JourneyJoker/payment/sepa/models.py

from payment.models import InvoicePayment, Invoice

from django.db import models

import random
import string

from .functions import generate_reference

class SepaPaymentReference(models.Model):
    invoice = models.ForeignKey(Invoice, models.CASCADE)
    reference = models.IntegerField(default=generate_reference)

    def create_payment(self, amount):
        return SepaInvoicePayment.objects.create(invoice=self.invoice, gateway_id=self.reference, amount=amount)

class SepaInvoicePayment(InvoicePayment):
    @property
    def gateway(self):
        return "Bank Transfer"

    @staticmethod
    def initiate(subscription):
        SepaPaymentReference.objects.get_or_create(subscription=subscription)