package org.hibernate.intercept;

import org.hibernate.engine.SessionImplementor;
import org.hibernate.intercept.cglib.CGLIBHelper;
import org.hibernate.intercept.javassist.JavassistHelper;

import java.util.Set;

/**
 * Helper class for dealing with enhanced entity classes.
 *
 * @author Steve Ebersole
 */
public class FieldInterceptionHelper {

	// VERY IMPORTANT!!!! - This class needs to be free of any static references
	// to any CGLIB or Javassist classes.  Otherwise, users will always need both
	// on their classpaths no matter which (if either) they use.
	//
	// Another option here would be to remove the Hibernate.isPropertyInitialized()
	// method and have the users go through the SessionFactory to get this information.

	private FieldInterceptionHelper() {
	}

	public static boolean isInstrumented(Class entityClass) {
		Class[] definedInterfaces = entityClass.getInterfaces();
		for ( int i = 0; i < definedInterfaces.length; i++ ) {
			if ( "net.sf.cglib.transform.impl.InterceptFieldEnabled".equals( definedInterfaces[i].getName() )
			     || "org.hibernate.bytecode.javassist.FieldHandled".equals( definedInterfaces[i].getName() ) ) {
				return true;
			}
		}
		return false;
	}

	public static boolean isInstrumented(Object entity) {
		return entity != null && isInstrumented( entity.getClass() );
	}

	public static FieldInterceptor extractFieldInterceptor(Object entity) {
		if ( entity == null ) {
			return null;
		}
		Class[] definedInterfaces = entity.getClass().getInterfaces();
		for ( int i = 0; i < definedInterfaces.length; i++ ) {
			if ( "net.sf.cglib.transform.impl.InterceptFieldEnabled".equals( definedInterfaces[i].getName() ) ) {
				// we have a CGLIB enhanced entity
				return CGLIBHelper.extractFieldInterceptor( entity );
			}
			else if ( "org.hibernate.bytecode.javassist.FieldHandled".equals( definedInterfaces[i].getName() ) ) {
				// we have a Javassist enhanced entity
				return JavassistHelper.extractFieldInterceptor( entity );
			}
		}
		return null;
	}

	public static FieldInterceptor injectFieldInterceptor(
			Object entity,
	        String entityName,
	        Set uninitializedFieldNames,
	        SessionImplementor session) {
		if ( entity != null ) {
			Class[] definedInterfaces = entity.getClass().getInterfaces();
			for ( int i = 0; i < definedInterfaces.length; i++ ) {
				if ( "net.sf.cglib.transform.impl.InterceptFieldEnabled".equals( definedInterfaces[i].getName() ) ) {
					// we have a CGLIB enhanced entity
					return CGLIBHelper.injectFieldInterceptor( entity, entityName, uninitializedFieldNames, session );
				}
				else if ( "org.hibernate.bytecode.javassist.FieldHandled".equals( definedInterfaces[i].getName() ) ) {
					// we have a Javassist enhanced entity
					return JavassistHelper.injectFieldInterceptor( entity, entityName, uninitializedFieldNames, session );
				}
			}
		}
		return null;
	}

	public static void clearDirty(Object entity) {
		FieldInterceptor interceptor = extractFieldInterceptor( entity );
		if ( interceptor != null ) {
			interceptor.clearDirty();
		}
	}

	public static void markDirty(Object entity) {
		FieldInterceptor interceptor = extractFieldInterceptor( entity );
		if ( interceptor != null ) {
			interceptor.dirty();
		}
	}
}