/*
 This file belongs to the Servoy development and deployment environment, Copyright (C) 1997-2010 Servoy BV

 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU Affero General Public License as published by the Free
 Software Foundation; either version 3 of the License, or (at your option) any
 later version.

 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 Affero General Public License for more details.

 You should have received a copy of the GNU Affero General Public License along
 with this program; if not, see http://www.gnu.org/licenses or write to the Free
 Software Foundation,Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 */
package com.servoy.j2db.util.visitor;

import java.lang.reflect.InvocationTargetException;

import com.servoy.j2db.query.IQueryElement;
import com.servoy.j2db.util.Immutable;

/**
 * Visitor class to for performing a deep clone that maintains tree structure.
 * 
 * @see IVisitable
 * @author rgansevles
 * 
 */
public class DeepCloneVisitor implements IVisitor
{
	public static IVisitor createDeepCloneVisitor()
	{
		return new VisitOnceDelegateVisitor(new DeepCloneVisitor());
	}

	private DeepCloneVisitor()
	{
	}

	public Object visit(Object o)
	{
		if (o == null || o instanceof Immutable)
		{
			// do not need to make a copy
			return new IVisitor.VistorResult(o, false);
		}

		try
		{
			if (o instanceof IQueryElement)
			{
				return ((IQueryElement)o).shallowClone();
			}

			// don't know why we can't use the reflection method below for object arrays, it throws NoSuchMethodException
			if (o instanceof Object[])
			{
				return ((Object[])o).clone();
			}
			if (o instanceof byte[])
			{
				return ((byte[])o).clone();
			}
			if (o instanceof int[])
			{
				return ((int[])o).clone();
			}
			if (o instanceof short[])
			{
				return ((short[])o).clone();
			}
			if (o instanceof long[])
			{
				return ((long[])o).clone();
			}
			if (o instanceof float[])
			{
				return ((float[])o).clone();
			}
			if (o instanceof double[])
			{
				return ((double[])o).clone();
			}
			if (o instanceof char[])
			{
				return ((char[])o).clone();
			}
			if (o instanceof boolean[])
			{
				return ((boolean[])o).clone();
			}

			// something else than the known stuff, is there a clone method?
			if (o instanceof Cloneable)
			{
				try
				{
					// assume clone() is a shallow clone like it is for ArrayList, HashMap, Object[] etc.
					return o.getClass().getMethod("clone", (Class[])null).invoke(o, (Object[])null); //$NON-NLS-1$
				}
				catch (NoSuchMethodException e)
				{
					// Cloneable but no clone method???
					throw new RuntimeException("Cannot clone Cloneable class " + o.getClass()); //$NON-NLS-1$
				}
				catch (Exception e)
				{
					if (e instanceof InvocationTargetException && ((InvocationTargetException)e).getTargetException() instanceof CloneNotSupportedException)
					{
						throw (CloneNotSupportedException)((InvocationTargetException)e).getTargetException();
					}
					throw new CloneNotSupportedException(o.getClass().getName());
				}
			}

			// cannot clone, assume immutable primitives like Integer, String
			return o;
		}
		catch (CloneNotSupportedException e)
		{
			throw new RuntimeException("Clone not supported in class " + o.getClass(), e); //$NON-NLS-1$
		}
	}
}