aUser = {}
aPass = {}
nUserList = 0


local function inputBox(len, x, y, mask)
  local bInput = true
  local sOutput = ""
  term.setCursorPos(x,y)
  while bInput == true do
    local sEvent, param = os.pullEvent()
    if sEvent == "key" then
      if param == 28 then
        if string.len(sOutput) > 0 then
          bInput = false
        end
      elseif param == 14 then
        sOutput = string.sub(sOutput,1,string.len(sOutput)-1)
        term.setCursorPos(x+string.len(sOutput),y)
        io.write(" ")
        term.setCursorPos(x+string.len(sOutput),y)
      end
    end
    if sEvent == "char" then
      if string.len(sOutput) < len then
        sOutput = sOutput .. param
        term.setCursorPos(x,y)
        if not mask then
          io.write(sOutput)
        else
          for n=1,string.len(sOutput) do
            io.write("*")
          end
        end
      end
    end
  end
  return sOutput
end

local function drawBox(x, y, w, h)
  for n=0,h-1 do
    term.setCursorPos(x,y+n)
    if n == 0 then
      io.write("+")
      for n2=1,w-2 do
        io.write("-")
      end
      io.write("+")
    elseif n == h-1 then
      io.write("+")
      for n2=1,w-2 do
        io.write("-")
      end
      io.write("+")
    else
      io.write("|")
      for n2=1,w-2 do
        io.write(" ")
      end
      io.write("|")
    end
  end
end

local function textAt(x,y, str)
  term.setCursorPos(x,y)
  io.write(str)
end

local function form(str, msg, mask)
  term.clear()
  term.setCursorBlink(true)
  if msg ~= "" then
    textAt(26-(string.len(msg)/2),7,msg)
  end
  drawBox(16,9,20,3)
  textAt(14-string.len(str),10,str..":")
  local sData = inputBox(16, 18, 10, mask)
  return sData
end

local function checkPass()
  return fs.exists("ACCOUNTS.F")
end

local function loadPass()
  nUserList = 0
  aUser = {}
  aPass = {}
  local file = io.open( "ACCOUNTS.F", "r" )
  local sLineU = file:read()
  local sLineP = file:read()
  while sLineU do
    nUserList = nUserList + 1
    table.insert(aUser, sLineU)
    table.insert(aPass, sLineP)
    sLineU = file:read()
    sLineP = file:read()
  end
  file:close()
end

local function writePass()
  local file = io.open( "ACCOUNTS.F", "w" )
  for n=1,nUserList do
    file:write(aUser[n] .. "\n")
    file:write(aPass[n] .. "\n")
  end
  file:close()
end

local function login()
  local nWrong = 0
  local SFormMsg = "Please enter your username & password."
  local bCorrect = false
  local sUser
  local sPass
  while not bCorrect do
    sUser = form("Username", SFormMsg, false)
    sPass = form("Password", SFormMsg, true)
    for n=1,nUserList do
      if string.lower(sUser) == string.lower(aUser[n]) then
        if sPass == aPass[n] then
          bCorrect = true
        end
      end
    end
    if not bCorrect then
      nWrong = nWrong + 1
      if nWrong == 3 then
        msg = "Too many failed attemps! Shutting down."
        textAt(26-(string.len(msg)/2),13,msg)
        sleep(5)
        os.shutdown()
      end
      msg = "Username and/or password incorrect!"
      textAt(26-(string.len(msg)/2),13,msg)
      sleep(2)
    end
  end
  return sUser, bCorrect
end

local function newUser()
  local sUser = ""
  local sPass = ""
  local sPassconf = "!!!!!!!!!!!!!!!!!!"
  local bValid = false
  local bConflict = false
  local SFormMsg = "Account Creation: Enter new username."
  while not bValid do
    bValid = false
    sUser = ""
    while string.len(sUser) < 3 do
      sUser = form("Username", SFormMsg, false)
      if string.len(sUser) < 3 then
        SFormMsg = "Username must have at least 3 characters."
      end
      bConflict = false
      if nUserList > 0 then
        for n=1,nUserList do
          if string.lower(sUser) == string.lower(aUser[n]) then
            SFormMsg = "Username already exists! Choose another."
            bConflict = true
          end
        end
      end
      if not bConflict then
        bValid = true
      end
    end
  end
  SFormMsg = "Account Creation: Enter new  password."
  while sPass ~= sPassConf do
    while string.len(sPass) < 5 do
      sPass = form("Password", SFormMsg, true)
      if string.len(sPass) < 5 then
        SFormMsg = "Password must have at least 5 characters."
      end
    end
    SFormMsg = "Account Creation: Re-enter your password."
    sPassConf = form("Password", SFormMsg, true)
    if sPass ~= sPassConf then
      sPass = ""
      sPassconf = "!!!!!!!!!!!!!!!!!!"
      SFormMsg = "Passwords do not match! Create new password."
    end
  end
  table.insert(aPass, sPass)
  table.insert(aUser, sUser)
  nUserList = nUserList + 1
  writePass()
end

local bNotFirst = checkPass()
if bNotFirst then
  loadPass()
  x, y = login()
else
  newUser()
  x, y = login()
end

term.clear()
term.setCursorPos(1,1)
print(x)
print(y)