-- Migrate Encryption
-- Decrypt Autorun
local pass

-- Turns off debug so people can't steel mi password
_G.debug = nil

-- Encryption API
-- Nathan's Basic Encryption Library
-- Encryption API
-- Nathan's Basic Encryption Library
local function encrypt(str, password, iter)
  iter = iter or 0

  -- Make Seed
  local seed = 0
  local seedtable = {string.byte(password, 1, -1)}
  math.randomseed(string.byte(password, -1) * string.byte(password, 1))

  for k,v in pairs(seedtable) do
    math.random() math.random()
    local operation = math.random(4)
    if operation == 1 then
      seed = seed + v
    elseif operation == 2 then
      seed = seed - v
    elseif operation == 3 then
      seed = seed * v
    elseif operation == 4 then
      seed = seed / v
    end
    seed = math.ceil(seed)
  end

  -- Start Encryption Process
  math.randomseed(seed)

  for i=1,iter do
    math.random()
  end

  local cipher = ""
  for i=1,#str do
    if string.byte(str, i) == 10 then
      cipher = cipher..str:sub(i,i)
    else
      local randseed = seedtable[math.random(#seedtable)]

      while string.byte(str, i)+randseed == 10 or string.byte(str, i)-randseed == 10 do
        randseed = seedtable[math.random(#seedtable)]
      end

      if string.byte(str, i)+randseed > 255 then
        randseed = -randseed
      end
        cipher = cipher..string.char(string.byte(str, i)+randseed)
    end
  end

  return cipher
end

local function decrypt(cipher, password, iter)
  iter = iter or 0

    -- Check for args
  if cipher == nil then
    return nil
  end

  -- Make Seed
  local seed = 0
  local seedtable = {string.byte(password, 1, -1)}
  math.randomseed(string.byte(password, -1) * string.byte(password, 1))

  for k,v in pairs(seedtable) do
    math.random() math.random()
    local operation = math.random(4)
    if operation == 1 then
      seed = seed + v
    elseif operation == 2 then
      seed = seed - v
    elseif operation == 3 then
      seed = seed * v
    elseif operation == 4 then
      seed = seed / v
    end
    seed = math.ceil(seed)
  end

  -- Start Encryption Process
  math.randomseed(seed)

  for i=1,iter do
    math.random()
  end

  local str = ""
  for i=1,#cipher do
    if string.byte(cipher, i) == 10 then
      str = str..cipher:sub(i,i)
    else
      local randseed = seedtable[math.random(#seedtable)]

      while string.byte(cipher, i)+randseed == 10 or string.byte(cipher, i)-randseed == 10 do
        randseed = seedtable[math.random(#seedtable)]
      end

      if string.byte(cipher, i)-randseed < 0 then
        randseed = -randseed
      end
        str = str..string.char(string.byte(cipher, i)-randseed)
    end
  end

  return str
end

print("Testing Encryption System")
local success, returned = pcall(function() return decrypt(encrypt("hellowurld",string.char(128)..string.char(0)), string.char(128)..string.char(0)) end)
if not success or returned ~= "hellowurld" then error("Test Failed: "..returned) else print("Success!") end

print("Enter key: ")
pass = read("*")

print("Rewriting fs API...")

-- Set up encryption
local oldfsopen = fs.open
local thisname = shell.getRunningProgram()

_G.fs.open = function(dir, mode)

  if dir and (dir:sub(1,5) == "/rom/" or dir:sub(1,4) == "rom/" or dir:sub(1,4) == "disk" or dir:sub(1,5) == "/disk" or thisname == dir) then
    return oldfsopen(dir, mode)
  end

  local fopen = oldfsopen(dir, mode)
  if not fopen then return nil end

  local charIter = 0

  local returntable = {}

    returntable["readLine"] = function()
      local results = fopen.readLine()
      local dresult =  decrypt(results, pass, charIter)
      if dresult then
        charIter = charIter+#dresult+1
      end
      return dresult
    end

    returntable.readAll = function()
      local results
      local dresult = ""
      repeat
        results = fopen.readLine()
        local rawresult = decrypt(results, pass, charIter)
        if rawresult then
          charIter = charIter+#rawresult+1
          dresult = dresult..rawresult.."\n"
        end
      until not results

      return dresult
    end

    returntable["write"] = function(data)
        -- Detect bunary mode
      if type(data) == "number" then
        data = string.char(data)
      end
      local dresult =  fopen.write(encrypt(data, pass, charIter))
      if data then
        charIter = charIter+#data
      end
      return dresult
    end

    returntable["writeLine"] = function(data)
      local dresult =  fopen.writeLine(encrypt(data, pass, charIter))
      if data then
        charIter = charIter+#data+1
      end
      return dresult
    end

    returntable["flush"] = fopen.flush

    returntable["read"] = function()
      local dresult =  string.byte(decrypt(string.char(fopen.read()), pass, charIter))
      charIter = charIter+1
      return dresult
    end

  -- Essential Functions
  returntable["close"] = fopen.close

  return returntable
end

print("Done!")

print("Migrating files in root...")

function scanAllFiles(dir, r)
  local files = {}
  for _,v in pairs(fs.list(dir)) do
    if fs.isDir(v) then
      if v:sub(1,3) ~= "rom" and v:sub(1,7) ~= "startup" and r then
        local subfiles = scanAllFiles(v,r)
        for _,v1 in pairs(subfiles) do
          table.insert(files,v.."/"..v1)
        end
      end
    else
      table.insert(files, v)
    end
  end
  return files
end

local files = scanAllFiles("", true)
for _,v in pairs(files) do
  local f = oldfsopen(v, "r")
  local migrate = encrypt(f.readAll(), pass)
  f.close()

  local f1 = oldfsopen(v, "w")
  f1.write(migrate)
  f1.close()
end