fix migration

arkindex/documents/migrations/0030_remove_entity_type_metadata.py → arkindex/documents/migrations/0030_remove_entity_metatype.py

 # Generated by Django 2.2 on 2019-12-13 10:28
 
 from django.db import migrations
-from arkindex_common.enums import MetaType
+from enum import Enum
 
 
-def updateMetadata(apps, schema_editor):
-    values = set(item.value for item in MetaType)
+def remove_entity_metatype(apps, schema_editor):
     MetaData = apps.get_model('documents', 'MetaData')
-    for metadata in MetaData.objects \
-            .filter(type=MetaType.Entity) \
-            .prefetch_related('entity'):
-        metadata_type = MetaType.Text
+
+    class OldMetaType(Enum):
+        Text = 'text'
+        HTML = 'html'
+        Date = 'date'
+        Location = 'location'
+        Reference = 'reference'
+        Entity = 'entity'
+
+    values = set(item.value for item in OldMetaType)
+
+    # Don't try this at home
+    MetaData._meta.fields[2].enum = OldMetaType
+
+    for metadata in MetaData.objects.filter(type=OldMetaType.Entity).prefetch_related('entity'):
+        metadata_type = OldMetaType.Text
         if metadata.entity and metadata.entity.type.value in values:
-            metadata_type = MetaType(metadata.entity.type.value)
+            metadata_type = OldMetaType(metadata.entity.type.value)
         metadata.type = metadata_type
         metadata.save()
 
@@ -24,5 +35,8 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
-        migrations.RunPython(updateMetadata, migrations.RunPython.noop),
+        migrations.RunPython(
+            remove_entity_metatype,
+            reverse_code=migrations.RunPython.noop
+        ),
     ]