/*
	$Id: AChildItem.txt 4889 2009-04-06 12:52:39Z nicklas $

	Copyright (C) 2005 Nicklas Nordborg
	Copyright (C) 2006 Jari Häkkinen

	This file is part of BASE - BioArray Software Environment.
	Available at http://base.thep.lu.se/

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

	BASE 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 General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with BASE. If not, see <http://www.gnu.org/licenses/>.
*/
package net.sf.basedb.core;
import net.sf.basedb.core.data.ChildData;
import net.sf.basedb.core.data.SharedData;
/**
	This class is used to represent a child item to {@link AnyItem} in BASE.

	@author Your name
	@version 2.0
	@see ChildData
	@base.modified $Date: 2009-04-06 14:52:39 +0200 (må, 06 apr 2009) $
*/
public class AChildItem
	extends ChildItem<AnyChildData>
	implements Nameable
{

	private static final QueryRuntimeFilter RUNTIME_FILTER = 
		new QueryRuntimeFilterFactory.ChildFilter(Item.CHILDITEM, Item.ANYITEM);

	/**
		Create a new <code>ChildItem</code> item.

		@param dc The <code>DbControl</code> which will be used for
			permission checking and database access
		@param parent The <code>AnyItem</code> which is the parent
		@return The new <code>ChildItem</code> item
		@throws BaseException If there is an error
		@see AnyItem#newChildItem()
	*/
	public static AChildItem getNew(DbControl dc, AnyItem parent)
		throws BaseException
	{
		AChildItem c = dc.newItem(AChildItem.class);
		c.setParent(parent);
		c.setName("New child item");
		return c;
	}

	/**
		Get a <code>ChildItem</code> item when you know the id.

		@param dc The <code>DbControl</code> which will be used for
			permission checking and database access.
		@param id The id of the item to load
		@return The <code>ChildItem</code> item
		@throws ItemNotFoundException If an item with the specified 
			id is not found
		@throws PermissionDeniedException If the logged in user doesn't 
			have {@link Permission#READ} permission to the item
		@throws BaseException If there is another error
	*/
	public static AChildItem getById(DbControl dc, int id)
		throws ItemNotFoundException, PermissionDeniedException, BaseException
	{
		AChildItem c = dc.loadItem(AChildItem.class, id);
		if (c == null) throw new ItemNotFoundException("AChildItem[id="+id+"]");
		return c;
	}

	/**
		Get a query configured to retrieve children for the specified parent.
		
		@param parent The parent to retreive child items for, null is allowed if
			the logged in user has generic READ permission for AnyItem:s in which case
			all ChildItems will be returned
		@return An {@link ItemQuery} object
		@see AnyItem#getChildItems()
	*/
	public static ItemQuery<AChildItem> getQuery(AnyItem parent)
	{
		Query<AChildItem> query = null;
		if (parent != null)
		{
			query = new ItemQuery<AChildItem>(AChildItem.class, null);
			query.restrictPermanent(
				Restrictions.eq(
					Hql.property("anyItem"), 
					Hql.entity(parent)
				)
			);
		}
		else
		{
			query = new ItemQuery<AChildItem>(AChildItem.class, RUNTIME_FILTER);
		}
		return query;
	}

	// Constructor
	AChildItem(ChildData childData)
	{
		super(childData);
	}

	/*
		From the Nameable interface
		-------------------------------------------
	*/
	public String getName()
	{
		return getData().getName();
	}
	public void setName(String name)
		throws PermissionDeniedException, InvalidDataException
	{
		checkPermission(Permission.WRITE);
		NameableUtil.setName(getData(), name);
	}
	public String getDescription()
	{
		return getData().getDescription();
	}
	public void setDescription(String description)
		throws PermissionDeniedException, InvalidDataException
	{
		checkPermission(Permission.WRITE);
		NameableUtil.setDescription(getData(), description);
	}
	// -------------------------------------------
	/*
		From the BasicItem class
		-------------------------------------------
	*/
	/**
		Always return FALSE.
		It is very seldom a child item is referenced by some other item than
		the parent item.
	*/
	public boolean isUsed()
		throws BaseException
	{
		return false;
	}
	// -------------------------------------------
	/*
		From the ChildItem class
		-------------------------------------------
	*/
	SharedData getSharedParent()
	{
		return getData().getParent();
	}
	// -------------------------------------------

	/**
		Get the parent AnyItem this child item belongs to.
		@return The <code>AnyItem</code> item
		@throws PermissionDeniedException If the logged in user doesn't have 
			{@link Permission#READ} permission
		@throws BaseException If there is another error
	*/
	public AnyItem getParent()
		throws PermissionDeniedException, BaseException
	{
		return getDbControl().getItem(AnyItem.class, getData().getParent());
	}
	/**
		Set the parent AnyItem this child item belongs to. Can only be set 
		on a new item.
		@throws InvalidDataException If the parent is null
	*/
	void setParent(AnyItem parent)
		throws PermissionDeniedException, InvalidDataException
	{
		checkPermission(Permission.WRITE);
		if (parent == null) throw new InvalidUseOfNullException("parent");
		getData().setParent(parent.getData());
	}

}