Architecture

Logical Components

• CashModule
• CardModule
• Core

UI Modules

ATM

• Display
• Buttons
• Card Reader
• Cash Output
• Check Output

Additional

• CardHolder
• CashLoader

CardModule

Module wraps logic of working with card data

Proposed API

• readCard(cardDataModel) - loads card model into module
• checkPin(pin) - check pin, throws PinIncorrectError()
• isAuthorized() - return true if pin was correct
• getBalance() - return card balance
• updateBalance(sum) - change balance
• ...

CashModule

Wraps logic of holding money

Proposed API

• getCash(amount, nominal)
  • return money as an list(?) of notes different nominal
  • parameter amount is total sum of notes
  • parameter nominal is value from Enum(BIG, SMALL, FREE), parameter is not required
  • throws NotEnoughMoneyError

Display(DisplayView)

should have next methods

• showText(text)
• showInput(text, inputValue, hide)
  • text - text above input
  • inputValue - value of input
  • hide - if true show inputValue with ****
• showButtons(text, buttonsArray)
  • text in the middle of screen
  • buttonsArray - list of 8 items ["title1", "title2", ..., null, "title8"]