♻️ [#46] -- refactor data migrations

zgw_consumers/migrations/0016_auto_20220818_1412.py

@@ -3,35 +3,27 @@
 from django.db import migrations, models
 
 
-def change_certificate_model(new_model, old_model):
-    OldCertificate = old_model
-    NewCertificate = new_model
+def get_operation(forwards: bool = True):
+    from_app = "zgw_consumers" if forwards else "simple_certmanager"
+    to_app = "simple_certmanager" if forwards else "zgw_consumers"
 
-    old_certs = OldCertificate.objects.all()
+    def migrate_data(apps, _):
+        NewCertificate = apps.get_model(to_app, "Certificate")
+        OldCertificate = apps.get_model(from_app, "Certificate")
 
-    for old_cert in old_certs:
-        new_cert = NewCertificate(
-            id=old_cert.id,
-            label=old_cert.label,
-            type=old_cert.type,
-            public_certificate=old_cert.public_certificate,
-            private_key=old_cert.private_key,
-        )
-        new_cert.save()
+        old_certs = OldCertificate.objects.all()
 
+        for old_cert in old_certs:
+            new_cert = NewCertificate(
+                id=old_cert.id,
+                label=old_cert.label,
+                type=old_cert.type,
+                public_certificate=old_cert.public_certificate,
+                private_key=old_cert.private_key,
+            )
+            new_cert.save()
 
-def migrate_certificate_forward(apps, _):
-    change_certificate_model(
-        new_model=apps.get_model("simple_certmanager", "Certificate"),
-        old_model=apps.get_model("zgw_consumers", "Certificate"),
-    )
-
-
-def migrate_certificate_backward(apps, _):
-    change_certificate_model(
-        new_model=apps.get_model("zgw_consumers", "Certificate"),
-        old_model=apps.get_model("simple_certmanager", "Certificate"),
-    )
+    return migrate_data
 
 
 class Migration(migrations.Migration):
@@ -42,7 +34,7 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
-        migrations.RunPython(migrate_certificate_forward, migrations.RunPython.noop),
+        migrations.RunPython(get_operation(forwards=True), migrations.RunPython.noop),
         migrations.AlterField(
             model_name="service",
             name="client_certificate",
@@ -67,5 +59,5 @@ class Migration(migrations.Migration):
                 to="simple_certmanager.certificate",
             ),
         ),
-        migrations.RunPython(migrations.RunPython.noop, migrate_certificate_backward),
+        migrations.RunPython(migrations.RunPython.noop, get_operation(forwards=False)),
     ]