/*
 * 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.infstr.services;

import org.hibernate.Criteria;
import org.hibernate.Query;

import java.util.List;

public class Page {

	final private List results;
	final private Integer pageSize;
	final private int pageNumber;

	/**
	 * @param query Hibernate Query object that is executed to obtain list
	 * @param pageNumber The page number
	 * @param pageSize No of records to be returned. If this parameter is null, all the records are returned. The page parameter will be ignored in this case.
	 */
	public Page(final Query query, Integer pageNumber, final Integer pageSize) {
		if (pageNumber < 1) {
			pageNumber = 1;
		}

		this.pageNumber = pageNumber;
		if (pageSize != null && pageSize > 0) {
			query.setFirstResult((pageNumber - 1) * pageSize);
			query.setMaxResults(pageSize + 1);
			this.pageSize = pageSize;
		} else {
			this.pageSize = -1;
		}
		this.results = query.list();
	}

	/**
	 * @param criteria Hibernate Criteria object that is executed to obtain list
	 * @param pageNumber The page number
	 * @param pageSize No of records to be returned. If this parameter is null, all the records are returned. The page parameter will be ignored in this case.
	 */
	public Page(final Criteria criteria, Integer pageNumber, final Integer pageSize) {
		if (pageNumber < 1) {
			pageNumber = 1;
		}

		this.pageNumber = pageNumber;

		if (pageSize != null && pageSize > 0) {
			criteria.setFirstResult((pageNumber - 1) * pageSize);
			criteria.setMaxResults(pageSize + 1);
			this.pageSize = pageSize;
		} else {
			this.pageSize = -1;
		}
		this.results = criteria.list();
	}

	public boolean isNextPage() {
		return (this.pageSize != -1 && this.results.size() > this.pageSize);
	}

	public boolean isPreviousPage() {
		return this.pageNumber > 0;
	}

	public List getList() {
		return isNextPage() ? this.results.subList(0, this.pageSize) : this.results;
	}

	public Integer getPageNo() {
		return this.pageNumber;
	}

	public Integer getPageSize() {
		return this.pageSize;
	}
}