pullEvent = os.pullEvent
os.pullEvent = os.pullEventRaw
users = {"mailserver"}
passwords = {"legomail"}
term.clear()
term.setCursorPos(1,1)
print("Legoman technologies authentication server running")
id = os.computerID()
term.setCursorPos(1,2)
print("Computer ID = "..id)

local firstCycle = true
local modemSide = "right"
local valid = false
local DNSID = 2

while true do
  if firstCycle then
    rednet.open(modemSide)
    firstCycle = false
  end
  event, p1, p2, p3 = os.pullEvent()
  term.clear()
  term.setCursorPos(1,1)
  print("Legoman technologies authentication server running")
  id = os.computerID()
  term.setCursorPos(1,2)
  print("Computer ID = "..id)

  if event =="char" then
    if p1 == "m" then
      for i, v in ipairs(users) do
        print(v)
      end
    end
    if p1 == "a" then
      term.setCursorPos(1,10)
      print("Enter name: ")
      name = read()
      print("Enter password: ")
      password = read()
      print("Confim add " .. name .. " Y/N?")
      if read() == "Y" then
        table.insert(users, name)
        table.insert(passwords, password)
        print("Added")
      end
    end
    if p1 == "r" then
      print("Enter name: ")
      name = read()
      print("Confim remove " .. name .. " Y/N?")
      if read() == "Y" then
        for i,v in ipairs(users) do
          if name == v then
            table.remove(users, i)
            table.remove(passwords, i)
          end
        end
      end
    end
  end

  if event == "terminate" then
    term.setCursorPos(1,10)
    print("Enter password: ")
    if read("*") == "unlock" then
      os.pullEvent = pullEvent
      shell.exit()
    end
  end

  if event == "rednet_message" then
    senderId = p1
    message = p2
    term.setCursorPos(1,4)
    term.clearLine()
    print(message)
    for i,v in ipairs(users) do
      if message == v then
      valid = true
      password = passwords[i]
      user = users[i]
      break
      else
      valid = false
      end
    end

    if valid then
    rednet.send(senderId, "Valid")
    print("Valid")
    else
    rednet.send(senderId, "Not Valid")
    print("Not valid")
    end
    sender, passwordRcv, dist = rednet.receive(3)
    print(sender)
    if passwordRcv == password then
      rednet.send(senderId, "Authenticated")
      rednet.send(DNSID, "Add " .. senderId .. " " .. user)
      print("Authenticated")
    else
      rednet.send(senderId, "Failed")
    end
  end
end