-- Studwright Format: the number and time text every simulator, tycoon and obby needs.
--   Format.abbreviate(1530000)      --> "1.53M"
--   Format.commas(1234567)          --> "1,234,567"
--   Format.clock(3725)              --> "1:02:05"
--   Format.duration(3725)           --> "1h 2m"
--   Format.ordinal(22)              --> "22nd"
--   Format.percent(0.0125)          --> "1.25%"
-- (c) 2026 CyberMax. Studwright Licence (see LICENSE.txt).

local Format = {}

-- Suffixes up to 10^63. Override with Format.setSuffixes({...}) if your game uses other names.
local SUFFIXES = { "", "K", "M", "B", "T", "Qd", "Qn", "Sx", "Sp", "Oc", "No", "Dc", "Ud", "Dd", "Td", "Qtd", "Qnd", "Sxd", "Spd", "Ocd", "Nod", "Vg" }

function Format.setSuffixes(list: { string })
	assert(list[1] == "", "the first suffix must be an empty string")
	SUFFIXES = list
end

local function trimZeros(s: string): string
	if string.find(s, "%.") then
		s = (string.gsub(s, "0+$", ""))
		s = (string.gsub(s, "%.$", ""))
	end
	return s
end

-- abbreviate(n, decimals?) keeps up to `decimals` (default 2) digits after the point and never rounds
-- up into a wrong suffix: 999,999 shows "999.99K", not "1000K".
function Format.abbreviate(n: number, decimals: number?): string
	if n ~= n then
		return "NaN"
	end
	if n == math.huge then
		return "inf"
	elseif n == -math.huge then
		return "-inf"
	end
	local d = decimals or 2
	local sign = n < 0 and "-" or ""
	n = math.abs(n)
	if n < 1000 then
		local f = 10 ^ d
		return sign .. trimZeros(string.format("%." .. d .. "f", math.floor(n * f + 1e-9) / f))
	end
	local tier = math.min(math.floor(math.log10(n) / 3), #SUFFIXES - 1)
	local scaled = n / 10 ^ (tier * 3)
	if scaled >= 1000 and tier < #SUFFIXES - 1 then
		tier += 1
		scaled /= 1000
	end
	local f = 10 ^ d
	scaled = math.floor(scaled * f + 1e-9) / f
	return sign .. trimZeros(string.format("%." .. d .. "f", scaled)) .. SUFFIXES[tier + 1]
end

function Format.commas(n: number): string
	local sign = n < 0 and "-" or ""
	local whole = tostring(math.floor(math.abs(n)))
	local grouped = (string.gsub(string.reverse(whole), "(%d%d%d)", "%1,"))
	local out = string.reverse(grouped)
	if string.sub(out, 1, 1) == "," then
		out = string.sub(out, 2)
	end
	return sign .. out
end

-- clock(seconds) -> "m:ss" under an hour, "h:mm:ss" above.
function Format.clock(seconds: number): string
	seconds = math.max(0, math.floor(seconds))
	local h = seconds // 3600
	local m = (seconds % 3600) // 60
	local s = seconds % 60
	if h > 0 then
		return string.format("%d:%02d:%02d", h, m, s)
	end
	return string.format("%d:%02d", m, s)
end

-- duration(seconds) -> the two largest units: "2d 4h", "1h 2m", "45s".
function Format.duration(seconds: number): string
	seconds = math.max(0, math.floor(seconds))
	local units = { { 86400, "d" }, { 3600, "h" }, { 60, "m" }, { 1, "s" } }
	local parts = {}
	for _, u in units do
		if seconds >= u[1] then
			local v = seconds // u[1]
			seconds -= v * u[1]
			table.insert(parts, v .. u[2])
			if #parts == 2 then
				break
			end
		elseif #parts > 0 then
			break
		end
	end
	return #parts > 0 and table.concat(parts, " ") or "0s"
end

function Format.ordinal(n: number): string
	local last2 = n % 100
	local last = n % 10
	local suffix = "th"
	if last2 < 11 or last2 > 13 then
		if last == 1 then
			suffix = "st"
		elseif last == 2 then
			suffix = "nd"
		elseif last == 3 then
			suffix = "rd"
		end
	end
	return n .. suffix
end

function Format.percent(fraction: number, decimals: number?): string
	return trimZeros(string.format("%." .. (decimals or 2) .. "f", fraction * 100)) .. "%"
end

return Format