/*
 * eXist Open Source Native XML Database
 * Copyright (C) 2001-2010 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.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.exist.EXistException;
import org.exist.dom.QName;
import org.exist.security.Account;
import org.exist.security.PermissionDeniedException;
import org.exist.security.SecurityManager;
import org.exist.security.Subject;
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.functions.securitymanager.GroupMembershipFunction;
import org.exist.xquery.value.BooleanValue;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;

/**
 * @author Adam Retter <adam@existsolutions.com>
 * @author <a href="mailto:shabanovd@gmail.com">Dmitriy Shabanov</a>
 */
@Deprecated
public class XMLDBRemoveUserFromGroup extends BasicFunction {

    protected static final Logger logger = LogManager.getLogger(XMLDBRemoveUserFromGroup.class);

    public final static FunctionSignature signature = new FunctionSignature(
            new QName("remove-user-from-group", XMLDBModule.NAMESPACE_URI, XMLDBModule.PREFIX),
            "Remove a user from a group. $user is the username. $group is the group name" + XMLDBModule.NEED_PRIV_USER,
            new SequenceType[]{
                new FunctionParameterSequenceType("user", Type.STRING, Cardinality.EXACTLY_ONE, "The user name"),
                new FunctionParameterSequenceType("group", Type.STRING, Cardinality.EXACTLY_ONE, "The group name")
            },
            new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.EXACTLY_ONE, "true() or false() indicating the outcome of the operation"),
            GroupMembershipFunction.FNS_REMOVE_GROUP_MEMBER
    );

    /**
     * @param context
     */
    public XMLDBRemoveUserFromGroup(XQueryContext context) {
        super(context, signature);
    }

    /*
     * (non-Javadoc)
     *
     * @see org.exist.xquery.Expression#eval(org.exist.dom.persistent.DocumentSet,
     *         org.exist.xquery.value.Sequence, org.exist.xquery.value.Item)
     */
    @Override
    public Sequence eval(Sequence args[], Sequence contextSequence) throws XPathException {

        if("guest".equals(context.getSubject().getName())) {
            final XPathException xPathException = 
            	new XPathException(this, "Permission denied, calling account '" + context.getSubject().getName() + "' must be an authenticated user to call this function.");
            logger.error("Invalid account", xPathException);
            throw xPathException;
        }

        final String userName = args[0].getStringValue();
        final String groupName = args[1].getStringValue();

        logger.info("Attempting to remove user '" + userName + "' from group '" + groupName + "'");

        try {

            final SecurityManager sm = context.getBroker().getBrokerPool().getSecurityManager();

            final Account account = sm.getAccount(userName);

            account.remGroup(groupName);

            //TEMP - ESCALATE TO DBA :-(
            //START TEMP - Whilst we can remove the group from the user
            //we cannot update the user because we do not have sufficient permissions
            //in the real world we should not be able to do either. The modelling of group
            //membership as a concern of user data is wrong! Should follow Unix approach.
            //see XMLDBAddUserToGroup also
            try {
                //escalate
                context.getBroker().pushSubject(sm.getSystemSubject());

                //perform action
                sm.updateAccount(account);
            } finally {
                context.getBroker().popSubject();
            }
            //END TEMP

            return BooleanValue.TRUE;

        } catch(final PermissionDeniedException pde) {
			throw new XPathException(this, 
					"Permission denied, calling account '" + context.getSubject().getName()
					+ "' do not authorize to call this function.");
        } catch(final EXistException exe) {
            logger.error("Failed to remove user '" + userName + "' from group '" + groupName + "'", exe);
        } finally {
       }

        return BooleanValue.FALSE;
    }
}