--

-- This module implements [[Template:Percentage]]

--

local p = {}



local math_module = require( "Module:Math" )

local precision = math_module._precision

local sortkey = require( "Module:Sortkey" )



local function rnd(num, digits)

	-- This function implements {{rnd}}

	return math_module._precision_format(tostring(num), digits)

end



local function oom(num)

	-- This function implements {{order of magnitude}}

	return math_module._order(tostring(num))

end



function _nonscinote(num)

	-- This function undoes scientific notation

	if mw.ustring.match(num or '', '^%s*(%d)%.(%d+)<span[^<>]*>×</span>10<sup>([%-−]*)(%d)</sup>%s*$') then

		local a,b,c,d = mw.ustring.match(num or '', '^%s*(%d)%.(%d+)<span[^<>]*>×</span>10<sup>([%-−]*)(%d)</sup>%s*$')

		d = tonumber(d) or 1

		if c ~= '' then

			return '0.' .. mw.ustring.rep('0', d - 1) .. a .. b

		else

			return a .. mw.ustring.sub(b .. mw.ustring.rep('0', d ), 1, d)

		end

	end

	return num

end



local function fmtout(num,snote)

	if snote then

		return _nonscinote(num)

	else

		return num

	end

end



function _percentage(n1, n2, prec, suffix, pad, sigfig, sn)

	local pct = 100*n1/n2

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

			.. sortkey._sortKeyForNumber(pct) .. '♠" style="display:none"></span>'



	-- prec = math.floor(prec)



	if sigfig ~= '' then

		if pct ~= 0 then

			return skey .. fmtout(rnd(pct, tonumber(sigfig) - oom(pct) - 1), sn) .. suffix

		else

			return skey .. fmtout(rnd(pct, tonumber(sigfig) - 3), sn) .. suffix

		end

	end

	if pad ~= '' then

		return skey .. fmtout(rnd(pct, prec), sn) .. suffix

	end

	

	prec = (prec < 0) and 0 or prec

	if pct ~= 0 then

		pct = ((pct < 0) and -1 or 1)*math.floor(math.abs(pct * 10^prec) + 0.5) / 10^prec

	end

	

	return skey .. fmtout(pct, sn) .. suffix

end



function p.main(frame)

	local args = frame.args1 and frame.args or frame:getParent().args

	local yesno = require('Module:Yesno')

	return _percentage(

		tonumber(args1]) or 0,

		tonumber(args2]) or 100,

		tonumber(args3]) or tonumber(args'pad']) or 0,

		args'%' or '%', args'pad' or '',

		args'sigfig' or '',

		yesno(args'nonscinote' or 'no')

		)

end



return p