added migration for existing nutrition information

cookbook/migrations/0190_auto_20230506_2239.py

@@ -0,0 +1,40 @@
+# Generated by Django 4.1.7 on 2023-05-06 20:39
+
+from django.db import migrations
+from django_scopes import scopes_disabled
+from gettext import gettext as _
+
+
+def migrate_old_nutrition_data(apps, schema_editor):
+    print('Transforming nutrition information, this might take a while on large databases')
+    with scopes_disabled():
+        PropertyType = apps.get_model('cookbook', 'PropertyType')
+        RecipeProperty = apps.get_model('cookbook', 'RecipeProperty')
+        Recipe = apps.get_model('cookbook', 'Recipe')
+        Space = apps.get_model('cookbook', 'Space')
+
+        # TODO respect space
+        for s in Space.objects.all():
+            property_fat = PropertyType.objects.get_or_create(name=_('Fat'), unit=_('g'), space=s, )[0]
+            property_carbohydrates = PropertyType.objects.get_or_create(name=_('Carbohydrates'), unit=_('g'), space=s, )[0]
+            property_proteins = PropertyType.objects.get_or_create(name=_('Proteins'), unit=_('g'), space=s, )[0]
+            property_calories = PropertyType.objects.get_or_create(name=_('Calories'), unit=_('kcal'), space=s, )[0]
+
+            for r in Recipe.objects.filter(nutrition__isnull=False, space=s).all():
+                rp_fat = RecipeProperty.objects.create(property_type=property_fat, property_amount=r.nutrition.fats, space=s)
+                rp_carbohydrates = RecipeProperty.objects.create(property_type=property_carbohydrates, property_amount=r.nutrition.carbohydrates, space=s)
+                rp_proteins = RecipeProperty.objects.create(property_type=property_proteins, property_amount=r.nutrition.proteins, space=s)
+                rp_calories = RecipeProperty.objects.create(property_type=property_calories, property_amount=r.nutrition.calories, space=s)
+                r.properties.add(rp_fat, rp_carbohydrates, rp_proteins, rp_calories)
+                r.nutrition = None
+                r.save()
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('cookbook', '0189_foodproperty_propertytype_recipeproperty_and_more'),
+    ]
+
+    operations = [
+        migrations.RunPython(migrate_old_nutrition_data)
+    ]