;
  }

  /**
   * Retrieves whether this <code>Statement</code> object has been closed. A <code>Statement</code>
   * is closed if the method close has been called on it, or if it is automatically closed.
   *
   * @return true if this <code>Statement</code> object is closed; false if it is still open
   * @since 1.6
   */
  public boolean isClosed() {
    return closed;
  }

  /**
   * Returns a value indicating whether the <code>Statement</code> is poolable or not.
   *
   * @return <code>true</code> if the <code>Statement</code> is poolable; <code>false</code>
   *     otherwise
   * @see Statement#setPoolable(boolean) setPoolable(boolean)
   * @since 1.6
   */
  @Override
  public boolean isPoolable() {
    return false;
  }

  /**
   * Requests that a <code>Statement</code> be pooled or not pooled. The value specified is a hint
   * to the statement pool implementation indicating whether the applicaiton wants the statement to
   * be pooled. It is up to the statement pool manager as to whether the hint is used.
   *
   * <p>The poolable value of a statement is applicable to both internal statement caches
   * implemented by the driver and external statement caches implemented by application servers and
   * other applications.
   *
   * <p>By default, a <code>Statement</code> is not poolable when created, and a <code>
   * PreparedStatement</code> and <code>CallableStatement</code> are poolable when created.
   *
   * @param poolable requests that the statement be pooled if true and that the statement not be
   *     pooled if false
   * @since 1.6
   */
  @Override
  public void setPoolable(final boolean poolable) {
    // not handled
  }

  /**
   * Retrieves the current result as a ResultSet object. This method should be called only once per
   * result.
   *
   * @return the current result as a ResultSet object or null if the result is an update count or
   *     there are no more results
   * @throws SQLException if a database access error occurs or this method is called on a closed
   *     Statement
   */
  public ResultSet getResultSet() throws SQLException {
    checkClose();
    return results != null ? results.getResultSet() : null;
  }

  /**
   * Retrieves the current result as an update count; if the result is a ResultSet object or there
   * are no more results, -1 is returned. This method should be called only once per result.
   *
   * @return the current result as an update count; -1 if the current result is a ResultSet object
   *     or there are no more results
   */
  public int getUpdateCount() {
    if (results != null && results.getCmdInformation() != null && !results.isBatch()) {
      return results.getCmdInformation().getUpdateCount();
    }
    return -1;
  }

  /**
   * Retrieves the current result as an update count; if the result is a ResultSet object or there
   * are no more results, -1 is returned.
   *
   * @return last update count
   */
  @Override
  public long getLargeUpdateCount() {
    if (results != null && results.getCmdInformation() != null && !results.isBatch()) {
      return results.getCmdInformation().getLargeUpdateCount();
    }
    return -1;
  }

  protected void skipMoreResults() throws SQLException {
    try {
      protocol.skip();
      warningsCleared = false;
      connection.reenableWarnings();
    } catch (SQLException e) {
      logger.debug("error skipMoreResults", e);
      throw exceptionFactory.raiseStatementError(connection, this).create(e);
    }
  }

  /**
   * Moves to this <code>Statement</code> object's next result, returns <code>true</code> if it is a
   * <code>ResultSet</code> object, and implicitly closes any current <code>ResultSet</code>
   * object(s) obtained with the method <code>getResultSet</code>. There are no more results when
   * the following is true:
   *
   * <pre> // stmt is a Statement object
   * ((stmt.getInternalMoreResults() == false) &amp;&amp; (stmt.getUpdateCount() == -1)) </pre>
   *
   * @return <code>true</code> if the next result is a <code>ResultSet</code> object; <code>false
   *     </code> if it is an update count or there are no more results
   * @throws SQLException if a database access error occurs or this method is called on a closed
   *     <code>Statement</code>
   * @see #execute
   */
  public boolean getMoreResults() throws SQLException {
    return getMoreResults(Statement.CLOSE_CURRENT_RESULT);
  }

  /**
   * Moves to this <code>Statement</code> object's next result, deals with any current <code>
   * ResultSet</code> object(s) according to the instructions specified by the given flag, and
   * returns <code>true</code> if the next result is a <code>ResultSet</code> object. There are no
   * more results when the following is true:
   *
   * <pre> // stmt is a Statement object
   * ((stmt.getInternalMoreResults(current) == false) &amp;&amp; (stmt.getUpdateCount() == -1))
   * </pre>
   *
   * @param current one of the following <code>Statement</code> constants indicating what should
   *     happen to current <code>ResultSet</code> objects obtained using the method <code>
   *     getResultSet</code>: <code>Statement.CLOSE_CURRENT_RESULT</code>, <code>
   *     Statement.KEEP_CURRENT_RESULT</code>, or <code>Statement.CLOSE_ALL_RESULTS</code>
   * @return <code>true</code> if the next result is a <code>ResultSet</code> object; <code>false
   *     </code> if it is an update count or there are no more results
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the argument supplied is not one of the following: <code>
   *     Statement.CLOSE_CURRENT_RESULT</code>, <code>Statement.KEEP_CURRENT_RESULT</code> or <code>
   *     Statement.CLOSE_ALL_RESULTS</code>
   * @see #execute
   */
  public boolean getMoreResults(final int current) throws SQLException {
    // if fetch size is set to read fully, other resultSet are put in cache
    checkClose();
    return results != null && results.getMoreResults(current, protocol);
  }

  /**
   * Retrieves the direction for fetching rows from database tables that is the default for result
   * sets generated from this <code>Statement</code> object. If this <code>Statement</code> object
   * has not set a fetch direction by calling the method <code>setFetchDirection</code>, the return
   * value is implementation-specific.
   *
   * @return the default fetch direction for result sets generated from this <code>Statement</code>
   *     object
   * @see #setFetchDirection
   * @since 1.2
   */
  public int getFetchDirection() {
    return ResultSet.FETCH_FORWARD;
  }

  /**
   * Gives the driver a hint as to the direction in which rows will be processed in <code>ResultSet
   * </code> objects created using this <code>Statement</code> object. The default value is <code>
   * ResultSet.FETCH_FORWARD</code>.
   *
   * <p>Note that this method sets the default fetch direction for result sets generated by this
   * <code>Statement</code> object. Each result set has its own methods for getting and setting its
   * own fetch direction.
   *
   * @param direction the initial direction for processing rows
   * @see #getFetchDirection
   * @since 1.2
   */
  public void setFetchDirection(final int direction) {
    // not implemented
  }

  /**
   * Retrieves the number of result set rows that is the default fetch size for <code>ResultSet
   * </code> objects generated from this <code>Statement</code> object. If this <code>Statement
   * </code> object has not set a fetch size by calling the method <code>setFetchSize</code>, the
   * return value is implementation-specific.
   *
   * @return the default fetch size for result sets generated from this <code>Statement</code>
   *     object
   * @see #setFetchSize
   */
  public int getFetchSize() {
    return this.fetchSize;
  }

  /**
   * Gives the JDBC driver a hint as to the number of rows that should be fetched from the database
   * when more rows are needed for <code>ResultSet</code> objects generated by this <code>Statement
   * </code>. If the value specified is zero, then the hint is ignored. The default value is zero.
   *
   * @param rows the number of rows to fetch
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the condition <code>rows &gt;= 0</code> is not satisfied.
   * @see #getFetchSize
   */
  public void setFetchSize(final int rows) throws SQLException {
    if (rows < 0 && rows != Integer.MIN_VALUE) {
      throw exceptionFactory.raiseStatementError(connection, this).create("invalid fetch size");
    } else if (rows == Integer.MIN_VALUE) {
      // for compatibility Integer.MIN_VALUE is transform to 0 => streaming
      this.fetchSize = 1;
      return;
    }
    this.fetchSize = rows;
  }

  /**
   * Retrieves the result set concurrency for <code>ResultSet</code> objects generated by this
   * <code>Statement</code> object.
   *
   * @return either <code>ResultSet.CONCUR_READ_ONLY</code> or <code>ResultSet.CONCUR_UPDATABLE
   *     </code>
   * @since 1.2
   */
  public int getResultSetConcurrency() {
    return resultSetConcurrency;
  }

  /**
   * Retrieves the result set type for <code>ResultSet</code> objects generated by this <code>
   * Statement</code> object.
   *
   * @return one of <code>ResultSet.TYPE_FORWARD_ONLY</code>, <code>
   *     ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
   */
  public int getResultSetType() {
    return resultSetScrollType;
  }

  /**
   * Adds the given SQL command to the current list of commands for this <code>Statement</code>
   * object. The send in this list can be executed as a batch by calling the method <code>
   * executeBatch</code>.
   *
   * @param sql typically this is a SQL <code>INSERT</code> or <code>UPDATE</code> statement
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the driver does not support batch updates
   * @see #executeBatch
   * @see DatabaseMetaData#supportsBatchUpdates
   */
  public void addBatch(final String sql) throws SQLException {
    if (batchQueries == null) {
      batchQueries = new ArrayList<>();
    }
    if (sql == null) {
      throw exceptionFactory
          .raiseStatementError(connection, this)
          .create("null cannot be set to addBatch( String sql)");
    }
    batchQueries.add(sql);
  }

  /**
   * Empties this <code>Statement</code> object's current list of SQL send.
   *
   * @see #addBatch
   * @see DatabaseMetaData#supportsBatchUpdates
   * @since 1.2
   */
  public void clearBatch() {
    if (batchQueries != null) {
      batchQueries.clear();
    }
  }

  /**
   * Execute statements. depending on option, queries mays be rewritten :
   *
   * <p>those queries will be rewritten if possible to INSERT INTO ... VALUES (...) ; INSERT INTO
   * ... VALUES (...);
   *
   * <p>if option rewriteBatchedStatements is set to true, rewritten to INSERT INTO ... VALUES
   * (...), (...);
   *
   * @return an array of update counts containing one element for each command in the batch. The
   *     elements of the array are ordered according to the order in which send were added to the
   *     batch.
   * @throws SQLException if a database access error occurs, this method is called on a closed
   *     <code>Statement</code> or the driver does not support batch statements. Throws {@link
   *     BatchUpdateException} (a subclass of <code>SQLException</code>) if one of the send sent to
   *     the database fails to execute properly or attempts to return a result set.
   * @see #addBatch
   * @see DatabaseMetaData#supportsBatchUpdates
   * @since 1.3
   */
  public int[] executeBatch() throws SQLException {
    checkClose();
    int size;
    if (batchQueries == null || (size = batchQueries.size()) == 0) {
      return new int[0];
    }

    lock.lock();
    try {
      internalBatchExecution(size);
      return results.getCmdInformation().getUpdateCounts();
    } catch (SQLException initialSqlEx) {
      throw executeBatchExceptionEpilogue(initialSqlEx, size);
    } finally {
      executeBatchEpilogue();
      lock.unlock();
    }
  }

  /**
   * Execute batch, like executeBatch(), with returning results with long[]. For when row count may
   * exceed Integer.MAX_VALUE.
   *
   * @return an array of update counts (one element for each command in the batch)
   * @throws SQLException if a database error occur.
   */
  @Override
  public long[] executeLargeBatch() throws SQLException {
    checkClose();
    int size;
    if (batchQueries == null || (size = batchQueries.size()) == 0) {
      return new long[0];
    }

    lock.lock();
    try {
      internalBatchExecution(size);
      return results.getCmdInformation().getLargeUpdateCounts();

    } catch (SQLException initialSqlEx) {
      throw executeBatchExceptionEpilogue(initialSqlEx, size);
    } finally {
      executeBatchEpilogue();
      lock.unlock();
    }
  }

  /**
   * Internal batch execution.
   *
   * @param size expected result-set size
   * @throws SQLException throw exception if batch error occur
   */
  private void internalBatchExecution(int size) throws SQLException {

    executeQueryPrologue(true);
    results =
        new Results(
            this,
            0,
            true,
            size,
            false,
            resultSetScrollType,
            resultSetConcurrency,
            Statement.RETURN_GENERATED_KEYS,
            protocol.getAutoIncrementIncrement(),
            null,
            null);
    protocol.executeBatchStmt(protocol.isMasterConnection(), results, batchQueries);
    results.commandEnd();
  }

  /**
   * Returns an object that implements the given interface to allow access to non-standard methods,
   * or standard methods not exposed by the proxy.
   *
   * <p>If the receiver implements the interface then the result is the receiver or a proxy for the
   * receiver. If the receiver is a wrapper and the wrapped object implements the interface then the
   * result is the wrapped object or a proxy for the wrapped object. Otherwise return the the result
   * of calling <code>unwrap</code> recursively on the wrapped object or a proxy for that result. If
   * the receiver is not a wrapper and does not implement the interface, then an <code>SQLException
   * </code> is thrown.
   *
   * @param iface A Class defining an interface that the result must implement.
   * @return an object that implements the interface. May be a proxy for the actual implementing
   *     object.
   * @throws SQLException If no object found that implements the interface
   * @since 1.6
   */
  @SuppressWarnings("unchecked")
  public <T> T unwrap(final Class<T> iface) throws SQLException {
    try {
      if (isWrapperFor(iface)) {
        return (T) this;
      } else {
        throw exceptionFactory
            .raiseStatementError(connection, this)
            .create("The receiver is not a wrapper and does not implement the interface", "42000");
      }
    } catch (Exception e) {
      throw exceptionFactory
          .raiseStatementError(connection, this)
          .create("The receiver is not a wrapper and does not implement the interface", "42000");
    }
  }

  /**
   * Returns true if this either implements the interface argument or is directly or indirectly a
   * wrapper for an object that does. Returns false otherwise. If this implements the interface then
   * return true, else if this is a wrapper then return the result of recursively calling <code>
   * isWrapperFor</code> on the wrapped object. If this does not implement the interface and is not
   * a wrapper, return false. This method should be implemented as a low-cost operation compared to
   * <code>unwrap</code> so that callers can use this method to avoid expensive <code>unwrap</code>
   * calls that may fail. If this method returns true then calling <code>unwrap</code> with the same
   * argument should succeed.
   *
   * @param interfaceOrWrapper a Class defining an interface.
   * @return true if this implements the interface or directly or indirectly wraps an object that
   *     does.
   * @throws SQLException if an error occurs while determining whether this is a wrapper for an
   *     object with the given interface.
   * @since 1.6
   */
  public boolean isWrapperFor(final Class<?> interfaceOrWrapper) throws SQLException {
    return interfaceOrWrapper.isInstance(this);
  }

  public void closeOnCompletion() {
    mustCloseOnCompletion = true;
  }

  public boolean isCloseOnCompletion() {
    return mustCloseOnCompletion;
  }

  /**
   * Check that close on completion is asked, and close if so.
   *
   * @param resultSet resultSet
   * @throws SQLException if close has error
   */
  public void checkCloseOnCompletion(ResultSet resultSet) throws SQLException {
    if (mustCloseOnCompletion
        && !closed
        && results != null
        && resultSet.equals(results.getResultSet())) {
      close();
    }
  }

  /**
   * Check if statement is closed, and throw exception if so.
   *
   * @throws SQLException if statement close
   */
  protected void checkClose() throws SQLException {
    if (closed) {
      throw exceptionFactory
          .raiseStatementError(connection, this)
          .create("Cannot do an operation on a closed statement");
    }
  }
}
