registerUser

local crypt = peripheral.wrap('left')
local rfidw = peripheral.wrap('right')
local rfidr = peripheral.wrap('top')
local mag = peripheral.wrap('bottom')
local tArgs = {...}
local state = {
  magCard = false,
  rfidChip = false
}

local uName,
      uPass,
      uCipher,
      uKey,
      tEvent,
      tEvArg1,
      tEvArg2

function readPass()
  local result = ''
  local x, y = term.getCursorPos()
  local e, k

  term.setCursorBlink(true)
  repeat
    e, k = os.pullEvent('key')
    if k > 1 and k < 12 and #result < 11 then
      k = ((k == 11 and 0) or k - 1)
      result = result..k
    elseif k == keys.backspace then
      result = result:sub(1, #result - 1)
    end

    term.clearLine()
    term.setCursorPos(1,y)
    for i=1, #result do
      term.write('*')
    end
  until k == keys.enter
  term.setCursorPos(1,y+1)
  term.setCursorBlink(false)

  return result
end

term.clear()
term.setCursorPos(1,1)
print('Please insert a username:')
uName = read()

local tPass
local confirmed = false

repeat
  term.clear()
  term.setCursorPos(1,1)
  print('Please insert a numeric password:')
  print('11 digits max')
  tPass = readPass()
  if #tPass > 0 then
    print('Please confirm the password:')
    uPass = readPass()
    if tPass == uPass then
      print('Password confirmed')
      confirmed = true
    else
      print('Password did not match')
    end
  else
    print('Password is required')
  end
  sleep(2)
  term.clear()
  term.setCursorPos(1,1)
until confirmed

rfidr.scan()
while rfidr.isScanning() do
  tEvent, tEvArg1 = os.pullEvent()
  if tEvent == 'rfid_detected' then
    local uKeyEnc = tEvArg1
    print('Found existing encryption key')
    print('Use existing key?')
    print('enter: confirm')
    print('backspace: generate new')
    repeat
      tEvent, tEvArg1 = os.pullEvent('key')
      if tEvArg1 == keys.enter then
        uKey = crypt.decodeKey('aes', uKeyEnc)
        state.rfidChip = true
        break
      end
    until tEvArg1 == keys.backspace
    break
  end
end

term.clear()
term.setCursorPos(1,1)
if not uKey then
  print('Generating key...')
  uKey = crypt.generateSymmetricKey('aes', 256)
  sleep(2)
end

print('Encrypting password...')
uCipher = uKey.encrypt('aes', uPass)

while not state.magCard do
  mag.beginWrite(uCipher, uName)
  mag.setInsertCardLight(true)
  print('Please swipe a mag card')
  tEvent, tEvArg1, tEvArg2 = os.pullEvent('mag_write_done')
  if #tEvArg2 > 0 then
    local magData = tEvArg2

    print('Data found on card:')
    print('enter: continue')
    print('r: restore')
    print('b: backup to local filesystem')

    while true do
      tEvent, tEvArg1 = os.pullEvent('key_up')

      if tEvArg1 == keys.enter then
        state.magCard = true
        break
      elseif tEvArg1 == keys.r then
        print('Lable cannot be restored,')
        print('please provide manually')
        mag.beginWrite(magData, read())
        print('Please swipe the card')
        os.pullEvent('mag_write_done')
        break
      elseif tEvArg1 == keys.b then
        if not fs.exists('backups') then
          fs.makeDir('backups')
        end

        local n = 1
        while fs.exists('backups/'..uName..n) do
          n = n + 1
        end
        print('Backing up to \'backups/'..uName..n..'\'')
        local backup = fs.open('backups/'..uName..n, 'w')
        backup.write(magData)
        backup.close()
        state.magCard = true
        break
      end
    end
  else
    state.magCard = true
  end

  mag.setInsertCardLight(false)
end

while not state.rfidChip do
  while not rfidw.isPresent() do
    print('Please insert a blank rfid chip into the writer')
    print('and press \'enter\' to continue')
    repeat
      tEvent, tEvArg1 = os.pullEvent('key_up')
    until tEvArg1 == keys.enter
  end

  if rfidw.isCoded() then
    print('The inserted rfid chip is already coded')
    print('replace it and press \'enter\' to continue')
    repeat
      tEvent, tEvArg1 = os.pullEvent('key_up')
    until tEvArg1 == keys.enter
  else
    print('Writing decryption key to rfid chip...')
    rfidw.encode(uKey.encode(), uName)
    local progress = rfidw.getProgress()
    local x, y
    while progress >= 0 do
      x, y = term.getCursorPos()
      term.clearLine()
      term.setCursorPos(1,y)
      term.write('Progress: '..math.floor((progress*100)+0.5)..'%')
      progress = rfidw.getProgress()
      sleep(1)
    end

    state.rfidChip = true
  end
end

term.clear()
term.setCursorPos(1,1)
print('complete')