/*
 * 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
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 */
package org.hibernate.jpa.criteria.path;

import java.io.Serializable;
import javax.persistence.metamodel.Attribute;
import javax.persistence.metamodel.Bindable;
import javax.persistence.metamodel.PluralAttribute;

import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.jpa.criteria.CriteriaBuilderImpl;
import org.hibernate.jpa.criteria.PathSource;
import org.hibernate.persister.collection.CollectionPersister;

Models a path for a PluralAttribute generally obtained from a Path.get call 
Author:
Steve Ebersole/**
 * Models a path for a {@link PluralAttribute} generally obtained from a
 * {@link javax.persistence.criteria.Path#get} call
 *
 * @author Steve Ebersole
 */
public class PluralAttributePath<X> extends AbstractPathImpl<X> implements Serializable {
	private final PluralAttribute<?,X,?> attribute;
	private final CollectionPersister persister;

	public PluralAttributePath(
			CriteriaBuilderImpl criteriaBuilder,
			PathSource source,
			PluralAttribute<?,X,?> attribute) {
		super( criteriaBuilder, attribute.getJavaType(), source );
		this.attribute = attribute;
		this.persister = resolvePersister( criteriaBuilder, attribute );
	}

	private static CollectionPersister resolvePersister(CriteriaBuilderImpl criteriaBuilder, PluralAttribute attribute) {
		SessionFactoryImplementor sfi = criteriaBuilder.getEntityManagerFactory().getSessionFactory();
		return sfi.getCollectionPersister( resolveRole( attribute ) );
	}

	private static String resolveRole(PluralAttribute attribute) {
		return attribute.getDeclaringType().getJavaType().getName() +
				'.' + attribute.getName();
	}

	public PluralAttribute<?,X,?> getAttribute() {
		return attribute;
	}

	@SuppressWarnings({ "UnusedDeclaration" })
	public CollectionPersister getPersister() {
		return persister;
	}

	@Override
	protected boolean canBeDereferenced() {
		// cannot be dereferenced
		return false;
	}

	@Override
	protected Attribute locateAttributeInternal(String attributeName) {
		throw new IllegalArgumentException( "Plural attribute paths cannot be further dereferenced" );
	}

	public Bindable<X> getModel() {
		// the issue here is the parameterized type; X is the collection
		// type (Map, Set, etc) while the "bindable" for a collection is the
		// elements.
		//
		// TODO : throw exception instead?
		return null;
	}

	@Override
	public <T extends X> PluralAttributePath<T> treatAs(Class<T> treatAsType) {
		throw new UnsupportedOperationException(
				"Plural attribute path [" + getPathSource().getPathIdentifier() + '.'
						+ attribute.getName() + "] cannot be dereferenced"
		);
	}
}