uncloud/uncloud_pay/stripe.py

import stripe
import stripe.error
import logging
import datetime

from django.core.exceptions import ObjectDoesNotExist, ValidationError
from django.conf import settings
from django.contrib.auth import get_user_model

from .models import StripeCustomer, StripeCreditCard

logger = logging.getLogger(__name__)

CURRENCY = 'chf'

stripe.api_key = settings.STRIPE_KEY

def handle_stripe_error(f):
    def handle_problems(*args, **kwargs):
        response = {
            'paid': False,
            'response_object': None,
            'error': None
        }

        common_message = "Currently it is not possible to make payments. Please try agin later."
        try:
            response_object = f(*args, **kwargs)
            return response_object
        except stripe.error.CardError as e:
            # Since it's a decline, stripe.error.CardError will be caught
            body = e.json_body
            logging.error(str(e))

            raise e # For error handling.
        except stripe.error.RateLimitError:
            logging.error("Too many requests made to the API too quickly.")
            raise Exception(common_message)
        except stripe.error.InvalidRequestError as e:
            logging.error(str(e))
            raise Exception('Invalid parameters.')
        except stripe.error.AuthenticationError as e:
            # Authentication with Stripe's API failed
            # (maybe you changed API keys recently)
            logging.error(str(e))
            raise Exception(common_message)
        except stripe.error.APIConnectionError as e:
            logging.error(str(e))
            raise Exception(common_message)
        except stripe.error.StripeError as e:
            # XXX: maybe send email
            logging.error(str(e))
            raise Exception(common_message)

    return handle_problems

def public_api_key():
    return settings.STRIPE_PUBLIC_KEY

def get_customer_id_for(user):
    try:
        # .get() raise if there is no matching entry.
        return StripeCustomer.objects.get(owner=user).stripe_id
    except ObjectDoesNotExist:
        # No entry yet - making a new one.
        try:
            customer = create_customer(user.username, user.email)
            uncloud_stripe_mapping = StripeCustomer.objects.create(
                    owner=user, stripe_id=customer.id)
            return uncloud_stripe_mapping.stripe_id
        except Exception as e:
            return None

@handle_stripe_error
def create_setup_intent(customer_id):
    return stripe.SetupIntent.create(customer=customer_id)

@handle_stripe_error
def get_setup_intent(setup_intent_id):
    return stripe.SetupIntent.retrieve(setup_intent_id)

@handle_stripe_error
def get_payment_method(payment_method_id):
    return stripe.PaymentMethod.retrieve(payment_method_id)

@handle_stripe_error
def get_card_from_payment(user, payment_method_id):
    payment_method = stripe.PaymentMethod.retrieve(payment_method_id)
    if payment_method:
        if 'card' in payment_method:
            sync_cards_for_user(user)
            return payment_method['card']
    return False


@handle_stripe_error
def attach_payment_method(payment_method_id, user):
    customer_id = get_customer_id_for(user)
    ret = stripe.PaymentMethod.attach(payment_method_id, customer=customer_id)
    sync_cards_for_user(user)
    return ret

@handle_stripe_error
def create_customer(name, email):
    return stripe.Customer.create(name=name, email=email)

@handle_stripe_error
def get_customer(customer_id):
    return stripe.Customer.retrieve(customer_id)

@handle_stripe_error
def get_customer_cards(customer_id):

    cards = []
    stripe_cards = stripe.PaymentMethod.list(
        customer=customer_id,
        type="card",
    )

    for stripe_card in stripe_cards["data"]:
        card = {}
        card['brand'] = stripe_card["card"]["brand"]
        card['last4'] = stripe_card["card"]["last4"]
        card['month'] = stripe_card["card"]["exp_month"]
        card['year']  = stripe_card["card"]["exp_year"]
        card['id']    = stripe_card["id"]

        cards.append(card)

    return cards

@handle_stripe_error
def delete_card(card_id):
    return stripe.PaymentMethod.detach(card_id)

def sync_cards_for_user(user):
    customer_id = get_customer_id_for(user)
    cards = get_customer_cards(customer_id)

    active_cards = StripeCreditCard.objects.filter(owner=user,
                                                   active=True)

    if len(active_cards) > 0:
        has_active_card = True
    else:
        has_active_card = False

    for card in cards:
        active = False

        if not has_active_card:
            active = True
            has_active_card = True

        StripeCreditCard.objects.get_or_create(card_id=card['id'],
                                               owner = user,
                                               defaults = {
                                                   'last4': card['last4'],
                                                   'brand': card['brand'],
                                                   'expiry_date': datetime.date(card['year'],
                                                                                card['month'],
                                                                                1),
                                                   'active': active
                                                   }
                                               )

@handle_stripe_error
def charge_customer(user, amount, currency='CHF', card=False):
    # Amount is in CHF but stripes requires smallest possible unit.
    # https://stripe.com/docs/api/payment_intents/create#create_payment_intent-amount
    # FIXME: might need to be adjusted for other currencies

    if currency == 'CHF':
        adjusted_amount = int(amount * 100)
    else:
        return Exception("Programming error: unsupported currency")

    try:
        card = card or StripeCreditCard.objects.get(owner=user,
                                     active=True)

    except StripeCreditCard.DoesNotExist:
        raise ValidationError("No active credit card - cannot create payment")

    customer_id = get_customer_id_for(user)
    
    return stripe.PaymentIntent.create(
        amount=adjusted_amount,
        currency=currency,
        customer=customer_id,
        payment_method=card.card_id,
        off_session=True,
        confirm=True,
    )

@handle_stripe_error
def get_payment_intent(user, amount, currency='CHF', card=False):
    # Amount is in CHF but stripes requires smallest possible unit.
    # https://stripe.com/docs/api/payment_intents/create#create_payment_intent-amount
    # FIXME: might need to be adjusted for other currencies

    if currency == 'CHF':
        adjusted_amount = int(amount * 100)
    else:
        return Exception("Programming error: unsupported currency")

    try:
        card = card or StripeCreditCard.objects.get(owner=user,
                                     active=True)

    except StripeCreditCard.DoesNotExist:
        raise ValidationError("No active credit card - cannot create payment")

    customer_id = get_customer_id_for(user)
    
    return stripe.PaymentIntent.create(
        amount=adjusted_amount,
        currency=currency,
        customer=customer_id,
        payment_method=card.card_id,
        setup_future_usage='off_session',
        confirm=False,
    )

@handle_stripe_error
def get_or_create_tax_id_for_user(stripe_customer_id, vat_number,
                                      type="eu_vat", country=""):
    def compare_vat_numbers(vat1, vat2):
        _vat1 = vat1.replace(" ", "").replace(".", "").replace("-","")
        _vat2 = vat2.replace(" ", "").replace(".", "").replace("-","")
        return True if _vat1 == _vat2 else False

    tax_ids_list = stripe.Customer.list_tax_ids(
        stripe_customer_id,
        limit=100,
    )
    for tax_id_obj in tax_ids_list.data:
        if compare_vat_numbers(tax_id_obj.value, vat_number):
            return tax_id_obj
        else:
            logger.debug(
                "{val1} is not equal to {val2} or {con1} not same as "
                "{con2}".format(val1=tax_id_obj.value, val2=vat_number,
                                con1=tax_id_obj.country.lower(),
                                con2=country.lower().strip()))
    logger.debug(
        "tax id obj does not exist for {val}. Creating a new one".format(
            val=vat_number
        ))
    tax_id_obj = stripe.Customer.create_tax_id(
        stripe_customer_id,
        type=type,
        value=vat_number,
    )
    return tax_id_obj