JourneyJoker/payment/models/invoice.py

from django.db import models
from django.contrib.auth import get_user_model
from django.core.files.base import ContentFile
from django.utils import timezone
from django.conf import settings

import uuid

from dbsettings.functions import getValue

from auction.models import Inquiry

from .billingaddress import BillingAddress

from ..functions import invoice_upload_path
from ..pdfviews import InvoicePDFView

class InvoiceTypeChoices(models.IntegerChoices):
    INVOICE = (0, "Rechnung")
    DEPOSIT = (1, "Sicherheitsleistung")

class Invoice(models.Model):
    uuid = models.UUIDField(default=uuid.uuid4)
    user = models.ForeignKey(get_user_model(), models.PROTECT)
    billing_address = models.ForeignKey(BillingAddress, models.PROTECT)
    currency = models.CharField(max_length=3)
    tax_rate = models.DecimalField(max_digits=4, decimal_places=2)
    invoice = models.FileField(null=True, blank=True, upload_to=invoice_upload_path)
    inquiry = models.OneToOneField(Inquiry, null=True, blank=True, on_delete=models.SET_NULL)
    created = models.DateTimeField(auto_now_add=True)
    type = models.IntegerField(choices=InvoiceTypeChoices.choices, default=1)

    @property
    def price_net(self):
        price = 0

        for item in self.invoiceitem_set.all():
            price += item.net_total

        return price

    @property
    def tax(self):
        return round(self.price_net * self.tax_rate / 100, 2)

    @property
    def price_gross(self):
        return self.price_net + self.tax

    @property
    def payment_instructions(self):
        return None

    @property
    def url(self):
        try:
            return self.invoice.url
        except:
            return False

    @property
    def balance(self):
        paid_amount = 0

        for payment in self.invoicepayment_set.all():
            paid_amount += payment.amount

        return paid_amount - self.price_gross

    @property
    def is_paid(self):
        return self.balance >= 0

    def finalize(self, *args, **kwargs):
        if self.is_paid:
            try:
                self.inquiry.process_payment(*args, **kwargs)
            except Inquiry.DoesNotExist:
                pass

            self.generate_invoice()

    def generate_invoice(self):
        view = InvoicePDFView()

        bottom_tip = (f"{ self.payment_instructions }<br /><br />" if self.payment_instructions else "") + getValue("billing.bottom_tip", "")
        bottom_tip += "<br />" if bottom_tip else ""
        bottom_tip +=  "Dokument erstellt: %s" % str(timezone.now())

        args = {
            "type": InvoiceTypeChoices._value2label_map_[self.type],
            "object": self,
            "bottom_tip": bottom_tip
        }

        self.invoice = ContentFile(view.render(**args), "invoice.pdf")
        self.save()

    @classmethod
    def from_inquiry(cls, inquiry):
        invoice = cls.objects.create(
            user = inquiry.client.user,
            billing_address = BillingAddress.from_profile(inquiry.client),
            currency = settings.CURRENCY_CODE,
            tax_rate = 0,
            inquiry = inquiry
        )

        invoice.invoiceitem_set.create(
            name = "SL",
            description = "Rückzahlbare Sicherheitsleistung zu JourneyJoker-Anfrage #%i" % inquiry.id,
            count = 1,
            net_each = inquiry.budget
        )

        return invoice