AuthServer

local users = {}

local function loadUsers()
  local file = fs.open("users.txt", "r")
  if file then
    for line in file.readLine() do
      local username, password = line:match("([^:]+):([^:]+)")
      users[username] = password
    end
    file.close()
  else
    error("Benutzerdatei nicht gefunden.")
  end
end

local function authenticate(username, password)
  return users[username] and users[username] == password
end

local function getModemSide()
  local file = fs.open("modemSide.txt", "r")
  if file then
    local side = file.readLine()
    file.close()
    return side
  else
    return nil
  end
end

local function setModemSide(side)
  local file = fs.open("modemSide.txt", "w")
  file.writeLine(side)
  file.close()
end

local function askForModemSide()
  print("Bitte wähle die Seite des Modems: ")
  local sides = {"left", "right", "top", "bottom", "front", "back"}
  for i, side in ipairs(sides) do
    print(i .. ". " .. side)
  end
  local choice = read()
  return sides[tonumber(choice)]
end

local function startAuthServer(modemSide)
  loadUsers()

  if not rednet.isOpen(modemSide) then
    rednet.open(modemSide)
  end

  print("Auth-Server läuft auf der Seite: " .. modemSide)
  while true do
    local senderId, message, protocol = rednet.receive()
    local username, password = string.match(message, "([^:]+):([^:]+)")
    if authenticate(username, password) then
      rednet.send(senderId, "SUCCESS", protocol)
    else
      rednet.send(senderId, "FAILURE", protocol)
    end
  end
end

textutils.slowPrint("Daedalus OS")
sleep(2)

local modemSide = getModemSide()

if not modemSide then
  modemSide = askForModemSide()
  setModemSide(modemSide)
end

startAuthServer(modemSide)