/**
 * ============LICENSE_START====================================================
 * org.onap.aaf
 * ===========================================================================
 * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
 * ===========================================================================
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * ============LICENSE_END====================================================
 *
 */

package org.onap.aaf.cadi.util;

public class FQI {
    /**
     * Take a Fully Qualified User, and get a Namespace from it.
     * @param fqi
     * @return
     */
    public final static String reverseDomain(final String fqi) {
        StringBuilder sb = null;
        String[] split = Split.split('.',fqi);
        int at;
        for (int i=split.length-1;i>=0;--i) {
            if (sb == null) {
                sb = new StringBuilder();
            } else {
                sb.append('.');
            }

            if ((at = split[i].indexOf('@'))>0) {
                sb.append(split[i].subSequence(at+1, split[i].length()));
            } else {
                sb.append(split[i]);
            }
        }

        return sb==null?"":sb.toString();
    }

}