local p = {}



local concat = table.concat

local insert = table.insert

local format = mw.ustring.format

local frame = mw.getCurrentFrame()



function p._length(num, args)

	local km = args"length_km" .. num or ''

    local mi = args"length_mi" .. num or ''

    local nmi = args"length_nmi" .. num or ''

    local ref = args"length_ref" .. num or ''

    local notes = args"length_notes" .. num or ''



	if mi == '' and km == '' and nmi == '' then

	    return nil																-- none of these set, abandon

	end



    local first, unit, unit2, unit3

--    if nmi ~= '0' and mi == '' and km == '' then

	if tonumber (nmi) then

		first = nmi

		unit = "nmi"

		unit2 = "km mi"

		unit3 = "km mi"

--    elseif mi ~= '0' and km == '' then

	elseif tonumber (mi) then

		first = mi

		unit = "mi"

		unit2 = "km"

		unit3 = "m"

--    elseif km ~= '0' and mi == '' then

	elseif tonumber (km) then

		first = km

		unit = "km"

		unit2 = "mi"

		unit3 = "mi ft"

	else

		return nil																-- something other than numbers so abandon

    end



	if not first then

		return nil

	end

--    if mi == '' and km == '' and nmi == '' then

--        return nil

--    elseif notes ~= '' and first < '1' then

	if notes ~= '' and first < '1' then

    	return frame:expandTemplate{ title = 'cvt', args = { first, unit, unit3, disp = "x", ref .. "&nbsp;("}} .. ")<div>" .. notes .. "</div>"

    elseif notes == '' and first < '1' then

    	return frame:expandTemplate{ title = 'cvt', args = { first, unit, unit3, disp = "x", ref .. "&nbsp;("}} .. ")"

    elseif notes ~= '' then

		return frame:expandTemplate{ title = 'cvt', args = { first, unit, unit2, disp = "x", ref .. "&nbsp;("}} .. ")<div>" .. notes .. "</div>"

	else

    	return frame:expandTemplate{ title = 'cvt', args = { first, unit, unit2, disp = "x", ref .. "&nbsp;("}} .. ")"

    end

end

    



function p.length(frame)

    local pframe = frame:getParent()

    local config = frame.args -- the arguments passed BY the template, in the wikitext of the template itself

    local args = pframe.args -- the arguments passed TO the template, in the wikitext that transcludes the template

    

    local num = config.num or ''

    return p._length(num, args)

end



return p