import { EasyFlow, from, on, to, finish, whenEnter } from 'node-easy-flow';

class AtmFlow extends EasyFlow {
    constructor() {
        super();

        // states
        const SHOWING_WELCOME = 'SHOWING_WELCOME',
            WAITING_FOR_PIN = 'WAITING_FOR_PIN',
            CHECKING_PIN = 'CHECKING_PIN',
            SHOWING_MAIN_MENU = 'SHOWING_MAIN_MENU',
            SHOWING_BALANCE = 'SHOWING_BALANCE',
            ...

        // events
        const cardPresent = 'cardPresent',
            pinProvided = 'pinProvided',
            pinValid = 'pinValid',
            pinInvalid = 'pinInvalid',
            cancel = 'cancel',
            menuShowBalance = 'menuShowBalance',
            switchOff = 'switchOff',
            ...

        // transition definitions
        from(SHOWING_WELCOME,
            on(cardPresent, to(WAITING_FOR_PIN,
                on(pinProvided, to(CHECKING_PIN,
                    on(pinValid, to(SHOWING_MAIN_MENU,
                        on(menuShowBalance, to(SHOWING_BALANCE,
                            on(cancel, to(SHOWING_MAIN_MENU))
                        )),
                        ...
                    )),
                    ...
                )),
                ...
            )),
            ...
        );

        // handler definitions
        whenEnter(SHOWING_WELCOME, (context) => {
            console.log('\n\n*** Welcome ***\n');
            context.invalidPinCounter = 0;
            rl.question('Select your option and press [Enter]...\n 1 Insert card\n 2 Terminate ATM\n', (option) => {
                this.trigger(option == 1 ? cardPresent : switchOff, context);
            });
        });

        whenEnter(WAITING_FOR_PIN, (context) => {
            console.log('\n\n*** Waiting for PIN ***\n');
            rl.question('Please enter your PIN and press [Enter] or just press [Enter] to cancel (current PIN is 1234)...\n', (pin) => {
                if (pin.length === 4) {
                    context.pin = pin;
                    this.trigger(pinProvided, context);
                } else {
                    this.trigger(cancel, context);
                }
            });
        });

        whenEnter(CHECKING_PIN, (context) => {
            if (context.pin == 1234) {
                this.trigger(pinValid, context);
            } else {
                context.invalidPinCounter = context.invalidPinCounter + 1 || 1;
                this.trigger(pinInvalid, context);
            }
        });

        ...
    }
}
    

let flow = new AtmFlow();
flow.start({ balance: 1000 });