/*
 * Copyright 2012-2017 Red Hat, Inc.
 *
 * This file is part of Thermostat.
 *
 * Thermostat 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 2, or (at your
 * option) any later version.
 *
 * Thermostat 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 Thermostat; see the file COPYING.  If not see
 * <http://www.gnu.org/licenses/>.
 *
 * Linking this code with other modules is making a combined work
 * based on this code.  Thus, the terms and conditions of the GNU
 * General Public License cover the whole combination.
 *
 * As a special exception, the copyright holders of this code give
 * you permission to link this code with independent modules to
 * produce an executable, regardless of the license terms of these
 * independent modules, and to copy and distribute the resulting
 * executable under terms of your choice, provided that you also
 * meet, for each linked independent module, the terms and conditions
 * of the license of that module.  An independent module is a module
 * which is not derived from or based on this code.  If you modify
 * this code, you may extend this exception to your version of the
 * library, but you are not obligated to do so.  If you do not wish
 * to do so, delete this exception statement from your version.
 */

package com.redhat.thermostat.web.server.auth;

import java.util.HashSet;
import java.util.Set;

import com.redhat.thermostat.storage.model.Pojo;
import com.redhat.thermostat.storage.query.Expression;
import com.redhat.thermostat.web.server.auth.FilterResult.ResultType;

abstract class AbstractFilter<T extends Pojo> implements StatementFilter<T> {

    private static final String ALL_ROLE_NAME = "ALL";
    protected final Set<BasicRole> userRoles;
    
    protected AbstractFilter(Set<BasicRole> userRoles) {
        this.userRoles = userRoles;
    }
    
    protected Set<String> getGranted(String prefix) {
        Set<String> allowedObjectsFromRoles = new HashSet<>();
        for (BasicRole r : userRoles) {
            if (r.getName().startsWith(prefix)) {
                String allowedVm = r.getName().substring(
                        prefix.length());
                if (!allowedVm.equals(ALL_ROLE_NAME)) {
                    allowedObjectsFromRoles.add(allowedVm);
                }
            }
        }
        return allowedObjectsFromRoles;
    }
    
    protected FilterResult allWithExpression(Expression parentExpression) {
        if (parentExpression != null) {
            FilterResult result = new FilterResult(
                    ResultType.QUERY_EXPRESSION);
            result.setFilterExpression(parentExpression);
            return result;
        } else {
            return new FilterResult(ResultType.ALL);
        }
    }
}