-- This module powers {{countdown}}.



local p = {}



-- Constants

local lang = mw.language.getContentLanguage()

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



local function formatMessage(secondsLeft, event, color)

	local timeLeft = lang:formatDuration(secondsLeft, {'years', 'weeks', 'days', 'hours', 'minutes', 'seconds'})

	-- Find whether we are plural or not.

	local isOrAre

	if string.match(timeLeft, '^%d+') == '1' then

		isOrAre = 'is'

	else

		isOrAre = 'are'

	end

	-- Color and bold the numbers, because it makes them look important.

	timeLeft = string.gsub(timeLeft, '(%d+)', '<span style="color: ' .. (color or '#F00') .. '; font-weight: bold;">%1</span>')

	return string.format('There %s %s until %s.', isOrAre, timeLeft, event)

end



function p.main(frame)

	local args = getArgs(frame)



	if not (args.year and args.month and args.day) then

		return '<strong class="error">Error: year, month, and day must be specified</strong>'

	end



	local timeArgs = {year=args.year, month=args.month, day=args.day, hour=args.hour, min=args.minute, sec=args.second}

	for k,v in pairs(timeArgs) do

		if not tonumber(v) then

			error('Argument ' .. k .. ' could not be parsed as a number: ' .. v)

		end

	end

	local eventTime = os.time(timeArgs)

	local timeToStart = os.difftime(eventTime, os.time()) -- (future time - current time)

	local text

	if timeToStart > 0 then

		-- Event has not begun yet

		text = formatMessage(timeToStart, args.event or 'the event begins', args.color)

	elseif args.duration then

		local timeToEnd

		if args'duration unit' then

			-- Duration is in unit other than seconds, use formatDate to add

			timeToEnd = tonumber(lang:formatDate('U', '@' .. tostring(timeToStart) .. ' +' .. tostring(args.duration) .. ' ' .. args'duration unit']))

		else

			timeToEnd = timeToStart + (tonumber(args.duration) or error('args.duration should be a number of seconds', 0))

		end

		if timeToEnd > 0 then

			-- Event is in progress

			text = args.eventstart or formatMessage(timeToEnd, (args.event or 'the event') .. ' ends', args.color)

		else

			-- Event had a duration and has now ended

			text = args.eventend or ((lang:ucfirst(args.event or 'The event')) .. ' has ended.')

		end

	else

		-- Event had no duration and has begun

		text = args.eventstart or ((lang:ucfirst(args.event or 'The event')) .. ' has started.')

	end

	local refreshLink

	if args.refresh == 'no' then

		refreshLink = ''

	else

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

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

	end

	return text .. refreshLink

end



return p