/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2009 by Red Hat Inc and/or its affiliates or by
 * third-party contributors as indicated by either @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.expression;

import java.io.Serializable;
import javax.persistence.criteria.Expression;
import org.hibernate.ejb.criteria.ParameterRegistry;
import org.hibernate.ejb.criteria.CriteriaBuilderImpl;
import org.hibernate.ejb.criteria.CriteriaQueryCompiler;
import org.hibernate.ejb.criteria.Renderable;

/**
 * A string concatenation.
 *
 * @author Steve Ebersole
 */
public class ConcatExpression extends ExpressionImpl<String> implements Serializable {
	private Expression<String> string1;
	private Expression<String> string2;

	public ConcatExpression(
			CriteriaBuilderImpl criteriaBuilder,
			Expression<String> expression1,
			Expression<String> expression2) {
		super( criteriaBuilder, String.class );
		this.string1 = expression1;
		this.string2 = expression2;
	}

	public ConcatExpression(
			CriteriaBuilderImpl criteriaBuilder,
			Expression<String> string1, 
			String string2) {
		this( criteriaBuilder, string1, wrap( criteriaBuilder, string2) );
	}

	private static Expression<String> wrap(CriteriaBuilderImpl criteriaBuilder, String string) {
		return new LiteralExpression<String>( criteriaBuilder, string );
	}

	public ConcatExpression(
			CriteriaBuilderImpl criteriaBuilder,
			String string1,
			Expression<String> string2) {
		this( criteriaBuilder, wrap( criteriaBuilder, string1), string2 );
	}

	public Expression<String> getString1() {
		return string1;
	}

	public Expression<String> getString2() {
		return string2;
	}

	public void registerParameters(ParameterRegistry registry) {
		Helper.possibleParameter( getString1(), registry );
		Helper.possibleParameter( getString2(), registry );
	}

	public String render(CriteriaQueryCompiler.RenderingContext renderingContext) {
		return ( (Renderable) getString1() ).render( renderingContext )
				+ " || "
				+ ( (Renderable) getString2() ).render( renderingContext );
	}

	public String renderProjection(CriteriaQueryCompiler.RenderingContext renderingContext) {
		return render( renderingContext );
	}
}
