local p = {}



local digits = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'



local function normalizeFullWidthChars(s)

	return mw.ustring.gsub(s, '[！-～]', function(s)

		return mw.ustring.char(mw.ustring.codepoint(s, 1) - 0xFEE0)

	end)

end



local function _convert(n, base, from, precision, width, default, prefix, suffix)

	n = tostring(n)



	-- strip off any leading '0x' (unless x is a valid digit in the input base)

	from = tonumber(from)

	if not from or from < 34 then

		local c

		n, c = n:gsub('^(-?)0[Xx]', '%1')

		if c > 0 and not from then from = 16 end

	end



	-- check for a negative sign. Do this while the input is still in string form,

	-- because tonumber doesn't support negative numbers in non-10 bases.

	local sign = ''

	local c

	n, c = n:gsub('^-', '')

	if c > 0 then sign = '-' end



	-- replace any full-width Unicode characters in the string with their ASCII equivalents

	n = normalizeFullWidthChars(n)



	-- handle scientific notation with whitespace around the 'e' e.g. '5 e7'

	n = n:gsub('%s*[eE]%s*', 'e')



	from = from or 10

	local num = tonumber(n, from)

	base = tonumber(base)

	precision = tonumber(precision)

	width = tonumber(width)



	if not num or not base then return default or n end



	local i, f = math.modf(num)



	local t = {}

	repeat

		local d = (i % base) + 1

		i = math.floor(i / base)

		table.insert(t, 1, digits:sub(d, d))

	until i == 0

	while #t < (width or 0) do

		table.insert(t, 1, '0')

	end

	local intPart = table.concat(t, '')



	-- compute the fractional part

	local tf = {}

	while f > 0 and #tf < (precision or 10) do

		f = f * base

		i, f = math.modf(f)

		table.insert(tf, digits:sub(i + 1, i + 1))

	end



	-- add trailing zeros if needed

	if precision and #tf < precision then

		for i = 1, precision - #tf do

			table.insert(tf, '0')

		end

	end



	local fracPart = table.concat(tf, '')



	-- remove trailing zeros if not needed

	if not precision then

		fracPart = fracPart:gsub('0*$', '')

	end



	-- add the radix point if needed

	if #fracPart > 0 then

		fracPart = '.' .. fracPart

	end



	return (prefix or '') .. sign .. intPart .. fracPart .. (suffix or '')

end



function p.convert(frame)

	-- Allow for invocation via #invoke or directly from another module

	local args

	if frame == mw.getCurrentFrame() then

		args = frame.args

	else

		args = frame

	end



	local n = args.n

	local base = args.base

	local from = args.from

	local precision = args.precision

	local width = args.width

	local default = args.default

	local prefix = args.prefix

	local suffix = args.suffix

	return _convert(n, base, from, precision, width, default, prefix, suffix)

end



setmetatable(p, {

	__index = function(t, k)

		local from, base = k:match('^([0-9]+)to([0-9]+)$')

		if not from then return nil end

		return function(frame)

			local args = frame.args

			return _convert(mw.text.trim(args1]), base, from, args.precision, args.width,

				args.default, args.prefix, args.suffix)

		end

	end

})



return p