/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.dialect.pagination;

import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.hibernate.engine.spi.RowSelection;
import org.hibernate.internal.util.StringHelper;

LIMIT clause handler compatible with SQL Server 2005 and later.
Author:
Lukasz Antoniak (lukasz dot antoniak at gmail dot com), Chris Cranford/**
 * LIMIT clause handler compatible with SQL Server 2005 and later.
 *
 * @author Lukasz Antoniak (lukasz dot antoniak at gmail dot com)
 * @author Chris Cranford
 */
public class SQLServer2005LimitHandler extends AbstractLimitHandler {
	private static final String SELECT = "select";
	private static final String FROM = "from";
	private static final String DISTINCT = "distinct";
	private static final String ORDER_BY = "order by";
	private static final String SELECT_DISTINCT = SELECT + " " + DISTINCT;
	private static final String SELECT_DISTINCT_SPACE = SELECT_DISTINCT + " ";

	final String SELECT_SPACE = "select ";

	private static final Pattern SELECT_DISTINCT_PATTERN = buildShallowIndexPattern( SELECT_DISTINCT_SPACE, true );
	private static final Pattern SELECT_PATTERN = buildShallowIndexPattern( SELECT + "(.*)", true );
	private static final Pattern FROM_PATTERN = buildShallowIndexPattern( FROM, true );
	private static final Pattern DISTINCT_PATTERN = buildShallowIndexPattern( DISTINCT, true );
	private static final Pattern ORDER_BY_PATTERN = buildShallowIndexPattern( ORDER_BY, true );
	private static final Pattern COMMA_PATTERN = buildShallowIndexPattern( ",", false );
	private static final Pattern ALIAS_PATTERN =
			Pattern.compile( "(?![^\\[]*(\\]))\\S+\\s*(\\s(?i)as\\s)\\s*(\\S+)*\\s*$|(?![^\\[]*(\\]))\\s+(\\S+)$" );

	// CTE pattern support
	private static final String SPACE_NEWLINE_LINEFEED = "[\\s\\t\\n\\r]*";
	private static final Pattern WITH_CTE = Pattern.compile( "(^" + SPACE_NEWLINE_LINEFEED + "WITH" + SPACE_NEWLINE_LINEFEED +")", Pattern.CASE_INSENSITIVE );
	private static final Pattern WITH_EXPRESSION_NAME = Pattern.compile( "(^" + SPACE_NEWLINE_LINEFEED + "[a-zA-Z0-9]*" + SPACE_NEWLINE_LINEFEED +")", Pattern.CASE_INSENSITIVE  );
	private static final Pattern WITH_COLUMN_NAMES_START = Pattern.compile( "(^" + SPACE_NEWLINE_LINEFEED + "\\()", Pattern.CASE_INSENSITIVE );
	private static final Pattern WITH_COLUMN_NAMES_END = Pattern.compile( "(\\))", Pattern.CASE_INSENSITIVE );
	private static final Pattern WITH_AS = Pattern.compile( "(^" + SPACE_NEWLINE_LINEFEED + "AS" + SPACE_NEWLINE_LINEFEED +")", Pattern.CASE_INSENSITIVE );
	private static final Pattern WITH_COMMA = Pattern.compile( "(^" + SPACE_NEWLINE_LINEFEED + ",)", Pattern.CASE_INSENSITIVE );

	// Flag indicating whether TOP(?) expression has been added to the original query.
	private boolean topAdded;
	private boolean isCTE;

	
Constructs a SQLServer2005LimitHandler
/**
	 * Constructs a SQLServer2005LimitHandler
	 */
	public SQLServer2005LimitHandler() {
		// NOP
	}

	@Override
	public boolean supportsLimit() {
		return true;
	}

	@Override
	public boolean useMaxForLimit() {
		return true;
	}

	@Override
	public boolean supportsLimitOffset() {
		return true;
	}

	@Override
	public boolean supportsVariableLimit() {
		return true;
	}

	@Override
	public int convertToFirstRowValue(int zeroBasedFirstResult) {
		// Our dialect paginated results aren't zero based. The first row should get the number 1 and so on
		return zeroBasedFirstResult + 1;
	}

	
Add a LIMIT clause to the given SQL SELECT (HHH-2655: ROW_NUMBER for Paging)
The LIMIT SQL will look like:
WITH query AS (
  SELECT inner_query.*
       , ROW_NUMBER() OVER (ORDER BY CURRENT_TIMESTAMP) as __hibernate_row_nr__
    FROM ( original_query_with_top_if_order_by_present_and_all_aliased_columns ) inner_query
)
SELECT alias_list FROM query WHERE __hibernate_row_nr__ >= offset AND __hibernate_row_nr__ < offset + last
 When offset equals 0, only TOP(?) expression is added to the original query.
Returns:
A new SQL statement with the LIMIT clause applied./**
	 * Add a LIMIT clause to the given SQL SELECT (HHH-2655: ROW_NUMBER for Paging)
	 *
	 * The LIMIT SQL will look like:
	 *
	 * <pre>
	 * WITH query AS (
	 *   SELECT inner_query.*
	 *        , ROW_NUMBER() OVER (ORDER BY CURRENT_TIMESTAMP) as __hibernate_row_nr__
	 *     FROM ( original_query_with_top_if_order_by_present_and_all_aliased_columns ) inner_query
	 * )
	 * SELECT alias_list FROM query WHERE __hibernate_row_nr__ >= offset AND __hibernate_row_nr__ < offset + last
	 * </pre>
	 *
	 * When offset equals {@literal 0}, only <code>TOP(?)</code> expression is added to the original query.
	 *
	 * @return A new SQL statement with the LIMIT clause applied.
	 */
	@Override
	public String processSql(String sql, RowSelection selection) {
		final StringBuilder sb = new StringBuilder( sql );
		if ( sb.charAt( sb.length() - 1 ) == ';' ) {
			sb.setLength( sb.length() - 1 );
		}

		// checks the query buffer for CTE queries or simple SELECT statements
		// returns the index where the injection should start.
		final int offset = getStatementIndex( sb );

		if ( !LimitHelper.hasFirstRow( selection ) ) {
			addTopExpression( sb, offset );
		}
		else {
			final String selectClause = fillAliasInSelectClause( sb, offset );

			if ( shallowIndexOfPattern( sb, ORDER_BY_PATTERN, offset ) > 0 ) {
				// ORDER BY requires using TOP
				addTopExpression( sb, offset );
			}

			encloseWithOuterQuery( sb, offset );

			sb.insert( offset, !isCTE ? "WITH query AS (" : ", query AS (" );
			sb.append( ") SELECT " ).append( selectClause ).append( " FROM query " );
			sb.append( "WHERE __hibernate_row_nr__ >= ? AND __hibernate_row_nr__ < ?" );
		}

		return sb.toString();
	}

	@Override
	public int bindLimitParametersAtStartOfQuery(RowSelection selection, PreparedStatement statement, int index) throws SQLException {
		if ( topAdded ) {
			// Binding TOP(?)
			statement.setInt( index, getMaxOrLimit( selection ) - 1 );
			return 1;
		}
		return 0;
	}

	@Override
	public int bindLimitParametersAtEndOfQuery(RowSelection selection, PreparedStatement statement, int index) throws SQLException {
		return LimitHelper.hasFirstRow( selection ) ? super.bindLimitParametersAtEndOfQuery( selection, statement, index ) : 0;
	}

	
Adds missing aliases in provided SELECT clause and returns coma-separated list of them. If query takes advantage of expressions like * or {table}.* inside SELECT clause, method returns *. 
Params:
sb – SQL query.
offset – the starting offset.
Returns:
List of aliases separated with comas or *./**
	 * Adds missing aliases in provided SELECT clause and returns coma-separated list of them.
	 * If query takes advantage of expressions like {@literal *} or {@literal {table}.*} inside SELECT clause,
	 * method returns {@literal *}.
	 *
	 * @param sb SQL query.
	 * @param offset the starting offset.
	 *
	 * @return List of aliases separated with comas or {@literal *}.
	 */
	protected String fillAliasInSelectClause(StringBuilder sb, int offset) {
		final String separator = System.lineSeparator();
		final List<String> aliases = new LinkedList<String>();
		final int startPos = getSelectColumnsStartPosition( sb, offset );
		int endPos = shallowIndexOfPattern( sb, FROM_PATTERN, startPos );

		int nextComa = startPos;
		int prevComa = startPos;
		int unique = 0;
		boolean selectsMultipleColumns = false;

		while ( nextComa != -1 ) {
			prevComa = nextComa;
			nextComa = shallowIndexOfPattern( sb, COMMA_PATTERN, nextComa );
			if ( nextComa > endPos ) {
				break;
			}
			if ( nextComa != -1 ) {
				final String expression = sb.substring( prevComa, nextComa );
				if ( selectsMultipleColumns( expression ) ) {
					selectsMultipleColumns = true;
				}
				else {
					String alias = getAlias( expression );
					if ( alias == null ) {
						// Inserting alias. It is unlikely that we would have to add alias, but just in case.
						alias = StringHelper.generateAlias( "page", unique );
						sb.insert( nextComa, " as " + alias );
						final int aliasExprLength = ( " as " + alias ).length();
						++unique;
						nextComa += aliasExprLength;
						endPos += aliasExprLength;
					}
					aliases.add( alias );
				}
				++nextComa;
			}
		}
		// Processing last column.
		// Refreshing end position, because we might have inserted new alias.
		endPos = shallowIndexOfPattern( sb, FROM_PATTERN, startPos );
		final String expression = sb.substring( prevComa, endPos );
		if ( selectsMultipleColumns( expression ) ) {
			selectsMultipleColumns = true;
		}
		else {
			String alias = getAlias( expression );
			if ( alias == null ) {
				// Inserting alias. It is unlikely that we would have to add alias, but just in case.
				alias = StringHelper.generateAlias( "page", unique );
				final boolean endWithSeparator = sb.substring( endPos - separator.length() ).startsWith( separator );
				sb.insert( endPos - ( endWithSeparator ? 2 : 1 ), " as " + alias );
			}
			aliases.add( alias );
		}

		// In case of '*' or '{table}.*' expressions adding an alias breaks SQL syntax, returning '*'.
		return selectsMultipleColumns ? "*" : String.join( ", ", aliases );
	}

	
Get the start position for where the column list begins.
Params:
sb – the string builder sql.
offset – the starting offset.
Returns:
the start position where the column list begins./**
	 * Get the start position for where the column list begins.
	 *
	 * @param sb the string builder sql.
	 * @param offset the starting offset.
	 * @return the start position where the column list begins.
	 */
	private int getSelectColumnsStartPosition(StringBuilder sb, int offset) {
		final int startPos = getSelectStartPosition( sb, offset );
		// adjustment for 'select distinct ' and 'select '.
		final String sql = sb.toString().substring( startPos ).toLowerCase();
		if ( sql.startsWith( SELECT_DISTINCT_SPACE ) ) {
			return ( startPos + SELECT_DISTINCT_SPACE.length() );
		}
		else if ( sql.startsWith( SELECT_SPACE ) ) {
			return ( startPos + SELECT_SPACE.length() );
		}
		return startPos;
	}

	
Get the select start position.
Params:
sb – the string builder sql.
offset – the starting offset in buffer.
Returns:
the position where select is found./**
	 * Get the select start position.
	 *
	 * @param sb the string builder sql.
	 * @param offset the starting offset in buffer.
	 * @return the position where {@code select} is found.
	 */
	private int getSelectStartPosition(StringBuilder sb, int offset) {
		return shallowIndexOfPattern( sb, SELECT_PATTERN, offset );
	}

	
Params:
expression – Select expression.
Returns:
true when expression selects multiple columns, false otherwise./**
	 * @param expression Select expression.
	 *
	 * @return {@code true} when expression selects multiple columns, {@code false} otherwise.
	 */
	private boolean selectsMultipleColumns(String expression) {
		final String lastExpr = expression.trim().replaceFirst( "(?i)(.)*\\s", "" ).trim();
		return "*".equals( lastExpr ) || lastExpr.endsWith( ".*" );
	}

	
Returns alias of provided single column selection or null if not found. Alias should be preceded with AS keyword. 
Params:
expression – Single column select expression.
Returns:
Column alias./**
	 * Returns alias of provided single column selection or {@code null} if not found.
	 * Alias should be preceded with {@code AS} keyword.
	 *
	 * @param expression Single column select expression.
	 *
	 * @return Column alias.
	 */
	private String getAlias(String expression) {
		// remove any function arguments, if any exist.
		// 'cast(tab1.col1 as varchar(255)) as col1' -> 'cast as col1'
		// 'cast(tab1.col1 as varchar(255)) col1 -> 'cast col1'
		// 'cast(tab1.col1 as varchar(255))' -> 'cast'
		expression = expression.replaceFirst( "(\\((.)*\\))", "" ).trim();

		// This will match any text provided with:
		// 		columnName [[as] alias]
		final Matcher matcher = ALIAS_PATTERN.matcher( expression );

		String alias = null;
		if ( matcher.find() && matcher.groupCount() > 1 ) {
			// default to the alias after 'as' if detected
			alias = matcher.group( 3 );
			if ( alias == null ) {
				// use the clause which has on proceeding 'as' fragment.
				alias = matcher.group( 0 );
			}
		}

		return ( alias != null ? alias.trim() : null );
	}

	
Encloses original SQL statement with outer query that provides __hibernate_row_nr__ column. 
Params:
sql – SQL query.
offset – SQL query offset./**
	 * Encloses original SQL statement with outer query that provides {@literal __hibernate_row_nr__} column.
	 *
	 * @param sql SQL query.
	 * @param offset SQL query offset.
	 */
	protected void encloseWithOuterQuery(StringBuilder sql, int offset) {
		sql.insert( offset, "SELECT inner_query.*, ROW_NUMBER() OVER (ORDER BY CURRENT_TIMESTAMP) as __hibernate_row_nr__ FROM ( " );
		sql.append( " ) inner_query " );
	}

	
Adds TOP expression. Parameter value is bind in bindLimitParametersAtStartOfQuery(RowSelection, PreparedStatement, int) method. 
Params:
sql – SQL query.
offset – the offset where top expression pattern matching should begin./**
	 * Adds {@code TOP} expression. Parameter value is bind in
	 * {@link #bindLimitParametersAtStartOfQuery(RowSelection, PreparedStatement, int)} method.
	 *
	 * @param sql SQL query.
	 * @param offset the offset where top expression pattern matching should begin.
	 */
	protected void addTopExpression(StringBuilder sql, int offset) {
		// We should use either of these which come first (SELECT or SELECT DISTINCT).
		final int selectPos = shallowIndexOfPattern( sql, SELECT_PATTERN, offset );
		final int selectDistinctPos = shallowIndexOfPattern( sql, SELECT_DISTINCT_PATTERN, offset );
		if ( selectPos == selectDistinctPos ) {
			// Place TOP after SELECT DISTINCT
			sql.insert( selectDistinctPos + SELECT_DISTINCT.length(), " TOP(?)" );
		}
		else {
			// Place TOP after SELECT
			sql.insert( selectPos + SELECT.length(), " TOP(?)" );
		}
		topAdded = true;
	}

	
Returns index of the first case-insensitive match of search pattern that is not
enclosed in parenthesis.
Params:
sb – String to search.
pattern – Compiled search pattern.
fromIndex – The index from which to start the search.
Returns:
Position of the first match, or -1 if not found./**
	 * Returns index of the first case-insensitive match of search pattern that is not
	 * enclosed in parenthesis.
	 *
	 * @param sb String to search.
	 * @param pattern Compiled search pattern.
	 * @param fromIndex The index from which to start the search.
	 *
	 * @return Position of the first match, or {@literal -1} if not found.
	 */
	private static int shallowIndexOfPattern(final StringBuilder sb, final Pattern pattern, int fromIndex) {
		int index = -1;
		final String matchString = sb.toString();

		// quick exit, save performance and avoid exceptions
		if ( matchString.length() < fromIndex || fromIndex < 0 ) {
			return -1;
		}

		List<IgnoreRange> ignoreRangeList = generateIgnoreRanges( matchString );

		Matcher matcher = pattern.matcher( matchString );
		matcher.region( fromIndex, matchString.length() );

		if ( ignoreRangeList.isEmpty() ) {
			// old behavior where the first match is used if no ignorable ranges
			// were deduced from the matchString.
			if ( matcher.find() && matcher.groupCount() > 0 ) {
				index = matcher.start();
			}
		}
		else {
			// rather than taking the first match, we now iterate all matches
			// until we determine a match that isn't considered "ignorable'.
			while ( matcher.find() && matcher.groupCount() > 0 ) {
				final int position = matcher.start();
				if ( !isPositionIgnorable( ignoreRangeList, position ) ) {
					index = position;
					break;
				}
			}
		}
		return index;
	}

	
Builds a pattern that can be used to find matches of case-insensitive matches
based on the search pattern that is not enclosed in parenthesis.
Params:
pattern – String search pattern.
wordBoundary – whether to apply a word boundary restriction.
Returns:
Compiled Pattern./**
	 * Builds a pattern that can be used to find matches of case-insensitive matches
	 * based on the search pattern that is not enclosed in parenthesis.
	 *
	 * @param pattern String search pattern.
	 * @param wordBoundary whether to apply a word boundary restriction.
	 * @return Compiled {@link Pattern}.
	 */
	private static Pattern buildShallowIndexPattern(String pattern, boolean wordBoundary) {
		return Pattern.compile(
				"(" +
				( wordBoundary ? "\\b" : "" ) +
				pattern +
				( wordBoundary ? "\\b" : "" ) +
				")(?![^\\(|\\[]*(\\)|\\]))",
				Pattern.CASE_INSENSITIVE
		);
	}

	
Geneartes a list of IgnoreRange objects that represent nested sections of the provided SQL buffer that should be ignored when performing regular expression matches. 
Params:
sql – The SQL buffer.
Returns:
list of IgnoreRange objects, never null./**
	 * Geneartes a list of {@code IgnoreRange} objects that represent nested sections of the
	 * provided SQL buffer that should be ignored when performing regular expression matches.
	 *
	 * @param sql The SQL buffer.
	 * @return list of {@code IgnoreRange} objects, never {@code null}.
	 */
	private static List<IgnoreRange> generateIgnoreRanges(String sql) {
		List<IgnoreRange> ignoreRangeList = new ArrayList<IgnoreRange>();

		int depth = 0;
		int start = -1;
		boolean insideAStringValue = false;
		for ( int i = 0; i < sql.length(); ++i ) {
			final char ch = sql.charAt( i );
			if ( ch == '\'' ) {
				insideAStringValue = !insideAStringValue;
			}
			else if ( ch == '(' && !insideAStringValue ) {
				depth++;
				if ( depth == 1 ) {
					start = i;
				}
			}
			else if ( ch == ')' && !insideAStringValue ) {
				if ( depth > 0 ) {
					if ( depth == 1 ) {
						ignoreRangeList.add( new IgnoreRange( start, i ) );
						start = -1;
					}
					depth--;
				}
				else {
					throw new IllegalStateException( "Found an unmatched ')' at position " + i + ": " + sql );
				}
			}
		}

		if ( depth != 0 ) {
			throw new IllegalStateException( "Unmatched parenthesis in rendered SQL (" + depth + " depth): " + sql );
		}

		return ignoreRangeList;
	}

	
Returns whether the specified position is within the ranges of the ignoreRangeList. 
Params:
ignoreRangeList – list of IgnoreRange objects deduced from the SQL buffer.
position – the position to determine whether is ignorable.
Returns:
true if the position is to ignored/skipped, false otherwise./**
	 * Returns whether the specified {@code position} is within the ranges of the {@code ignoreRangeList}.
	 *
	 * @param ignoreRangeList list of {@code IgnoreRange} objects deduced from the SQL buffer.
	 * @param position the position to determine whether is ignorable.
	 * @return {@code true} if the position is to ignored/skipped, {@code false} otherwise.
	 */
	private static boolean isPositionIgnorable(List<IgnoreRange> ignoreRangeList, int position) {
		for ( IgnoreRange ignoreRange : ignoreRangeList ) {
			if ( ignoreRange.isWithinRange( position ) ) {
				return true;
			}
		}
		return false;
	}

	static class IgnoreRange {
		private int start;
		private int end;

		IgnoreRange(int start, int end) {
			this.start = start;
			this.end = end;
		}

		boolean isWithinRange(int position) {
			return position >= start && position <= end;
		}
	}

	
Get the starting point for the limit handler to begin injecting and transforming the SQL. For non-CTE queries, this is offset 0. For CTE queries, this will be where the CTE's SELECT clause begins (skipping all query definitions, column definitions and expressions). This method also sets isCTE if the query is parsed as a CTE query. 
Params:
sql – The sql buffer.
Returns:
the index where to begin parsing./**
	 * Get the starting point for the limit handler to begin injecting and transforming the SQL.
	 * For non-CTE queries, this is offset 0.  For CTE queries, this will be where the CTE's
	 * SELECT clause begins (skipping all query definitions, column definitions and expressions).
	 *
	 * This method also sets {@code isCTE} if the query is parsed as a CTE query.
	 *
	 * @param sql The sql buffer.
	 * @return the index where to begin parsing.
	 */
	private int getStatementIndex(StringBuilder sql) {
		final Matcher matcher = WITH_CTE.matcher( sql.toString() );
		if ( matcher.find() && matcher.groupCount() > 0 ) {
			isCTE = true;
			return locateQueryInCTEStatement( sql, matcher.end() );
		}
		return 0;
	}

	
Steps through the SQL buffer from the specified offset and performs a series of pattern matches.
The method locates where the CTE SELECT clause begins and returns that offset from the SQL buffer.
Params:
sql – The sql buffer.
offset – The offset to begin pattern matching.
Throws:
IllegalArgumentException – if the parse of the CTE query fails.
Returns:
the offset where the CTE SELECT clause begins./**
	 * Steps through the SQL buffer from the specified offset and performs a series of pattern matches.
	 * The method locates where the CTE SELECT clause begins and returns that offset from the SQL buffer.
	 *
	 * @param sql The sql buffer.
	 * @param offset The offset to begin pattern matching.
	 *
	 * @return the offset where the CTE SELECT clause begins.
	 * @throws IllegalArgumentException if the parse of the CTE query fails.
	 */
	private int locateQueryInCTEStatement(StringBuilder sql, int offset) {
		while ( true ) {
			Matcher matcher = WITH_EXPRESSION_NAME.matcher( sql.substring( offset ) );
			if ( matcher.find() && matcher.groupCount() > 0 ) {
				offset += matcher.end();
				matcher = WITH_COLUMN_NAMES_START.matcher( sql.substring( offset ) );
				if ( matcher.find() && matcher.groupCount() > 0 ) {
					offset += matcher.end();
					matcher = WITH_COLUMN_NAMES_END.matcher( sql.substring( offset ) );
					if ( matcher.find() && matcher.groupCount() > 0 ) {
						offset += matcher.end();
						offset += advanceOverCTEInnerQuery( sql, offset );
						matcher = WITH_COMMA.matcher( sql.substring( offset ) );
						if ( matcher.find() && matcher.groupCount() > 0 ) {
							// another CTE fragment exists, re-start parse of CTE
							offset += matcher.end();
						}
						else {
							// last CTE fragment, we're at the start of the SQL.
							return offset;
						}
					}
					else {
						throw new IllegalArgumentException(
								String.format(
										Locale.ROOT,
										"Failed to parse CTE expression columns at offset %d, SQL [%s]",
										offset,
										sql.toString()
								)
						);
					}
				}
				else {
					matcher = WITH_AS.matcher( sql.substring( offset ) );
					if ( matcher.find() && matcher.groupCount() > 0 ) {
						offset += matcher.end();
						offset += advanceOverCTEInnerQuery( sql, offset );
						matcher = WITH_COMMA.matcher( sql.substring( offset ) );
						if ( matcher.find() && matcher.groupCount() > 0 ) {
							// another CTE fragment exists, re-start parse of CTE
							offset += matcher.end();
						}
						else {
							// last CTE fragment, we're at the start of the SQL.
							return offset;
						}
					}
					else {
						throw new IllegalArgumentException(
								String.format(
										Locale.ROOT,
										"Failed to locate AS keyword in CTE query at offset %d, SQL [%s]",
										offset,
										sql.toString()
								)
						);
					}
				}
			}
			else {
				throw new IllegalArgumentException(
						String.format(
								Locale.ROOT,
								"Failed to locate CTE expression name at offset %d, SQL [%s]",
								offset,
								sql.toString()
						)
				);
			}
		}
	}

	
Advances over the CTE inner query that is contained inside matching '(' and ')'.
Params:
sql – The sql buffer.
offset – The offset where to begin advancing the position from.
Throws:
IllegalArgumentException – if the matching parenthesis aren't detected at the end of the parse.
Returns:
the position immediately after the CTE inner query plus 1./**
	 * Advances over the CTE inner query that is contained inside matching '(' and ')'.
	 *
	 * @param sql The sql buffer.
	 * @param offset The offset where to begin advancing the position from.
	 * @return the position immediately after the CTE inner query plus 1.
	 *
	 * @throws IllegalArgumentException if the matching parenthesis aren't detected at the end of the parse.
	 */
	private int advanceOverCTEInnerQuery(StringBuilder sql, int offset) {
		int brackets = 0;
		int index = offset;
		boolean inString = false;
		for ( ; index < sql.length(); ++index ) {
			if ( sql.charAt( index ) == '\'' ) {
				inString = true;
			}
			else if ( sql.charAt( index ) == '\'' && inString ) {
				inString = false;
			}
			else if ( sql.charAt( index ) == '(' && !inString ) {
				brackets++;
			}
			else if ( sql.charAt( index ) == ')' && !inString ) {
				brackets--;
				if ( brackets == 0 ) {
					break;
				}
			}
		}

		if ( brackets > 0 ) {
			throw new IllegalArgumentException(
					"Failed to parse the CTE query inner query because closing ')' was not found."
			);
		}

		return index - offset + 1;
	}
}