/*
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	Copyright(c) 2005 Adobe Systems Incorporated. All rights reserved.
	
	Please read this Source Code License Agreement carefully before using
	the source code.
	
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*/

package com.adobe.utils
{
	import com.adobe.utils.ArrayUtil;
	import mx.formatters.DateBase;

	/**
	* 	Class that contains static utility methods for manipulating and working
	*	with Dates.
	* 
	* 	@langversion ActionScript 3.0
	*	@playerversion Flash 9.0
	*	@tiptext
	*/	
	public class DateUtil
	{
	
		/**
		*	Returns the English Short Month name (3 letters) for the Month that
		*	the Date represents.  	
		* 
		* 	@param d The Date instance whose month will be used to retrieve the
		*	short month name.
		* 
		* 	@return An English 3 Letter Month abbreviation.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*
		*	@see SHORT_MONTH
		*/	
		public static function getShortMonthName(d:Date):String
		{
			return DateBase.monthNamesShort[d.getMonth()];
		}

		/**
		*	Returns the index of the month that the short month name string
		*	represents. 	
		* 
		* 	@param m The 3 letter abbreviation representing a short month name.
		*
		*	@param Optional parameter indicating whether the search should be case
		*	sensitive
		* 
		* 	@return A int that represents that month represented by the specifed
		*	short name.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*
		*	@see SHORT_MONTH
		*/	
		public static function getShortMonthIndex(m:String):int
		{
			return DateBase.monthNamesShort.indexOf(m);
		}
		
		/**
		*	Returns the English full Month name for the Month that
		*	the Date represents.  	
		* 
		* 	@param d The Date instance whose month will be used to retrieve the
		*	full month name.
		* 
		* 	@return An English full month name.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*
		*	@see FULL_MONTH
		*/	
		public static function getFullMonthName(d:Date):String
		{
			return DateBase.monthNamesLong[d.getMonth()];	
		}

		/**
		*	Returns the index of the month that the full month name string
		*	represents. 	
		* 
		* 	@param m A full month name.
		* 
		* 	@return A int that represents that month represented by the specifed
		*	full month name.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*
		*	@see FULL_MONTH
		*/	
		public static function getFullMonthIndex(m:String):int
		{
			return DateBase.monthNamesLong.indexOf(m);
		}

		/**
		*	Returns the English Short Day name (3 letters) for the day that
		*	the Date represents.  	
		* 
		* 	@param d The Date instance whose day will be used to retrieve the
		*	short day name.
		* 
		* 	@return An English 3 Letter day abbreviation.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*
		*	@see SHORT_DAY
		*/	
		public static function getShortDayName(d:Date):String
		{
			return DateBase.dayNamesShort[d.getDay()];	
		}
		
		/**
		*	Returns the index of the day that the short day name string
		*	represents. 	
		* 
		* 	@param m A short day name.
		* 
		* 	@return A int that represents that short day represented by the specifed
		*	full month name.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*
		*	@see SHORT_DAY
		*/			
		public static function getShortDayIndex(d:String):int
		{
			return DateBase.dayNamesShort.indexOf(d);
		}

		/**
		*	Returns the English full day name for the day that
		*	the Date represents.  	
		* 
		* 	@param d The Date instance whose day will be used to retrieve the
		*	full day name.
		* 
		* 	@return An English full day name.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*
		*	@see FULL_DAY
		*/	
		public static function getFullDayName(d:Date):String
		{
			return DateBase.dayNamesLong[d.getDay()];	
		}		

		/**
		*	Returns the index of the day that the full day name string
		*	represents. 	
		* 
		* 	@param m A full day name.
		* 
		* 	@return A int that represents that full day represented by the specifed
		*	full month name.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*
		*	@see FULL_DAY
		*/		
		public static function getFullDayIndex(d:String):int
		{
			return DateBase.dayNamesLong.indexOf(d);
		}

		/**
		*	Returns a two digit representation of the year represented by the 
		*	specified date.
		* 
		* 	@param d The Date instance whose year will be used to generate a two
		*	digit string representation of the year.
		* 
		* 	@return A string that contains a 2 digit representation of the year.
		*	Single digits will be padded with 0.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*/	
		public static function getShortYear(d:Date):String
		{
			var dStr:String = String(d.getFullYear());
			
			if(dStr.length < 3)
			{
				return dStr;
			}

			return (dStr.substr(dStr.length - 2));
		}

		/**
		*	Compares two dates and returns an integer depending on their relationship.
		*
		*	Returns -1 if d1 is greater than d2.
		*	Returns 1 if d2 is greater than d1.
		*	Returns 0 if both dates are equal.
		* 
		* 	@param d1 The date that will be compared to the second date.
		*	@param d2 The date that will be compared to the first date.
		* 
		* 	@return An int indicating how the two dates compare.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*/	
		public static function compareDates(d1:Date, d2:Date):int
		{
			var d1ms:Number = d1.getTime();
			var d2ms:Number = d2.getTime();
			
			if(d1ms > d2ms)
			{
				return -1;
			}
			else if(d1ms < d2ms)
			{
				return 1;
			}
			else
			{
				return 0;
			}
		}

		/**
		*	Returns a short hour (0 - 12) represented by the specified date.
		*
		*	If the hour is less than 12 (0 - 11 AM) then the hour will be returned.
		*
		*	If the hour is greater than 12 (12 - 23 PM) then the hour minus 12
		*	will be returned.
		* 
		* 	@param d1 The Date from which to generate the short hour
		* 
		* 	@return An int between 0 and 13 ( 1 - 12 ) representing the short hour.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*/	
		public static function getShortHour(d:Date):int
		{
			var h:int = d.hours;
			
			if(h == 0 || h == 12)
			{
				return 12;
			}
			else if(h > 12)
			{
				return h - 12;
			}
			else
			{
				return h;
			}
		}
		
		/**
		*	Returns a string indicating whether the date represents a time in the
		*	ante meridiem (AM) or post meridiem (PM).
		*
		*	If the hour is less than 12 then "AM" will be returned.
		*
		*	If the hour is greater than 12 then "PM" will be returned.
		* 
		* 	@param d1 The Date from which to generate the 12 hour clock indicator.
		* 
		* 	@return A String ("AM" or "PM") indicating which half of the day the 
		*	hour represents.
		*
		* 	@langversion ActionScript 3.0
		*	@playerversion Flash 9.0
		*	@tiptext
		*/	
		public static function getAMPM(d:Date):String
		{
			return (d.hours > 11)? "PM" : "AM";
		}

		/**
		* Parses dates that conform to RFC822 into Date objects. This method also
		* supports four-digit years (not supported in RFC822), but two-digit years
		* (referring to the 20th century) are fine, too.
		*
		* This function is useful for parsing RSS .91, .92, and 2.0 dates.
		*
		* @param str
		*
		* @returns
		*
		* @langversion ActionScript 3.0
		* @playerversion Flash 9.0
		* @tiptext
		*
		* @see http://asg.web.cmu.edu/rfc/rfc822.html
		*/		
		public static function parseRFC822(str:String):Date
		{
            var finalDate:Date;
			try
			{
				var dateParts:Array = str.split(" ");
				var day:String = null;
				
				if (dateParts[0].search(/\d/) == -1)
				{
					day = dateParts.shift().replace(/\W/, "");
				}
				
				var date:Number = Number(dateParts.shift());
				var month:Number = Number(DateUtil.getShortMonthIndex(dateParts.shift()));
				var year:Number = Number(dateParts.shift());
				var timeParts:Array = dateParts.shift().split(":");
				var hour:Number = int(timeParts.shift());
				var minute:Number = int(timeParts.shift());
				var second:Number = (timeParts.length > 0) ? int(timeParts.shift()): 0;
	
				var milliseconds:Number = Date.UTC(year, month, date, hour, minute, second, 0);
	
				var timezone:String = dateParts.shift();
				var offset:Number = 0;

				if (timezone.search(/\d/) == -1)
				{
					switch(timezone)
					{
						case "UT":
							offset = 0;
							break;
						case "UTC":
							offset = 0;
							break;
						case "GMT":
							offset = 0;
							break;
						case "EST":
							offset = (-5 * 3600000);
							break;
						case "EDT":
							offset = (-4 * 3600000);
							break;
						case "CST":
							offset = (-6 * 3600000);
							break;
						case "CDT":
							offset = (-5 * 3600000);
							break;
						case "MST":
							offset = (-7 * 3600000);
							break;
						case "MDT":
							offset = (-6 * 3600000);
							break;
						case "PST":
							offset = (-8 * 3600000);
							break;
						case "PDT":
							offset = (-7 * 3600000);
							break;
						case "Z":
							offset = 0;
							break;
						case "A":
							offset = (-1 * 3600000);
							break;
						case "M":
							offset = (-12 * 3600000);
							break;
						case "N":
							offset = (1 * 3600000);
							break;
						case "Y":
							offset = (12 * 3600000);
							break;
						default:
							offset = 0;
					}
				}
				else
				{
					var multiplier:Number = 1;
					var oHours:Number = 0;
					var oMinutes:Number = 0;
					if (timezone.length != 4)
					{
						if (timezone.charAt(0) == "-")
						{
							multiplier = -1;
						}
						timezone = timezone.substr(1, 4);
					}
					oHours = Number(timezone.substr(0, 2));
					oMinutes = Number(timezone.substr(2, 2));
					offset = (((oHours * 3600000) + (oMinutes * 60000)) * multiplier);
				}

				finalDate = new Date(milliseconds - offset);

				if (finalDate.toString() == "Invalid Date")
				{
					throw new Error("This date does not conform to RFC822.");
				}
			}
			catch (e:Error)
			{
				var eStr:String = "Unable to parse the string [" +str+ "] into a date. ";
				eStr += "The internal error was: " + e.toString();
				throw new Error(eStr);
			}
            return finalDate;
		}
	     
		/**
		* Returns a date string formatted according to RFC822.
		*
		* @param d
		*
		* @returns
		*
		* @langversion ActionScript 3.0
		* @playerversion Flash 9.0
		* @tiptext
		*
		* @see http://asg.web.cmu.edu/rfc/rfc822.html
		*/	
		public static function toRFC822(d:Date):String
		{
			var date:Number = d.getUTCDate();
			var hours:Number = d.getUTCHours();
			var minutes:Number = d.getUTCMinutes();
			var seconds:Number = d.getUTCSeconds();
			var sb:String = new String();
			sb += DateBase.dayNamesShort[d.getUTCDay()];
			sb += ", ";
			
			if (date < 10)
			{
				sb += "0";
			}
			sb += date;
			sb += " ";
			//sb += DateUtil.SHORT_MONTH[d.getUTCMonth()];
			sb += DateBase.monthNamesShort[d.getUTCMonth()];
			sb += " ";
			sb += d.getUTCFullYear();
			sb += " ";
			if (hours < 10)
			{			
				sb += "0";
			}
			sb += hours;
			sb += ":";
			if (minutes < 10)
			{			
				sb += "0";
			}
			sb += minutes;
			sb += ":";
			if (seconds < 10)
			{			
				sb += "0";
			}
			sb += seconds;
			sb += " GMT";
			return sb;
		}
	     
		/**
		* Parses dates that conform to the W3C Date-time Format into Date objects.
		*
		* This function is useful for parsing RSS 1.0 and Atom 1.0 dates.
		*
		* @param str
		*
		* @returns
		*
		* @langversion ActionScript 3.0
		* @playerversion Flash 9.0
		* @tiptext
		*
		* @see http://www.w3.org/TR/NOTE-datetime
		*/		     
		public static function parseW3CDTF(str:String):Date
		{
            var finalDate:Date;
			try
			{
				var dateStr:String = str.substring(0, str.indexOf("T"));
				var timeStr:String = str.substring(str.indexOf("T")+1, str.length);
				var dateArr:Array = dateStr.split("-");
				var year:Number = Number(dateArr.shift());
				var month:Number = Number(dateArr.shift());
				var date:Number = Number(dateArr.shift());
				
				var multiplier:Number;
				var offsetHours:Number;
				var offsetMinutes:Number;
				var offsetStr:String;
				
				if (timeStr.indexOf("Z") != -1)
				{
					multiplier = 1;
					offsetHours = 0;
					offsetMinutes = 0;
					timeStr = timeStr.replace("Z", "");
				}
				else if (timeStr.indexOf("+") != -1)
				{
					multiplier = 1;
					offsetStr = timeStr.substring(timeStr.indexOf("+")+1, timeStr.length);
					offsetHours = Number(offsetStr.substring(0, offsetStr.indexOf(":")));
					offsetMinutes = Number(offsetStr.substring(offsetStr.indexOf(":")+1, offsetStr.length));
					timeStr = timeStr.substring(0, timeStr.indexOf("+"));
				}
				else // offset is -
				{
					multiplier = -1;
					offsetStr = timeStr.substring(timeStr.indexOf("-")+1, timeStr.length);
					offsetHours = Number(offsetStr.substring(0, offsetStr.indexOf(":")));
					offsetMinutes = Number(offsetStr.substring(offsetStr.indexOf(":")+1, offsetStr.length));
					timeStr = timeStr.substring(0, timeStr.indexOf("-"));
				}
				var timeArr:Array = timeStr.split(":");
				var hour:Number = Number(timeArr.shift());
				var minutes:Number = Number(timeArr.shift());
				var secondsArr:Array = (timeArr.length > 0) ? String(timeArr.shift()).split(".") : null;
				var seconds:Number = (secondsArr != null && secondsArr.length > 0) ? Number(secondsArr.shift()) : 0;
				var milliseconds:Number = (secondsArr != null && secondsArr.length > 0) ? Number(secondsArr.shift()) : 0;
				var utc:Number = Date.UTC(year, month-1, date, hour, minutes, seconds, milliseconds);
				var offset:Number = (((offsetHours * 3600000) + (offsetMinutes * 60000)) * multiplier);
				finalDate = new Date(utc - offset);
	
				if (finalDate.toString() == "Invalid Date")
				{
					throw new Error("This date does not conform to W3CDTF.");
				}
			}
			catch (e:Error)
			{
				var eStr:String = "Unable to parse the string [" +str+ "] into a date. ";
				eStr += "The internal error was: " + e.toString();
				throw new Error(eStr);
			}
            return finalDate;
		}
	     
		/**
		* Returns a date string formatted according to W3CDTF.
		*
		* @param d
		* @param includeMilliseconds Determines whether to include the
		* milliseconds value (if any) in the formatted string.
		*
		* @returns
		*
		* @langversion ActionScript 3.0
		* @playerversion Flash 9.0
		* @tiptext
		*
		* @see http://www.w3.org/TR/NOTE-datetime
		*/		     
		public static function toW3CDTF(d:Date,includeMilliseconds:Boolean=false):String
		{
			var date:Number = d.getUTCDate();
			var month:Number = d.getUTCMonth();
			var hours:Number = d.getUTCHours();
			var minutes:Number = d.getUTCMinutes();
			var seconds:Number = d.getUTCSeconds();
			var milliseconds:Number = d.getUTCMilliseconds();
			var sb:String = new String();
			
			sb += d.getUTCFullYear();
			sb += "-";
			
			//thanks to "dom" who sent in a fix for the line below
			if (month + 1 < 10)
			{
				sb += "0";
			}
			sb += month + 1;
			sb += "-";
			if (date < 10)
			{
				sb += "0";
			}
			sb += date;
			sb += "T";
			if (hours < 10)
			{
				sb += "0";
			}
			sb += hours;
			sb += ":";
			if (minutes < 10)
			{
				sb += "0";
			}
			sb += minutes;
			sb += ":";
			if (seconds < 10)
			{
				sb += "0";
			}
			sb += seconds;
			if (includeMilliseconds && milliseconds > 0)
			{
				sb += ".";
				sb += milliseconds;
			}
			sb += "-00:00";
			return sb;
		}
	}
}