-- This module provides some functions to prepare template parameters

-- for use with Template:Convert.

-- This module is not used by Template:Convert or Module:Convert.



local function stripToNil(text)

	-- If text is a non-empty string, return its trimmed content,

	-- otherwise return nothing (empty string or not a string).

	if type(text) == 'string' then

		return text:match('(%S.-)%s*$')

	end

end



-- Remove commas and references (any strip markers) from a number.

-- First usage in Template:Infobox_UK_place/dist (June 2018)

local function cleanNumber(frame)

	local args = frame.args

	local text = stripToNil(args1]) or ''

	if text == '' or tonumber(text) then

		return text

	end

	return mw.text.killMarkers(text):gsub(',', '')

end



local fractions = {

	'½' = '1/2',

	'⅓' = '1/3',

	'⅔' = '2/3',

	'¼' = '1/4',

	'¾' = '3/4',

	'⅛' = '1/8',

	'⅜' = '3/8',

	'⅝' = '5/8',

	'⅞' = '7/8',

}



local fractionNumbers = {

	'½' = 1/2,

	'⅓' = 1/3,

	'⅔' = 2/3,

	'¼' = 1/4,

	'¾' = 3/4,

	'⅛' = 1/8,

	'⅜' = 3/8,

	'⅝' = 5/8,

	'⅞' = 7/8,

}



-- Format regular input with fraction (MOS-confirmant) into Convert-format "12+3/8" ("+" added).

-- First usage in Template:NFL_predraft (August 2017)

local function number(frame)

	--[[ Preprocess a template parameter to translate a number to be used as

	input for {{convert}}.

	{{#invoke:convert/helper|number|12 3/8}} → 12+3/8

		Input				Output

		12					12

		12 3/8				12+3/8

		{{frac|12|3|8}}		12+3/8

		12{{frac|3|8}}		12+3/8

		12⅜					12+3/8

	Template:Fraction redirects to Template:Frac so either may be used in the input.

	]]

	local args = frame.args

	local text = stripToNil(args1]) or ''

	if text == '' or tonumber(text) then

		return text  -- examples: '', '12', '12.3', '12.3e4', or negative

	end

	text = text:gsub(' ', ' '):gsub('  +', ' '):gsub(' *%+ *', '+'):gsub('⁄', '/'):gsub('⁄', '/')

	local integer, numerator, denominator, rest

	-- Look for a fraction of form '12 3/8' or '12+3/8' or '3/8'.

	integer, numerator, denominator = text:match('^(%d+)[ +](%d+)/(%d+)$')

	if integer then

		return integer .. '+' .. numerator .. '/' .. denominator

	end

	numerator, denominator = text:match('^(%d+)/(%d+)$')

	if numerator then

		return numerator .. '/' .. denominator

	end

	-- Look for an expanded fraction such as the result of {{frac|12|3|8}} or 12{{frac|3|8}} or {{frac|3|8}}.

	numerator, denominator = text:match('<sup>(%d+)</sup>/<sub>(%d+)</sub></span>')

	if numerator then

		integer = text:match('(%d+)<span class="sr-only">') or

			text:match('^(%d+)%s*&#x200B;<span') or  -- Template:Frac outputs zwsp since December 2017

			text:match('^(%d+)%s*<span')

		return (integer and (integer .. '+') or '') .. numerator .. '/' .. denominator

	end

	-- Look for a fraction of form '12¾' or '¾'.

	integer, rest = text:match('^(%d*)%s*(.*)')

	local expand = fractionsrest

	if expand then

		return (integer == '' and integer or (integer .. '+')) .. expand

	end

	return text

end



local function distanceNumber(text)

	-- Return a number corresponding to text (0 if text is empty) or throw an error if invalid.

	text = text or 0

	if tonumber(text) then

		return tonumber(text)

	end

	-- Look for a fraction of form '12¾' or '¾'.

	local integer, expand = text:match('^(%d*)%s*(.*)')

	if integer == '' then

		integer = 0

	else

		integer = tonumber(integer)

	end

	if expand == '' then

		expand = 0

	else

		expand = fractionNumbersexpand

	end

	if integer and expand then

		return integer + expand

	end

	error('Invalid number "' .. text .. '"', 0)

end



-- First usage in Template:Horse_race_distance (January 2024)

local function horseRaceDistance(frame)

	local args = frame:getParent().args

	local miles = stripToNil(args1])

	local furlongs = stripToNil(args2])

	local yards = stripToNil(args3])

	local show = {}

	if miles then

		table.insert(show, miles .. 'm')

	end

	if furlongs then

		table.insert(show, furlongs .. 'f')

	end

	if yards then

		table.insert(show, yards .. 'y')

	end

	miles = distanceNumber(miles)

	furlongs = distanceNumber(furlongs)

	yards = distanceNumber(yards)

	local meters = miles * 1609.344 + furlongs * 201.168 + yards * 0.9144

	return

		'<span data-sort-value="' ..

		tostring(meters) ..

		'&nbsp;!">' ..

		table.concat(show, ' ') ..

		'</span>'

end



return {

	number = number,

	cleanNumber = cleanNumber,

	horseRaceDistance = horseRaceDistance,

}