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



local p = {}



local function clean_length(s)

	s = mw.ustring.gsub(s, 'centimetre', 'cm')

	s = mw.ustring.gsub(s, 'centimeter', 'cm')

	s = mw.ustring.gsub(s, 'cms', 'cm')

	s = mw.ustring.gsub(s, 'cm%.', 'cm')

	s = mw.ustring.gsub(s, 'metre', 'm')

	s = mw.ustring.gsub(s, 'meter', 'm')

	s = mw.ustring.gsub(s, 'ms', 'm')

	s = mw.ustring.gsub(s, 'm%.', 'm')

	s = mw.ustring.gsub(s, 'inches', 'in')

	s = mw.ustring.gsub(s, 'inch', 'in')

	s = mw.ustring.gsub(s, 'ins', 'in')

	s = mw.ustring.gsub(s, 'in%.', 'in')

	s = mw.ustring.gsub(s, '%[%[[Cc]entim|cm%]%]', '[[Centimetre|cm]]')

	s = mw.ustring.gsub(s, '%[%[cm%]%]s', '[[Centimetre|cm]]')

	s = mw.ustring.gsub(s, '%[%[m%]%]s', '[[Metre|m]]')

	s = mw.ustring.gsub(s, '%[%[in|in%]%]', '[[inch|in]]')

	

	return s

end



local function isnumber(s)

	if s then

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

		return tonumber(s)

	end

	return nil

end



local function get_convert_length_args(s, prefer, enforce)

	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_length(s or '') -- basic unit cleaning

	

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

	

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

	local c = mw.ustring.find(s, 'cm')

	local i = mw.ustring.find(s, 'in')

	

	if m == nil and i == nil then

		return '', unconverted

	end

	

	if c ~= nil and i == nil then

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

		if isnumber(n) then

			return force_m

				and {n/100,'m','in',0,['abbr'='on'}

				or {n,'cm','in',0,['abbr'='on'}, mw.ustring.sub(s, c+2)

		end

		return '', unconverted

	end

	

	if m ~= nil and c == nil and i == nil then

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

		if isnumber(n) then

			return force_cm 

				and {n*100,'cm','in',0,['abbr'='on'}

				or {n,'m','in',0,['abbr'='on'}, mw.ustring.sub(s, m+1)

		end

		return '', unconverted

	end

	

	if i ~= nil and m == nil then

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

		if isnumber(n) then

			return (force_m or prefer_m)

				and {n,'in','m',2,['abbr'='on'}

				or {n,'in','cm',0,['abbr'='on'}, mw.ustring.sub(s, i+2)

		end

		return '', unconverted

	end

	

	return '', unconverted

end



function convert_length(frame, args)

	local targs, str = get_convert_length_args(args1], args'prefer' or '', args'enforce' or '')



	if type(targs) == 'table' then

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

	else

		return str

	end

end



function p.length(frame)

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

end



return p