/*
 Copyright (C) 2008 Srinivas Hasti

 This source code is release under the BSD License.

 This file is part of JQuantLib, a free-software/open-source library
 for financial quantitative analysts and developers - http://jquantlib.org/

 JQuantLib is free software: you can redistribute it and/or modify it
 under the terms of the JQuantLib license.  You should have received a
 copy of the license along with this program; if not, please email
 . The license is also available online at
 .

 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 license for more details.

 JQuantLib is based on QuantLib. http://quantlib.org/
 When applicable, the original copyright notice follows this notice.
 */

package org.jquantlib.time;

import org.jquantlib.QL;

/**
 * To convert short and long format string representations
 * to period object.
 * @author Srinivas Hasti
 */
// TODO: code review :: please verify against QL/C++ code
public final class PeriodParser {

	/**
	 * To convert the string to Period.
	 * @param str
	 * @return period derived from str
	 */
	public static Period parse(final String str) {
		TimeUnit units = null;
		int index = -1;
		if ((index = str.indexOf('d')) > 0 || (index = str.indexOf('D')) > 0) {
			units = TimeUnit.Days;
		} else if ((index = str.indexOf('w')) > 0 || (index = str.indexOf('W')) > 0) {
			units = TimeUnit.Weeks;
		} else if ((index = str.indexOf('m')) > 0 || (index = str.indexOf('M')) > 0) {
			units = TimeUnit.Months;
		} else if ((index = str.indexOf('y')) > 0 || (index = str.indexOf('Y')) > 0) {
			units = TimeUnit.Years;
		}
		QL.require (index != -1, "Invalid string passed to period parser");
		final String intstr = str.substring(0, index).trim();
		return new Period(Integer.parseInt(intstr), units);
	}
}