/*
 * eXist Open Source Native XML Database
 * Copyright (C) 2004-2009 The eXist Project
 * http://exist-db.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2
 * 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 Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *  
 *  $Id$
 */
package org.exist.xquery.functions.xmldb;

import org.apache.log4j.Logger;

import org.exist.dom.QName;
import org.exist.security.Permission;
import org.exist.security.PermissionFactory;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.IntegerValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.StringValue;
import org.exist.xquery.value.Type;

/**
 * @author wolf
 */
public class XMLDBPermissionsToString extends BasicFunction {
	protected static final Logger logger = Logger.getLogger(XMLDBPermissionsToString.class);
	public final static FunctionSignature signature =
		new FunctionSignature(
			new QName("permissions-to-string", XMLDBModule.NAMESPACE_URI, XMLDBModule.PREFIX),
			"Formats the resource or collection permissions, $permissions, passed as an integer " +
			"value into a string. The returned string shows the permissions following " +
			"the Unix conventions, i.e. all permissions set is returned as " +
			"rwurwurwu, where the first three chars are for user permissions, " +
			"followed by group and other users. 'r' denotes read, 'w' write and 'u' update " +
			"permissions.",
			new SequenceType[] {
                new FunctionParameterSequenceType("permissions", Type.INTEGER, Cardinality.EXACTLY_ONE, "The permissions in xs:integer format")
			},
			new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE, "the permissions as string 'rwu' for, user, group and other"));
	
	/**
	 * @param context
	 */
	public XMLDBPermissionsToString(XQueryContext context) {
		super(context, signature);
	}

	/* (non-Javadoc)
	 * @see org.exist.xquery.BasicFunction#eval(org.exist.xquery.value.Sequence[], org.exist.xquery.value.Sequence)
	 */
	public Sequence eval(Sequence[] args, Sequence contextSequence)
			throws XPathException {
		int value = ((IntegerValue)args[0].itemAt(0)).getInt();
		Permission perm = PermissionFactory.getPermission(value);
		return new StringValue(perm.toString());
	}

}