/*
 * 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.sql.ordering.antlr;

import org.hibernate.NullPrecedence;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.hql.internal.ast.util.ASTPrinter;
import org.hibernate.hql.internal.ast.util.TokenPrinters;
import org.hibernate.internal.util.StringHelper;

import org.jboss.logging.Logger;

import antlr.collections.AST;

Extension of the Antlr-generated tree walker for rendering the parsed order-by tree back to String form. out(AST) is the sole semantic action here and it is used to utilize our split between text (tree debugging text) and "renderable text" (text to use during rendering). 
Author:
Steve Ebersole/**
 * Extension of the Antlr-generated tree walker for rendering the parsed order-by tree back to String form.
 * {@link #out(antlr.collections.AST)} is the sole semantic action here and it is used to utilize our
 * split between text (tree debugging text) and "renderable text" (text to use during rendering).
 *
 * @author Steve Ebersole
 */
public class OrderByFragmentRenderer extends GeneratedOrderByFragmentRenderer {

	private static final Logger LOG = Logger.getLogger( OrderByFragmentRenderer.class.getName() );

	private final SessionFactoryImplementor sessionFactory;

	public OrderByFragmentRenderer(SessionFactoryImplementor sessionFactory) {
		this.sessionFactory = sessionFactory;
	}

	@Override
	protected void out(AST ast) {
		out( ( (Node) ast ).getRenderableText() );
	}


	// handle trace logging ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	private int traceDepth = 0;

	@Override
	public void traceIn(String ruleName, AST tree) {
		if ( inputState.guessing > 0 ) {
			return;
		}
		String prefix = StringHelper.repeat( '-', ( traceDepth++ * 2 ) ) + "-> ";
		String traceText = ruleName + " (" + buildTraceNodeName( tree ) + ")";
		LOG.trace( prefix + traceText );
	}

	private String buildTraceNodeName(AST tree) {
		return tree == null
				? "???"
				: tree.getText() + " [" + TokenPrinters.ORDERBY_FRAGMENT_PRINTER.getTokenTypeName( tree.getType() ) + "]";
	}

	@Override
	public void traceOut(String ruleName, AST tree) {
		if ( inputState.guessing > 0 ) {
			return;
		}
		String prefix = "<-" + StringHelper.repeat( '-', ( --traceDepth * 2 ) ) + " ";
		LOG.trace( prefix + ruleName );
	}

	@Override
	protected String renderOrderByElement(String expression, String collation, String order, String nulls) {
		final NullPrecedence nullPrecedence = NullPrecedence.parse(
				nulls,
				sessionFactory.getSessionFactoryOptions().getDefaultNullPrecedence()
		);
		return sessionFactory.getDialect().renderOrderByElement( expression, collation, order, nullPrecedence );
	}
}