[#3793] Change payment reference number

The internal order ID isn't relevant anywore, instead we rely
on the PK of the model. The race condition handling is also
not relevant anymore as we rely on the PK which is already supposed
to be unique.

Author: Viicos

src/openforms/payments/models.py

@@ -1,9 +1,11 @@
+from __future__ import annotations
+
 import uuid
 from decimal import Decimal
 from typing import TYPE_CHECKING
 
-from django.db import IntegrityError, models, transaction
-from django.db.models import Max, Sum
+from django.db import models, transaction
+from django.db.models import Sum
 from django.utils.translation import gettext_lazy as _
 
 from openforms.plugins.constants import UNIQUE_ID_MAX_LENGTH
@@ -14,18 +16,15 @@
 if TYPE_CHECKING:
     from openforms.submissions.models import Submission
 
-ORDER_ID_START = 100
-ORDER_ID_PAD_LENGTH = 6
-
 
-class SubmissionPaymentManager(models.Manager):
+class SubmissionPaymentManager(models.Manager["SubmissionPayment"]):
     def create_for(
         self,
-        submission: "Submission",
+        submission: Submission,
         plugin_id: str,
         plugin_options: dict,
         amount: Decimal,
-    ):
+    ) -> SubmissionPayment:
         assert isinstance(amount, Decimal)
 
         # first create without order_id
@@ -36,37 +35,27 @@ def create_for(
             amount=amount,
         )
         # then update with a unique order_id
-        while True:
-            try:
-                with transaction.atomic():
-                    payment.order_id = self.get_next_order_id()
-                    payment.public_order_id = self.create_public_order_id_for(payment)
-                    payment.save(update_fields=("order_id", "public_order_id"))
-                    break
-            except IntegrityError:
-                # race condition on unique order_id
-                continue
-        return payment
 
-    def get_next_order_id(self) -> int:
-        agg = self.aggregate(Max("order_id"))
-        max_order_id = agg["order_id__max"] or ORDER_ID_START
-        return max_order_id + 1
+        with transaction.atomic():
+            payment.public_order_id = self.create_public_order_id_for(payment)
+            payment.save(update_fields=("public_order_id",))
+
+        return payment
 
     @staticmethod
-    def create_public_order_id_for(payment: "SubmissionPayment") -> str:
+    def create_public_order_id_for(payment: SubmissionPayment) -> str:
         config = GlobalConfiguration.get_solo()
-        prefix = config.payment_order_id_prefix
-        prefix = prefix.replace("{year}", str(payment.created.year))
-        order_id = str(payment.order_id).rjust(ORDER_ID_PAD_LENGTH, "0")
-        return prefix + order_id
+        prefix = config.payment_order_id_prefix.format(year=payment.created.year)
+        return (
+            f"{prefix}_{payment.submission.public_registration_reference}_{payment.pk}"
+        )
 
 
-class SubmissionPaymentQuerySet(models.QuerySet):
+class SubmissionPaymentQuerySet(models.QuerySet["SubmissionPayment"]):
     def sum_amount(self) -> Decimal:
         return self.aggregate(sum_amount=Sum("amount"))["sum_amount"] or Decimal("0")
 
-    def get_completed_public_order_ids(self) -> list[int]:
+    def get_completed_public_order_ids(self) -> list[str]:
         return list(
             self.filter(
                 status__in=(PaymentStatus.registered, PaymentStatus.completed)
@@ -88,17 +77,16 @@ class SubmissionPayment(models.Model):
         null=True,
         help_text=_("Copy of payment options at time of initializing payment."),
     )
-    order_id = models.BigIntegerField(
-        _("Order ID (internal)"),
-        unique=True,
-        null=True,
-        help_text=_("Unique tracking across backend"),
-    )
+    # TODO Django 5.2 Update to a `GeneratedField`
     public_order_id = models.CharField(
         _("Order ID"),
         max_length=32,
         blank=True,
-        help_text=_("Order ID stored with payment provider."),
+        help_text=_(
+            "The order ID to be sent to the payment provider. This ID is built by "
+            "concatenating an optional global prefix, the submission public reference "
+            "and a unique incrementing ID."
+        ),
     )
     amount = models.DecimalField(
         _("payment amount"),
@@ -127,8 +115,8 @@ class Meta:
             )
         ]
 
-    def __str__(self):
-        return f"#{self.order_id} '{self.get_status_display()}' {self.amount}"
+    def __str__(self) -> str:
+        return f"#{self.public_order_id} '{self.get_status_display()}' {self.amount}"
 
     @property
     def form(self):