/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC 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 Middleware LLC.
 *
 * 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.envers.entities.mapper.relation.lazy.initializor;
import java.util.List;
import org.hibernate.envers.configuration.AuditConfiguration;
import org.hibernate.envers.entities.EntityInstantiator;
import org.hibernate.envers.entities.mapper.relation.query.RelationQueryGenerator;
import org.hibernate.envers.reader.AuditReaderImplementor;

/**
 * Initializes a persistent collection.
 * @author Adam Warski (adam at warski dot org)
 */
public abstract class AbstractCollectionInitializor<T> implements Initializor<T> {
    private final AuditReaderImplementor versionsReader;
    private final RelationQueryGenerator queryGenerator;
    private final Object primaryKey;
    
    protected final Number revision;
    protected final EntityInstantiator entityInstantiator;

    public AbstractCollectionInitializor(AuditConfiguration verCfg,
                                         AuditReaderImplementor versionsReader,
                                         RelationQueryGenerator queryGenerator,
                                         Object primaryKey, Number revision) {
        this.versionsReader = versionsReader;
        this.queryGenerator = queryGenerator;
        this.primaryKey = primaryKey;
        this.revision = revision;

        entityInstantiator = new EntityInstantiator(verCfg, versionsReader);
    }

    protected abstract T initializeCollection(int size);

    protected abstract void addToCollection(T collection, Object collectionRow);

    public T initialize() {
        List<?> collectionContent = queryGenerator.getQuery(versionsReader, primaryKey, revision).list();

        T collection = initializeCollection(collectionContent.size());

        for (Object collectionRow : collectionContent) {
            addToCollection(collection, collectionRow);
        }

        return collection;
    }
}