Refactoring Interview v0.0.1

checkout.py

import time
import uuid


class Cart:
    @classmethod
    def get(cls, id):
        return Cart()

    def __init__(self):
        self.creator = Consumer()
        self.promotion = "$5 off"
        self.store = Store()
        self.subtotal = 5412


class Order:
    def __init__(self, cart, charge):
        self.cart = cart
        self.charge = charge
        self.email_message = "Hi, we have processed your order!"


class Delivery:
    def __init__(self, contents):
        self.contents = contents


class Consumer:
    def __init__(self):
        self.name = "Sean Yu"
        self.default_card = "4242424242424242"
        self.email = "sean@yu.com"


class Store:
    def __init__(self):
        self.order_protocol = "FAX"

    def is_open(self):
        return True


def log(str):
    print(str)


class Curl:
    MOCKS = {
        "doordash.com/dispatch/get_order_protocol_is_killed": lambda (_): False,
        "doordash.com/fee/get_fee": lambda (_): 599,
        "siftscience.com/get_checkout_fraud": lambda (_): False,
        "stripe.com/charge": lambda (params): {
            "status": 200,
            "charge": {
                "id": uuid.uuid4(),
                "card": params["card"],
                "amount": params["amount"],
            }
        },
        "mailchimp.com/emails": lambda (params): log("sending to {}:\n\n{}\n".format(params["to"], params["message"])),
    }

    @classmethod
    def get(cls, url, params):
        print("Network I/O, GET {} with {}".format(url, params))
        time.sleep(0.5)

        return Curl.MOCKS[url](params)

    @classmethod
    def post(cls, url, params):
        print("Network I/O, POST {} with {}".format(url, params))
        time.sleep(0.5)

        return Curl.MOCKS[url](params)


def checkout(cart_id,
             card,
             delivery_fee,
             ip_address,
             is_asap,
             is_consumer_pickup,
             is_depot):
    cart = Cart.get(cart_id)
    consumer = cart.creator

    if not card:
        card = consumer.default_card

    if card is None:
        print("Cart is submitted without any credit card")
        return False

    is_fraud = Curl.get("siftscience.com/get_checkout_fraud", {
        "cart": cart,
        "consumer": consumer,
        "card": card,
        "is_asap": is_asap,
        "ip_address": ip_address,
    })

    if is_fraud:
        print("Fraud!!!")
        return False

    store = cart.store
    if delivery_fee is None:
        delivery_fee = Curl.get("doordash.com/fee/get_fee", {"cart": cart})

    charge = Curl.post("stripe.com/charge", {
        "card": card,
        "amount": cart.subtotal,
    })
    order = Order(cart, charge)
    cart.charge = charge

    Curl.post("mailchimp.com/emails", {
        "message": order.email_message,
        "to": order.cart.creator.email,
    })

    return True


if __name__ == "__main__":
    checkout(1234, "1234432156788765", 399, "127.94.0.2", True, False, False)