update link registration site to executive dashboard

backend/apps/farms/migrations/0019_site_pusat_fields.py

@@ -0,0 +1,52 @@
+# Move pusat registration fields onto sites; drop pusat_registrations.
+
+from django.db import migrations, models
+
+
+def forwards_copy_registrations(apps, schema_editor):
+    Site = apps.get_model("farms", "Site")
+    PusatRegistration = apps.get_model("farms", "PusatRegistration")
+    for row in PusatRegistration.objects.select_related("site").all():
+        site = row.site
+        site.pusat_code = row.code or ""
+        site.pusat_active_site_id = row.active_site_id
+        site.pusat_registered_at = row.registered_at
+        site.save(
+            update_fields=[
+                "pusat_code",
+                "pusat_active_site_id",
+                "pusat_registered_at",
+                "updated_at",
+            ]
+        )
+
+
+def noop_reverse(apps, schema_editor):
+    raise RuntimeError("Cannot reverse pusat fields onto sites.")
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("farms", "0018_site_id_numeric_suffix"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="site",
+            name="pusat_code",
+            field=models.SlugField(blank=True, default="", max_length=64),
+        ),
+        migrations.AddField(
+            model_name="site",
+            name="pusat_active_site_id",
+            field=models.BigIntegerField(blank=True, null=True),
+        ),
+        migrations.AddField(
+            model_name="site",
+            name="pusat_registered_at",
+            field=models.DateTimeField(blank=True, null=True),
+        ),
+        migrations.RunPython(forwards_copy_registrations, noop_reverse),
+        migrations.DeleteModel(name="PusatRegistration"),
+    ]