Some optimizations to trade_offers to reduce loading times

trades/forms.py

@@ -29,31 +29,38 @@ class TradeAcceptanceCreateForm(forms.ModelForm):
     Expects the caller to pass:
       - trade_offer: the instance of TradeOffer this acceptance is for.
       - friend_codes: a queryset of FriendCode objects for the current user.
+      - default_friend_code (optional): the user's default FriendCode.
     It filters available requested and offered cards based on what's still available.
     """
     class Meta:
         model = TradeAcceptance
         fields = ["accepted_by", "requested_card", "offered_card"]
 
-    def __init__(self, *args, trade_offer=None, friend_codes=None, **kwargs):
+    def __init__(self, *args, trade_offer=None, friend_codes=None, default_friend_code=None, **kwargs):
         if trade_offer is None:
             raise ValueError("trade_offer must be provided to filter choices.")
         super().__init__(*args, **kwargs)
         self.trade_offer = trade_offer
 
-        # Filter accepted_by to those friend codes that belong to the current user.
         if friend_codes is None:
             raise ValueError("friend_codes must be provided")
+        # Set the accepted_by queryset to the user's friend codes.
         self.fields["accepted_by"].queryset = friend_codes
 
-        # Update active_states to include only states that mean the acceptance is still "open".
+        # If the user only has one friend code, preset the field and use a HiddenInput.
+        if friend_codes.count() == 1:
+            self.initial["accepted_by"] = friend_codes.first().pk
+            self.fields["accepted_by"].widget = forms.HiddenInput()
+        # Otherwise, if a default friend code is provided and it is in the queryset, preselect it.
+        elif default_friend_code and friend_codes.filter(pk=default_friend_code.pk).exists():
+            self.initial["accepted_by"] = default_friend_code.pk
+
+        # Update available requested_card choices from the TradeOffer's "have" side.
         active_states = [
             TradeAcceptance.AcceptanceState.ACCEPTED,
             TradeAcceptance.AcceptanceState.SENT,
             TradeAcceptance.AcceptanceState.RECEIVED,
         ]
-
-        # Build available requested_card choices from the TradeOffer's "have" side.
         available_requested_ids = []
         for through_obj in trade_offer.trade_offer_have_cards.all():
             active_count = trade_offer.acceptances.filter(
@@ -64,7 +71,7 @@ class TradeAcceptanceCreateForm(forms.ModelForm):
                 available_requested_ids.append(through_obj.card.id)
         self.fields["requested_card"].queryset = Card.objects.filter(id__in=available_requested_ids)
 
-        # Similarly, build available offered_card choices from the TradeOffer's "want" side.
+        # Update available offered_card choices from the TradeOffer's "want" side.
         available_offered_ids = []
         for through_obj in trade_offer.trade_offer_want_cards.all():
             active_count = trade_offer.acceptances.filter(