/* 
 *  Copyright (C) 2000 - 2008 TagServlet Ltd
 *
 *  This file is part of Open BlueDragon (OpenBD) CFML Server Engine.
 *  
 *  OpenBD is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  Free Software Foundation,version 3.
 *  
 *  OpenBD 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 OpenBD.  If not, see http://www.gnu.org/licenses/
 *  
 *  Additional permission under GNU GPL version 3 section 7
 *  
 *  If you modify this Program, or any covered work, by linking or combining 
 *  it with any of the JARS listed in the README.txt (or a modified version of 
 *  (that library), containing parts covered by the terms of that JAR, the 
 *  licensors of this Program grant you additional permission to convey the 
 *  resulting work. 
 *  README.txt @ http://www.openbluedragon.org/license/README.txt
 *  
 *  http://www.openbluedragon.org/
 */

package com.naryx.tagfusion.expression.function;

import java.util.Calendar;

import com.naryx.tagfusion.cfm.engine.cfArgStructData;
import com.naryx.tagfusion.cfm.engine.cfData;
import com.naryx.tagfusion.cfm.engine.cfNumberData;
import com.naryx.tagfusion.cfm.engine.cfSession;
import com.naryx.tagfusion.cfm.engine.cfmRunTimeException;

public class week extends functionBase {

	private static final long serialVersionUID = 1L;

	public week() {
		min = max = 1;
		setNamedParams( new String[]{ "date" } );
	}

	public String[] getParamInfo(){
		return new String[]{
			"date"
		};
	}
  
	public java.util.Map getInfo(){
		return makeInfo(
				"date", 
				"Returns the week number in the year of the date referenced", 
				ReturnType.NUMERIC );
	}
 
	public cfData execute(cfSession _session, cfArgStructData argStruct ) throws cfmRunTimeException {
		// note: need to use the UK locale in order for week to start on a Monday
		// (it's Sunday if we use US)
		Calendar calendar =getNamedParam( argStruct, "date" ).getDateData().getCalendar();

		// With JDK 1.3 and 1.4, MinimalDaysInFirstWeek defaults to 1 while with JDK
		// 1.5 it defaults to 4.
		// We'll set it to 1 so BD will behave the same with all versions of the JDK
		// and match CFMX.
		// Note that setting it to 4 would cause it to match the ISO 8601 definition
		// for week of year.
		calendar.setMinimalDaysInFirstWeek(1);

		int week = calendar.get(Calendar.WEEK_OF_YEAR);
		if (week == 1 && calendar.get(Calendar.MONTH) == Calendar.DECEMBER) {
			if (calendar.get(Calendar.DAY_OF_MONTH) == 31 && calendar.getFirstDayOfWeek() == Calendar.SUNDAY && calendar.get(Calendar.YEAR) % 28 == 12) {
				week = 54;
			} else {
				week = 53;
			}
		}
		return new cfNumberData(week);
	}
}