/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program 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 distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.ejb.criteria.predicate;
import java.io.Serializable;
import javax.persistence.criteria.Expression;
import org.hibernate.ejb.criteria.CriteriaBuilderImpl;
import org.hibernate.ejb.criteria.CriteriaQueryCompiler;
import org.hibernate.ejb.criteria.ParameterRegistry;
import org.hibernate.ejb.criteria.Renderable;

/**
 * Predicate to assert the explicit value of a boolean expression:<ul>
 * <li>x = true</li>
 * <li>x = false</li>
 * <li>x <> true</li>
 * <li>x <> false</li>
 * </ul>
 *
 * @author Steve Ebersole
 */
public class BooleanAssertionPredicate
		extends AbstractSimplePredicate
		implements Serializable {
	private final Expression<Boolean> expression;
	private final Boolean assertedValue;

	public BooleanAssertionPredicate(
			CriteriaBuilderImpl criteriaBuilder,
			Expression<Boolean> expression,
			Boolean assertedValue) {
		super( criteriaBuilder );
		this.expression = expression;
		this.assertedValue = assertedValue;
	}

	public Expression<Boolean> getExpression() {
		return expression;
	}

	public Boolean getAssertedValue() {
		return assertedValue;
	}

	/**
	 * {@inheritDoc}
	 */
	public void registerParameters(ParameterRegistry registry) {
		Helper.possibleParameter( expression, registry );
	}

	/**
	 * {@inheritDoc}
	 */
	public String render(CriteriaQueryCompiler.RenderingContext renderingContext) {
		final String operator = isNegated() ? " <> " : " = ";
		final String assertionLiteral = assertedValue ? "true" : "false";

		return ( (Renderable) expression ).render( renderingContext )
				+ operator
				+ assertionLiteral;
	}

	/**
	 * {@inheritDoc}
	 */
	public String renderProjection(CriteriaQueryCompiler.RenderingContext renderingContext) {
		return render( renderingContext );
	}

}