/*
 * eGov suite of products aim to improve the internal efficiency,transparency,
 *    accountability and the service delivery of the government  organizations.
 *
 *     Copyright (C) <2015>  eGovernments Foundation
 *
 *     The updated version of eGov suite of products as by eGovernments Foundation
 *     is available at http://www.egovernments.org
 *
 *     This program 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
 *     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 General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program. If not, see http://www.gnu.org/licenses/ or
 *     http://www.gnu.org/licenses/gpl.html .
 *
 *     In addition to the terms of the GPL license to be adhered to in using this
 *     program, the following additional terms are to be complied with:
 *
 *         1) All versions of this program, verbatim or modified must carry this
 *            Legal Notice.
 *
 *         2) Any misrepresentation of the origin of the material is prohibited. It
 *            is required that all modified versions of this material be marked in
 *            reasonable ways as different from the original version.
 *
 *         3) This license does not grant any rights to any user of the program
 *            with regards to rights under trademark law for use of the trade names
 *            or trademarks of eGovernments Foundation.
 *
 *   In case of any queries, you can reach eGovernments Foundation at contact@egovernments.org.
 */

package org.egov.infra.persistence.utils;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.exception.SQLGrammarException;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import java.io.Serializable;
import java.sql.SQLException;

@Service
public class DBSequenceGenerator {
    public static final String NEXT_SEQ_SQL_QUERY = "SELECT nextval (:sequenceName) as nextval";

    @PersistenceContext
    private EntityManager entityManager;

    @Transactional(readOnly = true, propagation = Propagation.REQUIRES_NEW, noRollbackFor = SQLGrammarException.class)
    public Serializable createAndGetNextSequence(final String sequenceName) throws SQLException {
        Query query = entityManager.unwrap(Session.class).createSQLQuery("create sequence " + sequenceName);
        query.executeUpdate();

        query = entityManager.unwrap(Session.class).createSQLQuery(NEXT_SEQ_SQL_QUERY);
        query.setParameter("sequenceName", sequenceName);
        return (Serializable) query.uniqueResult();
    }
}