Some optimizations to trade_offers to reduce loading times

cards/models.py

@@ -1,4 +1,6 @@
 from django.db import models
+from django.db.models import Prefetch
+from django.apps import apps
 
 class DeckNameTranslation(models.Model):
   id = models.AutoField(primary_key=True)
@@ -55,6 +57,7 @@ class Deck(models.Model):
 
 class Rarity(models.Model):
   id = models.AutoField(primary_key=True)
+  normalized_id = models.IntegerField(null=False)
   name = models.CharField(max_length=64)
   icons = models.CharField(max_length=64)
   created_at = models.DateTimeField(auto_now_add=True)
@@ -63,14 +66,26 @@ class Rarity(models.Model):
   def __str__(self):
     return self.name
 
-  @property
-  def normalized_id(self):
-    """
-    For trading equivalence: treat Special Art Rare (pk 7) and Super Rare (pk 6) as the same.
-    """
-    if self.pk in (6, 7):
-      return 6
-    return self.pk
+# Custom Manager for Card model
+class CardPrefetchManager(models.Manager):
+    def get_queryset(self):
+        return (
+            super()
+            .get_queryset()
+            .select_related("cardset", "rarity")
+            .prefetch_related(
+                "decks",
+                "decks__cardset",
+            )
+        )
+
+class CardManager(models.Manager):
+    def get_queryset(self):
+        return (
+            super()
+            .get_queryset()
+            .select_related("cardset", "rarity")
+        )
 
 class Card(models.Model):
   id = models.AutoField(primary_key=True)
@@ -82,6 +97,10 @@ class Card(models.Model):
   created_at = models.DateTimeField(auto_now_add=True)
   updated_at = models.DateTimeField(auto_now=True)
 
+  # Use the custom manager to ensure optimized querysets everywhere.
+  objects = CardPrefetchManager()
+  objects_no_prefetch = CardManager()
+
   def __str__(self):
     # For display, we show the original rarity icons.
     return f"{self.name} {self.rarity.icons} {self.cardset.name}"