/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008-2011, 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.bytecode.instrumentation.spi;
import java.io.Serializable;
import java.util.Set;
import org.hibernate.LazyInitializationException;
import org.hibernate.engine.spi.SessionImplementor;

/**
 * @author Steve Ebersole
 */
public abstract class AbstractFieldInterceptor implements FieldInterceptor, Serializable {

	private transient SessionImplementor session;
	private Set uninitializedFields;
	private final String entityName;

	private transient boolean initializing;
	private boolean dirty;

	protected AbstractFieldInterceptor(SessionImplementor session, Set uninitializedFields, String entityName) {
		this.session = session;
		this.uninitializedFields = uninitializedFields;
		this.entityName = entityName;
	}


	// FieldInterceptor impl ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	public final void setSession(SessionImplementor session) {
		this.session = session;
	}

	public final boolean isInitialized() {
		return uninitializedFields == null || uninitializedFields.size() == 0;
	}

	public final boolean isInitialized(String field) {
		return uninitializedFields == null || !uninitializedFields.contains( field );
	}

	public final void dirty() {
		dirty = true;
	}

	public final boolean isDirty() {
		return dirty;
	}

	public final void clearDirty() {
		dirty = false;
	}


	// subclass accesses ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	protected final Object intercept(Object target, String fieldName, Object value) {
		if ( initializing ) {
			return value;
		}

		if ( uninitializedFields != null && uninitializedFields.contains( fieldName ) ) {
			if ( session == null ) {
				throw new LazyInitializationException( "entity with lazy properties is not associated with a session" );
			}
			else if ( !session.isOpen() || !session.isConnected() ) {
				throw new LazyInitializationException( "session is not connected" );
			}

			final Object result;
			initializing = true;
			try {
				result = ( ( LazyPropertyInitializer ) session.getFactory()
						.getEntityPersister( entityName ) )
						.initializeLazyProperty( fieldName, target, session );
			}
			finally {
				initializing = false;
			}
			uninitializedFields = null; //let's assume that there is only one lazy fetch group, for now!
			return result;
		}
		else {
			return value;
		}
	}

	public final SessionImplementor getSession() {
		return session;
	}

	public final Set getUninitializedFields() {
		return uninitializedFields;
	}

	public final String getEntityName() {
		return entityName;
	}

	public final boolean isInitializing() {
		return initializing;
	}
}