From Wikipedia, the free encyclopedia

-- This module powers {{countdown-ymd}}.

require('strict')



local p = {}

local static_text = {

	'eventtime' = 'Time to event:',

	'begins' = 'Event begins in',												-- when |duration= is set

	'ends' = 'Event ends in',													-- when |duration= is set

	'ended' = 'Event has ended.',												-- when |duration= is set

	'passed' = 'Event time has passed.',

	'invalid' = '<span style="font-size:100%" class="error">Error: invalid date and/or time</span>',

	}



local getArgs = require('Module:Arguments').getArgs



--[[--------------------------< F O R M A T _ U N I T >--------------------------------------------------------



Concatenates a singular or plural label to a time/date unit: unit label or unit labels.  If unit is 0 or less, returns nil



]]



local function format_unit (unit, label)

	if 1 > unit then															-- less than one so don't display

		return nil;																-- return nil so the result of this call isn't stuffed into results table by table.insert

	elseif 1 == unit then

		return unit .. ' ' .. label;											-- only one unit so return singular label

	else

		return unit .. ' ' .. label .. 's';										-- multiple units so return plural label

	end

end





--[[--------------------------< D U R A T I O N >--------------------------------------------------------------



Returns duration of event in seconds.  If the units are not defined, assumes seconds.  If the units are

defined but not one of day, days, hour, hours, minute, minutes, second, seconds then returns zero.



|duration=<number><space><unit>



TODO: Why are we even considering seconds and minutes?  Would it be better to specify and end time?



]]



local function duration (duration)

	local number, unit = duration:match ('(%d+)%s+(%a*)');

	

	if not number then

		return 0;																-- duration not properly specified

	elseif not unit then

		return number;															-- unit not defined, assume seconds

	end

	

	if unit:match ('days?') then

		return number * 86400;

	elseif unit:match ('hours?') then

		return number * 3600;

	elseif unit:match ('minutes?') then

		return number * 60;

	elseif unit:match ('seconds?') then

		return number;

	else

		return 0;																-- unknown unit

	end

end



--[[--------------------------< U T C _ O F F S E T >----------------------------------------------------------



Returns offset from UTC in seconds.  If 'utc offset' parameter is out of range or malformed, returns 0.



TODO: Return a success/fail flag so we can emit an error message?



]]



local function utc_offset (offset)

	local sign, utc_offset_hr, utc_offset_min;

	

	if offset:match('^[%+%-]%d%d:%d%d$') then									-- formal style: sign, hours colon minutes all required

		sign, utc_offset_hr, utc_offset_min = offset:match('^([%+%-])(%d%d):(%d%d)$');

	elseif offset:match('^[%+%-]?%d?%d:?%d%d$') then							-- informal: sign and colon optional, 1- or 2-digit hours, and minutes 

		sign, utc_offset_hr, utc_offset_min = offset:match('^([%+%-]?)(%d?%d):?(%d%d)$');

	elseif offset:match('^[%+%-]?%d?%d$') then									-- informal: sign optional, 1- or 2-digit hours only

		sign, utc_offset_hr = offset:match('^([%+%-]?)(%d?%d)$');

		utc_offset_min = 0;														-- because not included in parameter, set it to 0 minutes

	else

		return 0;																-- malformed so return 0 seconds

	end

	

	utc_offset_hr = tonumber (utc_offset_hr);

	utc_offset_min = tonumber (utc_offset_min);

	

	if 12 < utc_offset_hr or 59 < utc_offset_min then							-- hour and minute range checks

		return 0;

	end

	

	if '-' == sign then

		sign = -1;																-- negative west offset

	else

		sign = 1;																-- + or sign omitted east offset

	end

	utc_offset_hr = sign * (utc_offset_hr * 3600);								-- utc offset hours * seconds/hour

	utc_offset_min = sign * (utc_offset_min * 60);								-- utc offset minutes * seconds/minute

	return utc_offset_hr + utc_offset_min;										-- return the UTC offset adjustment in seconds

end





--[[--------------------------< G E T _ D A Y S _ I N _ M O N T H >--------------------------------------------



Returns the number of days in the month where month is a number 1–12 and year is four-digit Gregorian calendar.

Accounts for leap year.



]]



local function get_days_in_month (year, month)

	local days_in_month = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

	

	year = tonumber (year);														-- force these to be numbers just in case

	month = tonumber (month);



	if (2 == month) then														-- if February

		if (0 == (year%4) and (0 ~= (year%100) or 0 == (year%400))) then		-- is year a leap year?

			return 29;															-- if leap year then 29 days in February

		end

	end

	return days_in_month month];

end



--[[--------------------------< D I F F _ T I M E >------------------------------------------------------------



calculates the difference between two times; returns a table of the differences in diff.hour, diff.min, and diff.sec



]]



local function diff_time (a, b)

	local diff = {}

	diff.sec = a.sec - b. sec;

	if diff.sec < 0 then

		diff.sec = diff.sec + 60;												-- borrow from minutes

		a.min = a.min - 1;

		if a.min < 0 then

			a.min = a.min + 60;													-- borrow from hours

			a.hour = a.hour - 1;

		end

	end

	diff.min = a.min - b.min;

	if diff.min < 0 then

		diff.min = diff.min + 60;												-- borrow from hours

		a.hour = a.hour - 1;

	end

	diff.hour = a.hour - b.hour;

	return diff;

end



--[[--------------------------< D I F F _ D A T E >------------------------------------------------------------



calculates the difference between two dates; returns a table of the difference in diff.year, diff.month, and diff.day



]]



local function diff_date (a, b)

	local diff = {}

	diff.day = a.day - b.day;

	if diff.day < 0 then

		a.month = a.month - 1;

		if a.month < 1 then	

			a.year = a.year - 1;												-- borrow a month from years

			a.month = a.month + 12;

		end

		diff.day = diff.day + get_days_in_month (a.year, a.month);				-- borrow all of the days from the *previous* month

	end



	diff.month = a.month - b.month;

	if diff.month < 0 then

		a.year = a.year - 1;													-- borrow a month from years

		diff.month = diff.month + 12;

	end

	diff.year = a.year - b.year;

	return diff;

end



--[[--------------------------< I S _ V A L I D _ D A T E _ T I M E >------------------------------------------



Validate date/time.  Also, determine if we have all of the necessary date/time componants.  Minimal required

date/time is |year=.



For dates, these are required (all other variations emit an error message):

	|year= or

	|year= |month= or

	|year= |month= |day=

	

If time is included, these are required (all other variations emit an error message):

	|hour= or

	|hour= |minute= or

	|hour= |minute= |second=



]]



local function is_valid_date_time (year, month, day, hour, minute, second)

	if not year or (not month and day) then										-- must have YMD, YM, or Y

		return false;

	end



	year = tonumber (year);

	if not year or 1582 > year or 9999 < year then return false; end			-- must be four digits in gregorian calander

	

	if month then

		month = tonumber (month);

		if not month or 1 > month or 12 < month then return false; end			-- 1 to 12

	end

	if day then

		day = tonumber (day);

		if not day or 1 > day or get_days_in_month (year, month) < day then		-- 1 to 28, 29, 30, or 31 depending on month

			return false;

		end

	end



	if ((minute or second) and not hour) or (not minute and second) then		-- must have H:M:S or H:M or H or none at all

			return false;

	end

	

	if hour then

		hour = tonumber (hour);

		if not hour or 0 > hour or 23 < hour then return false; end				-- 0 to 23

	end

	if minute then

		minute = tonumber (minute);

		if not minute or 0 > minute or 59 < minute then return false; end		-- 0 to 59

	end

	if second then

		second = tonumber (second);

		if not second or 0 > second or 59 < second then return false; end		-- 0 to 59

	end

	

	return true;



end



--[[--------------------------< M A I N >----------------------------------------------------------------------



Supported parameters:

	date and time parameters:

		|year= (required), |month=, |day=

		|hour=, |minute=, |second=

		|utc offset=

		|duration=



	presentation parameters:

		|color=

		

	wrapping-text parameters:

		|event lead= – text ahead of countdown text while event is in progress; countdown text is time to end of event; default is static_text.ends

		|event tail= – text that follows countdown text while event is in progress; default is empty string

		|expired= - display text when event is in the past; default is static_text.passed; when |duration= is set then default is static_text.ended

		|lead= – text ahead of countdown text; default is static_text.begins; overridden by |event lead= while event is in progress;

		|tail= – text that follows countdown text; default is empty string; overridden by |event tail= while event is in progress



]]



function p.main(frame)

	local args = getArgs(frame)



	if false == is_valid_date_time (args.year, args.month, args.day, args.hour, args.minute, args.second) then	-- validate our inputs; minimal requirement is |year=

		return  static_text.invalid;

	end

																				-- convert event time parameters to seconds; use default January 1 @ 0h for defaults if not provided

	local event = os.time({year=args.year, month=args.month or 1, day=args.day or 1, hour=args.hour or 0, min=args.minute, sec=args.second});	-- convert to seconds

	if args'utc offset' then

		event = event - utc_offset(args'utc offset']);							-- adjust event time to UTC from local time

	end

	

	if 'none' == args.expired then

		args.expired = '';

	end

	

	if event < os.time () then													-- if event time is in the past

		if not args.duration then

			return args.expired or static_text.passed;							-- if the event start time has passed, we're done

		else

			event = event + duration (args.duration);							-- calculate event ending time

			if event < os.time () then

				return args.expired or static_text.ended;						-- if the event start time + duration has passed, we're done

			end

		end

	else																		-- here when event has not yet started or occured

		if not args.lead then

			if args.duration then

				args.lead = static_text.begins;									-- default lead text when |duration= set but |lead= not set

			else

				args.lead = static_text.eventtime;								-- default lead text when |duration= and |lead= not set

			end

		end

		args.duration = nil;													-- event not yet started; unset so that we render text around the countdown correctly

	end

	

	local today = os.date ('*t');												--fetch table of current date time parameters from the server

	local event_time = os.date ('*t', event);									--fetch table of event date time parameters from the server

	local hms_til_start = diff_time (event_time, today)							-- table of time difference (future time - current time)

	if hms_til_start.hour < 0 then												-- will be negative if we need to borrow hours from day

		hms_til_start.hour = hms_til_start.hour + 24;							-- borrow a day's worth of hours from event start date

		event_time.day = event_time.day - 1;

	end



	local ymd_til_start = diff_date (event_time, today)							-- table of date difference (future date - current date)



	local result = {}															-- results table with some formatting; values less than one are not added to the table 

	table.insert (result, format_unit (ymd_til_start.year, 'year'));			-- add date parameters

	table.insert (result, format_unit (ymd_til_start.month, 'month'));

	table.insert (result, format_unit (ymd_til_start.day, 'day'));

	

	local count = #result;														-- zero if less than 24 hours to event; when less than 24 hours display all non-zero time units

	table.insert (result, format_unit (hms_til_start.hour, 'hour'));			-- always include hours if it is not zero

	if args.hour or 0 == count then												-- if event start hour provided in template, show non-zero minutes

		table.insert (result, format_unit (hms_til_start.min, 'minute'));

	end

	if (args.minute and args.hour) or 0 == count then							-- if event start hour and minute provided in template, show non-zero seconds

		table.insert (result, format_unit (hms_til_start.sec, 'second'));

	end

	

	result = table.concat (result, ', ');

	result = mw.ustring.gsub(result, '(%d+)', '<span style="color: ' .. (args.color or 'blue') .. '; font-weight: bold;">%1</span>')

	local refreshLink = mw.title.getCurrentTitle():fullUrl{action = 'purge'}

	refreshLink = mw.ustring.format(' <sup>[<span class="plainlinks">[%s refresh]</span>]</sup>', refreshLink)



	if not args.duration then													-- will be nil if event hasn't started yet or |duration= not specified

		args.lead = args.lead or static_text.eventtime;							-- use default begins text

	else

		args.lead = args'event lead' or static_text.ends;						-- event has started use |event lead= text or default ends text

		args.tail = args'event tail'];											-- and use |event tail= text

	end



	if 'none' == args.lead then													-- here, if either arg.lead and args['event lead'] were set to keyword'none'

		args.lead = '';															-- set lead text to empty string

	elseif args.lead then

		args.lead = args.lead .. ' ';											-- add a space

	end



	if args.tail then

		args.tail = ' ' .. args.tail;											-- add a space

	else

		args.tail = '';															-- empty string for concatenation

	end

	

	return args.lead .. result .. args.tail .. refreshLink;

end



return p