Scramble the object placement in an osu map

scramble.lua

--X: 0-512
--Y: 0-384

-- Type bits: (-)(-)(-)(-) (spinner)(NC)(slider)(circle)

-- Circle: x,y,time,type,hitSound,extras

-- Slider: x,y,time,type,hitSound,sliderType|curvePoints,repeat,pixelLength,edgeHitsounds,edgeAdditions,extras
--         type = Linear Perfect Bezier Catmul

-- Get target file
local target = arg[1]
if not arg[1] then
    error("No file")
end

-- Open file
--target = "C:\\Users\\stravant\\AppData\\Local\\osu!\\Songs\\"..target
local f = io.open(target)
if not f then
    error("Could not find file")
end

-- Get lines
local lines = {}
local objectStart = nil
for line in f:lines() do
    table.insert(lines, line)
    if line == '[HitObjects]' then
        objectStart = #lines + 1
    elseif line:sub(1,7) == 'Version' then
        lines[#lines] = 'Version:Randomized'
    elseif line:sub(1,9) == 'BeatmapID' then
        lines[#lines] = 'BeatmapID:0'
    end
end

-- Object lines
local objects = {}
local sliders = {
    L = true;
    P = true;
    B = true;
}
for i = objectStart, #lines do
    local line = lines[i]
    local x, y, time, type, snd, extras = line:gmatch("(%d+),(%d+),([^,]+),([^,]+),([^,]+),(.*)")()
    --print("type:", type)
    if sliders[extras:sub(1,1)] then
        local curveType, curvePoints, rest = extras:gmatch("([LPB])([^,]+)(.*)")()
        local curve = {}
        for x, y in curvePoints:gmatch("|([%-%d]+):([%-%d]+)") do
            print(x, y)
            table.insert(curve, {x = tonumber(x); y = tonumber(y);})
        end
        table.insert(objects, {
            curve = curve;
            at = {x = tonumber(x); y = tonumber(y)};
            size = {
                x = math.abs(curve[#curve].x - tonumber(x)); 
                y = math.abs(curve[#curve].y - tonumber(y));
            };
            format = function(self)
                local newPoints = ""
                for _, point in pairs(self.curve) do
                    newPoints = newPoints.."|"..point.x..":"..point.y
                end
                return self.at.x..","..self.at.y..","..time..","..type..","..snd..","..
                    curveType..newPoints..rest
            end;
            move = function(self, x, y)
                local dx = x - self.at.x
                local dy = y - self.at.y
                self.at.x = x
                self.at.y = y
                for _, p in pairs(self.curve) do
                    p.x = p.x + dx
                    p.y = p.y + dy
                end
            end;
        })
    else
        print(x..','..y)
        table.insert(objects, {
            at = {x = tonumber(x); y = tonumber(y)};
            size = {x = 0; y = 0};
            format = function(self)
                return self.at.x..","..self.at.y..","..time..","..type..","..snd..","..extras
            end;
            move = function(self, x, y)
                self.at.x = x
                self.at.y = y
            end;
        })
    end
end

-- Modify objects
local width = 512
local height = 384
for _, object in pairs(objects) do
    local widthleft = width - object.size.x
    local heightleft = height - object.size.y
    object:move(math.random(1, widthleft), math.random(1, heightleft))
end

-- Rewrite
local newContent = ""
for i = 1, objectStart-1 do
    newContent = newContent..lines[i].."\n"
end
for _, object in pairs(objects) do
    newContent = newContent..object:format().."\n"
end

local newFile = target:sub(1,-4).."_jumpy.osu"

local newFile = io.open(newFile, "w")
newFile:write(newContent)
newFile:close()