.setup

local App = app.new()
App.EventHandler:disconnectAll("terminate")

App.Input = ""
App.Bleep = ""
App.Error = nil
App.Index = 1
App.Structure = {
  { Name = "Username", Filter = "[^(%a| )]", Passthrough = function(str)
    os.setComputerLabel(str)
    return str
  end },
  { Name = "Password", Bleep = true, Passthrough = md5.calc }
}
App.User = data.load("/.user")

App.EventHandler:connect("key", function(key, held)
  if key == keys.backspace then App:updateInput()
  elseif not held then
    if key == keys.enter then App:processInput()
    end
  end
end)

App.EventHandler:connect("char", function(char) App:updateInput(char) end)
App.EventHandler:connect("paste", function(paste) App:updateInput(paste) end)

function App:updateInput(str)
  self.Input = not str and string.sub(self.Input,1,-2) or self.Input..str
  self.Bleep = string.gsub(self.Input, ".", "*")
end

function App:validateInput()
  if self.Strut.filter then
    local match = string.match(self.Input, self.Strut.Filter)
    if match then return false, "Invalid character '"..match.."' found." end
  end
  return true
end

function App:processInput()
  self.Success,self.Error = self:validateInput()
  if not self.Success then return end
  self.User[self.Strut.Name] = self.Strut.Passthrough and self.Strut.Passthrough(self.Input) or self.Input
  self.Index = self.Index + 1
  if self.Index <= #self.Structure then return self:fetchInput() end
  self:stop()
end

function App:fetchInput()
  self.Strut = self.Structure[self.Index]
  self.Input = (not self.User[self.Strut.Name] or self.Strut.Passthrough) and "" or self.User[self.Strut.Name]
  self.Bleep = string.gsub(self.Input, ".", "*")
  self.Error = nil
end

function App:draw()
  term.setTextColor(_G.TextColor)
  term.setBackgroundColor(_G.BackgroundColor)
  term.clear()
  term.setCursorPos(1,1)
  term.write(self.Strut.Name)
  term.write("> ")
  term.write(self.Strut.Bleep and self.Bleep or self.Input)
  if self.Error then
    term.setTextColor(colors.red)
    term.setCursorPos(1,2)
    term.write(self.Error)
  end
end

function App:stopped()
  data.save("/.user", self.User)
  os.reboot()
end

App:fetchInput()
App:start()