use DTO object, and cleanup some code which is no longer needed

cookbook/connectors/connector.py

@@ -1,6 +1,43 @@
 from abc import ABC, abstractmethod
+from dataclasses import dataclass
+from typing import Optional
 
-from cookbook.models import ShoppingListEntry, Space, ConnectorConfig
+from cookbook.models import ShoppingListEntry, User, ConnectorConfig
+
+
+@dataclass
+class UserDTO:
+    username: str
+    first_name: Optional[str]
+
+    @staticmethod
+    def try_create_from_user(instance: Optional[User]) -> 'UserDTO':
+        return UserDTO(
+            username=instance.username,
+            first_name=instance.first_name if instance.first_name and len(instance.first_name) > 0 else None
+        )
+
+
+@dataclass
+class ShoppingListEntryDTO:
+    food_name: str
+    amount: Optional[float]
+    base_unit: Optional[str]
+    unit_name: Optional[str]
+    created_by: UserDTO
+
+    @staticmethod
+    def try_create_from_entry(instance: ShoppingListEntry) -> Optional['ShoppingListEntryDTO']:
+        if instance.food is None or instance.created_by is None:
+            return None
+
+        return ShoppingListEntryDTO(
+            food_name=instance.food.name,
+            amount=instance.amount if instance.amount and instance.amount > 0 else None,
+            unit_name=instance.unit.name if instance.unit else None,
+            base_unit=instance.unit.base_unit if instance.unit and instance.unit.base_unit and len(instance.unit.base_unit) > 0 else None,
+            created_by=UserDTO.try_create_from_user(instance.created_by),
+        )
 
 
 # A Connector is 'destroyed' & recreated each time 'any' ConnectorConfig in a space changes.
@@ -10,20 +47,18 @@ class Connector(ABC):
         pass
 
     @abstractmethod
-    async def on_shopping_list_entry_created(self, space: Space, instance: ShoppingListEntry) -> None:
+    async def on_shopping_list_entry_created(self, instance: ShoppingListEntryDTO) -> None:
         pass
 
     # This method might not trigger on 'direct' entry updates: https://stackoverflow.com/a/35238823
     @abstractmethod
-    async def on_shopping_list_entry_updated(self, space: Space, instance: ShoppingListEntry) -> None:
+    async def on_shopping_list_entry_updated(self, instance: ShoppingListEntryDTO) -> None:
         pass
 
     @abstractmethod
-    async def on_shopping_list_entry_deleted(self, space: Space, instance: ShoppingListEntry) -> None:
+    async def on_shopping_list_entry_deleted(self, instance: ShoppingListEntryDTO) -> None:
         pass
 
     @abstractmethod
     async def close(self) -> None:
         pass
-
-    # TODO: Add Recipes & possibly Meal Place listeners/hooks (And maybe more?)