/*
 * Copyright (C) 2005 Luca Veltri - University of Parma - Italy
 * 
 * This file is part of MjSip (http://www.mjsip.org)
 * 
 * MjSip 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 of the License, or
 * (at your option) any later version.
 * 
 * MjSip 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 MjSip; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * 
 * Author(s):
 * Luca Veltri (luca.veltri@unipr.it)
 */

package org.zoolu.sip.header;

import org.zoolu.sip.provider.SipParser;
import org.zoolu.tools.Parser;
import java.util.Date;

/**
 * SIP Header Expires.
 * <p>
 * Note: for backward compatibility with legacy implementations the date format
 * is still supported although it has been deprecated in RFC 3261.
 */
public class ExpiresHeader extends SipDateHeader {


	public ExpiresHeader(String hvalue) {
		super(SipHeaders.Expires, hvalue);
	}

	/** Creates a new ExpiresHeader based on a Date value. */
	public ExpiresHeader(Date date) {
		super(SipHeaders.Expires, date);
	}

	/** Creates a new ExpiresHeader with delta-seconds as value. */
	public ExpiresHeader(int seconds) {
		super(SipHeaders.Expires, (String) null);
		value = String.valueOf(seconds);
	}

	public ExpiresHeader(Header hd) {
		super(hd);
	}

	/**
	 * Gets boolean value to indicate if expiry value of ExpiresHeader is in
	 * date format.
	 */
	public boolean isDate() {
		if (value.indexOf("GMT") >= 0)
			return true;
		return false;
	}

	/** Gets value of ExpiresHeader as delta-seconds */
	public int getDeltaSeconds() {
		int secs = -1;
		if (isDate()) {
			Date date = (new SipParser((new Parser(value)).getStringUnquoted()))
					.getDate();
			secs = (int) ((date.getTime() - System.currentTimeMillis()) / 1000);
			if (secs < 0)
				secs = 0;
		} else
			secs = (new SipParser(value)).getInt();

		return secs;
	}

	/** Gets value of ExpiresHeader as absolute date */
	public Date getDate() {
		Date date = null;
		if (isDate()) {
			date = (new SipParser((new Parser(value)).getStringUnquoted()))
					.getDate();
		} else {
			long secs = getDeltaSeconds();
			if (secs >= 0)
				date = new Date(System.currentTimeMillis() + secs * 1000);
		}
		return date;
	}

}
