#!/usr/bin/env lua
-- (C) 2022 Flecken-chan
-- Dis progwam comes with ABSOLUTELY NO WAWWANTY
-- Dis iz fwee software, and your'e welcome to redistwibute it under certain conditions

local u = {
	"u", "ü", "ǘ", "ú", "ù", "ǜ", "o", "ö", "ø", "ó", "ò", "ð",
	"U", "Ü", "Ǘ", "Ú", "Ù", "Ǜ", "O", "Ö", "Ø", "Ó", "Ò", 
}

local w = {
	"w", "W",
}

local words = {"nya", "rawr", "ara", "awoo"}

math.randomseed(69420)

function string:randomcase()
	local s = ""

	for i = 1, #self do
		local c = self:sub(i, i)

		if math.random() < 0.5 then
			c = c:upper()
		end

		s = s .. c
	end

	return s
end

local encode = {}
local decode = {}

for i = 0, 255 do
	local c

	repeat
		if math.random() < 0.5 then
			c =
				u[math.random(#u)] ..
				w[math.random(#w)] ..
				u[math.random(#u)]
		else
			c = words[math.random(#words)]:randomcase()
		end

		if math.random() < 0.5 then
			c = c .. "~"
		end
	until not decode[c]

	encode[i] = c
	decode[c] = i
end

if arg[1] == "encode" then
	local buf
	local num = 0

	while true do
		local c = io.read(1)

		if buf and c ~= buf then
			local e = encode[buf:byte(1)] .. " "
		
			if num == 1 then
				io.write(e)
			else
				io.write("" .. num .. "x " .. e)
			end

			num = 1
		else
			num = num + 1
		end

		buf = c

		if not c then
			break
		end
	end
elseif arg[1] == "decode" then
	local buf = ""
	local num = 1

	while true do
		local c = io.read(1)

		if not c then
			break
		end

		if c == " " then
			local n = buf:sub(-1) == "x" and tonumber(buf:sub(1, -2))

			if n then
				num = n
			else
				if not decode[buf] then
					error("decode error")
				end
			
				local d = string.char(decode[buf])

				for i = 1, num do
					io.write(d)
				end

				num = 1
			end

			buf = ""
		else
			buf = buf .. c
		end
	end

	if buf ~= "" then
		error("trailing data")
	end
else
	print("Usage: " .. arg[0] .. " encode|decode")
	os.exit(1)
end