corporate: Adjust models for RemoteRealm customers.

corporate/migrations/0020_add_remote_realm_customers.py

@@ -0,0 +1,37 @@
+# Generated by Django 4.2.7 on 2023-11-17 20:11
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("zilencer", "0035_remoterealmcount_remote_realm_and_more"),
+        ("corporate", "0019_zulipsponsorshiprequest_expected_total_users_and_more"),
+    ]
+
+    operations = [
+        migrations.RemoveConstraint(
+            model_name="customer",
+            name="cloud_xor_self_hosted",
+        ),
+        migrations.AddField(
+            model_name="customer",
+            name="remote_realm",
+            field=models.OneToOneField(
+                null=True, on_delete=django.db.models.deletion.CASCADE, to="zilencer.remoterealm"
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name="customer",
+            constraint=models.CheckConstraint(
+                check=models.Q(
+                    ("realm__isnull", False),
+                    ("remote_server__isnull", False),
+                    ("remote_realm__isnull", False),
+                    _connector="OR",
+                ),
+                name="has_associated_model_object",
+            ),
+        ),
+    ]

corporate/models.py

@@ -17,8 +17,12 @@ class Customer(models.Model):
     and the active plan, if any.
     """
 
+    # The actual model object that this customer is associated
+    # with. Exactly one of the following will be non-null.
     realm = models.OneToOneField(Realm, on_delete=CASCADE, null=True)
+    remote_realm = models.OneToOneField(RemoteRealm, on_delete=CASCADE, null=True)
     remote_server = models.OneToOneField(RemoteZulipServer, on_delete=CASCADE, null=True)
+
     stripe_customer_id = models.CharField(max_length=255, null=True, unique=True)
     sponsorship_pending = models.BooleanField(default=False)
     # A percentage, like 85.
@@ -30,10 +34,13 @@ class Customer(models.Model):
     exempt_from_license_number_check = models.BooleanField(default=False)
 
     class Meta:
+        # Enforce that at least one of these is set.
         constraints = [
             models.CheckConstraint(
-                check=Q(realm__isnull=False) ^ Q(remote_server__isnull=False),
-                name="cloud_xor_self_hosted",
+                check=Q(realm__isnull=False)
+                | Q(remote_server__isnull=False)
+                | Q(remote_realm__isnull=False),
+                name="has_associated_model_object",
             )
         ]