/*
	Todo Otimizar caulculo de timezone
	Objeto Date.toString() retorna a data com inserção do offset
	Objeto Date.getTime() retorna a data sem inserção do offset
*/

var objTime = DataLayer.dispatch( "timezones" );
Timezone = {
  
	daylightSaving: parseInt( objTime.isDaylightSaving ),

	timezones: objTime.timezones,	  
	timezone: function( tzId ){

		return this.timezones[ tzId || User.preferences.timezone ];

	},

	compareTZID: function( fromTZID, toTZID ){

		return( this.timezones[ fromTZID ] === this.timezones[ toTZID ] );

	},

	checkTimezoneCalendar: function(idCalendar, tzId){

		return idCalendar && this.compareTZID( DataLayer.get('calendar', idCalendar).timezone, tzId );

	},
	
	setDateTimezone: function (date, tzId, idCalendar){
	
		if( !!!tzId || this.checkTimezoneCalendar(idCalendar, tzId) )
			return date;

		var timezone = this.timezone( tzId );

		var timezoneOffset = parseInt(timezone.substr(2)) - this.daylightSaving * 100;

		var timeCurrent = parseInt((date.getTimezoneOffset()/60)+'00') * ( ( timezone.charAt(0) != date.getUTCOffset().charAt(0) )? 1 : -1 );

		var times = timezoneOffset + timeCurrent;

		if(times == 0)
			return date;		
		else if(times > 0)
			return date.setTimezoneOffset('-0'+(times));
		else
			return date.setTimezoneOffset('+0'+((times * -1)));
	},

	getDateTimezone: function(date, tzId, recursive){

		var timezone = this.timezone( tzId );

		if(!timezone)
			return date;

		var currentTimezone = parseInt((date.getTimezoneOffset()/60)+'00');

		var timezoneOffset = parseInt(timezone.substr(2)) - this.daylightSaving * 100;

		var times =  timezoneOffset - currentTimezone;

		if(times == 0){
			if((timezone.charAt(0) == date.getUTCOffset().charAt(0)) && recursive)
				return date.setTimezoneOffset( timezone.charAt(0)+'0'+(currentTimezone));

			return  date;
		}else if (times > 0)
			return date.setTimezoneOffset('+0'+(times));
		else{
			return date.setTimezoneOffset('-0'+((times * -1) + (currentTimezone * 2)));
		}
	},
	
	getDateUTC: function (date, tzId){

			var timezone = this.timezone( tzId ), currentTimezone = parseInt(timezone.substr(2)) - this.daylightSaving * 100;
			return(date.setTimezoneOffset(timezone.charAt(0)+'0'+currentTimezone));
	},

	createDateTimezone: function(date, tzId, idCalendar){			
		if(this.checkTimezoneCalendar(idCalendar, tzId))
			return this.getDateTimezone(date, tzId, true);

		var times = 0, timezone = this.timezone( tzId );
		
		if(timezone.charAt(0) == '+')
			times = parseInt(timezone.substr(2)) - parseInt((date.getTimezoneOffset()/60)+'00');
		else
			times = (parseInt(timezone.substr(2)) + parseInt((date.getTimezoneOffset()/60)+'00')) * (-1);
		if(times == 0)
			return date.setTimezoneOffset('0000');
		else if (times > 0)
			return date.setTimezoneOffset('+0'+times);
		else
			return date.setTimezoneOffset('-0'+(times * -1));
	}



}