/*
 * 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.internal.javassist;

import java.lang.reflect.Modifier;
import java.util.Set;

import org.jboss.logging.Logger;

import org.hibernate.bytecode.buildtime.spi.ClassFilter;
import org.hibernate.bytecode.buildtime.spi.FieldFilter;
import org.hibernate.bytecode.instrumentation.internal.javassist.JavassistHelper;
import org.hibernate.bytecode.instrumentation.spi.FieldInterceptor;
import org.hibernate.bytecode.spi.BytecodeProvider;
import org.hibernate.bytecode.spi.ClassTransformer;
import org.hibernate.bytecode.spi.EntityInstrumentationMetadata;
import org.hibernate.bytecode.spi.NotInstrumentedException;
import org.hibernate.bytecode.spi.ProxyFactoryFactory;
import org.hibernate.bytecode.spi.ReflectionOptimizer;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.internal.util.StringHelper;

/**
 * Bytecode provider implementation for Javassist.
 *
 * @author Steve Ebersole
 */
public class BytecodeProviderImpl implements BytecodeProvider {

    private static final CoreMessageLogger LOG = Logger.getMessageLogger(CoreMessageLogger.class, BytecodeProviderImpl.class.getName());

	@Override
	public ProxyFactoryFactory getProxyFactoryFactory() {
		return new ProxyFactoryFactoryImpl();
	}

	@Override
	public ReflectionOptimizer getReflectionOptimizer(
			Class clazz,
	        String[] getterNames,
	        String[] setterNames,
	        Class[] types) {
		FastClass fastClass;
		BulkAccessor bulkAccessor;
		try {
			fastClass = FastClass.create( clazz );
			bulkAccessor = BulkAccessor.create( clazz, getterNames, setterNames, types );
			if ( !clazz.isInterface() && !Modifier.isAbstract( clazz.getModifiers() ) ) {
				if ( fastClass == null ) {
					bulkAccessor = null;
				}
				else {
					//test out the optimizer:
					Object instance = fastClass.newInstance();
					bulkAccessor.setPropertyValues( instance, bulkAccessor.getPropertyValues( instance ) );
				}
			}
		}
		catch ( Throwable t ) {
			fastClass = null;
			bulkAccessor = null;
            if (LOG.isDebugEnabled()) {
                int index = 0;
                if (t instanceof BulkAccessorException) index = ((BulkAccessorException)t).getIndex();
                if (index >= 0) LOG.debugf("Reflection optimizer disabled for: %s [%s: %s (property %s)",
                                           clazz.getName(),
                                           StringHelper.unqualify(t.getClass().getName()),
                                           t.getMessage(),
                                           setterNames[index]);
                else LOG.debugf("Reflection optimizer disabled for: %s [%s: %s",
                                clazz.getName(),
                                StringHelper.unqualify(t.getClass().getName()),
                                t.getMessage());
            }
		}

		if ( fastClass != null && bulkAccessor != null ) {
			return new ReflectionOptimizerImpl(
					new InstantiationOptimizerAdapter( fastClass ),
			        new AccessOptimizerAdapter( bulkAccessor, clazz )
			);
		}
        return null;
	}

	@Override
	public ClassTransformer getTransformer(ClassFilter classFilter, FieldFilter fieldFilter) {
		return new JavassistClassTransformer( classFilter, fieldFilter );
	}

	@Override
	public EntityInstrumentationMetadata getEntityInstrumentationMetadata(Class entityClass) {
		return new EntityInstrumentationMetadataImpl( entityClass );
	}

	private class EntityInstrumentationMetadataImpl implements EntityInstrumentationMetadata {
		private final Class entityClass;
		private final boolean isInstrumented;

		private EntityInstrumentationMetadataImpl(Class entityClass) {
			this.entityClass = entityClass;
			this.isInstrumented = FieldHandled.class.isAssignableFrom( entityClass );
		}

		@Override
		public String getEntityName() {
			return entityClass.getName();
		}

		@Override
		public boolean isInstrumented() {
			return isInstrumented;
		}

		@Override
		public FieldInterceptor extractInterceptor(Object entity) throws NotInstrumentedException {
			if ( !entityClass.isInstance( entity ) ) {
				throw new IllegalArgumentException(
						String.format(
								"Passed entity instance [%s] is not of expected type [%s]",
								entity,
								getEntityName()
						)
				);
			}
			if ( ! isInstrumented() ) {
				throw new NotInstrumentedException( String.format( "Entity class [%s] is not instrumented", getEntityName() ) );
			}
			return JavassistHelper.extractFieldInterceptor( entity );
		}

		@Override
		public FieldInterceptor injectInterceptor(
				Object entity,
				String entityName,
				Set uninitializedFieldNames,
				SessionImplementor session) throws NotInstrumentedException {
			if ( !entityClass.isInstance( entity ) ) {
				throw new IllegalArgumentException(
						String.format(
								"Passed entity instance [%s] is not of expected type [%s]",
								entity,
								getEntityName()
						)
				);
			}
			if ( ! isInstrumented() ) {
				throw new NotInstrumentedException( String.format( "Entity class [%s] is not instrumented", getEntityName() ) );
			}
			return JavassistHelper.injectFieldInterceptor( entity, entityName, uninitializedFieldNames, session );
		}
	}
}