-- This module implements [[Template:Infobox person/weight]]



local p = {}



local function clean_weight(s)



	s = mw.ustring.gsub(s, 'kilogram', 'kg')

	s = mw.ustring.gsub(s, 'kgs', 'kg')

	s = mw.ustring.gsub(s, 'kg[%.,]', 'kg')



	s = mw.ustring.gsub(s, 'pound', 'lb')

	s = mw.ustring.gsub(s, 'lbs', 'lb')

	s = mw.ustring.gsub(s, 'lb[%.,]', 'lb')



	s = mw.ustring.gsub(s, 'stone', 'st')

	s = mw.ustring.gsub(s, 'sts', 'st')

	s = mw.ustring.gsub(s, 'st[%.,]', 'st')



	s = mw.ustring.gsub(s, '%[%[kg%]%]s', '[[Kilogram|kg]]')



	return s

end



local function isnumber(s)

	if s then

		s = mw.ustring.gsub(s, '%+%s*%d+%s*/%s*%d+%s*$', '')

		s = mw.ustring.gsub(s, '%s*[–%-]%s*', '')

		return tonumber(s)

	end

	return nil

end



local function get_convert_weight_args(s, kg_stlb, lb_stlb)

	local prefer_m = (prefer or '') == 'm'

	local force_m = (enforce or '') == 'm'

	local prefer_cm = (prefer or '') == 'cm'

	local force_cm = (enforce or '') == 'cm'

	

	unconverted = clean_weight(s or '') -- basic unit cleaning

	

	s = mw.ustring.gsub(unconverted, '&[Nn][Bb][Ss][Pp];', ' ')

	

	local kg = mw.ustring.find(s, 'kg')

	local st = mw.ustring.find(s, 'st')

	local lb = mw.ustring.find(s, 'lb')

	

	if kg == nil and st == nil and lb == nil then

		return '', unconverted

	end

	

	if kg ~= nil and st == nil and lb == nil then

		local n = mw.ustring.sub(s, 1, kg - 1)

		if isnumber(n) then

			return {n,'kg',kg_stlb and 'lb stlb' or 'lb',0,['abbr'='on'}, mw.ustring.sub(s, kg+2)

		end

		return '', unconverted

	end

	

	if lb ~= nil and kg == nil and st == nil then

		local n = mw.ustring.sub(s, 1, lb - 1)

		if isnumber(n) then

			return {n,'lb',lb_stlb and 'kg stlb' or 'kg',0,['abbr'='on'}, mw.ustring.sub(s, lb+2)

		end

		return '', unconverted

	end

	

	if st ~= nil and kg == nil and lb == nil then

		local n = mw.ustring.sub(s, 1, st - 1)

		if isnumber(n) then

			return {n,'st','lb kg',0,['abbr'='on'}, mw.ustring.sub(s, st+2)

		end

		return '', unconverted

	end



	if lb ~= nil and st ~=nil and kg == nil then

		local n1 = mw.ustring.sub(s, 1, st - 1)

		local n2 = mw.ustring.sub(s, st+2, lb - 1)

		if isnumber(n1) and isnumber(n2) then

			return {n1,'st',n2,'lb', 'lb kg',0,['abbr'='on'}, mw.ustring.sub(s, lb+2)

		end

		return '', unconverted

	end

	

	return '', unconverted

end



function convert_weight(frame, args)

	local targs, str = get_convert_weight_args(args1], (args'kg-stlb' or '') ~= '', (args'lb-stlb' or '') ~= '')



	if type(targs) == 'table' then

		return frame:expandTemplate{ title = 'convert', args = targs} .. str

	else

		return str

	end

end



function p.weight(frame)

	return convert_weight(frame, frame.args1 and frame.args or frame:getParent().args)

end



return p