Part stocktake (#4069)

* Remove stat context variables

* Revert "Remove stat context variables"

This reverts commit 0989c308d0.

* Allow longer timeout for image download tests

* Create PartStocktake model

Model for representing stocktake entries against any given part

* Admin interface support for new model

* Adds API endpoint for listing stocktake information

* Bump API version

* Enable filtering and ordering for API endpoint

* Add model to permission group

* Add UI hooks for displaying stocktake data for a particular part

* Fix encoded type for 'quantity' field

* Load stocktake table for part

* Add "stocktake" button

* Add "note" field for stocktake

* Add user information when performing stocktake

* First pass at UI elements for performing stocktake

* Add user information to stocktake table

* Auto-calculate quantity based on available stock items

* add stocktake data as tabular inline (admin)

* js linting

* Add indication that a stock item has not been updated recently

* Display last stocktake information on part page

* js style fix

* Test fix for ongoing CI issues

* Add configurable option for controlling default "delete_on_deplete" behaviour

* Add id values to cells

* Hide action buttons (at least for now)

* Adds refresh button to table

* Add API endpoint to delete or edit stocktake entries

* Adds unit test for API list endpoint

* javascript linting

* More unit testing

* Add Part API filter for stocktake

* Add 'last_stocktake' field to Part model

- Gets filled out automatically when a new PartStocktake instance is created

* Update part table to include last_stocktake date

* Add simple unit test

* Fix test

InvenTree/part/serializers.py

@@ -24,14 +24,16 @@ from InvenTree.serializers import (DataFileExtractSerializer,
                                    InvenTreeDecimalField,
                                    InvenTreeImageSerializerField,
                                    InvenTreeModelSerializer,
-                                   InvenTreeMoneySerializer, RemoteImageMixin)
+                                   InvenTreeMoneySerializer, RemoteImageMixin,
+                                   UserSerializer)
 from InvenTree.status_codes import BuildStatus
 
 from .models import (BomItem, BomItemSubstitute, Part, PartAttachment,
                      PartCategory, PartCategoryParameterTemplate,
                      PartInternalPriceBreak, PartParameter,
                      PartParameterTemplate, PartPricing, PartRelated,
-                     PartSellPriceBreak, PartStar, PartTestTemplate)
+                     PartSellPriceBreak, PartStar, PartStocktake,
+                     PartTestTemplate)
 
 
 class CategorySerializer(InvenTreeModelSerializer):
@@ -451,6 +453,7 @@ class PartSerializer(RemoteImageMixin, InvenTreeModelSerializer):
             'IPN',
             'is_template',
             'keywords',
+            'last_stocktake',
             'link',
             'minimum_stock',
             'name',
@@ -504,6 +507,44 @@ class PartSerializer(RemoteImageMixin, InvenTreeModelSerializer):
         return self.instance
 
 
+class PartStocktakeSerializer(InvenTreeModelSerializer):
+    """Serializer for the PartStocktake model"""
+
+    quantity = serializers.FloatField()
+
+    user_detail = UserSerializer(source='user', read_only=True, many=False)
+
+    class Meta:
+        """Metaclass options"""
+
+        model = PartStocktake
+        fields = [
+            'pk',
+            'date',
+            'part',
+            'quantity',
+            'note',
+            'user',
+            'user_detail',
+        ]
+
+        read_only_fields = [
+            'date',
+            'user',
+        ]
+
+    def save(self):
+        """Called when this serializer is saved"""
+
+        data = self.validated_data
+
+        # Add in user information automatically
+        request = self.context['request']
+        data['user'] = request.user
+
+        super().save()
+
+
 class PartPricingSerializer(InvenTreeModelSerializer):
     """Serializer for Part pricing information"""