Ensure an account only has one strategy with active management

core/forms.py

@@ -217,6 +217,21 @@ class StrategyForm(RestrictedFormMixin, ModelForm):
                     ]
                 )
         if cleaned_data.get("active_management_enabled"):
+            # Ensure that no other strategy with this account has active management enabled
+            if (
+                Strategy.objects.filter(
+                    account=cleaned_data.get("account"),
+                    active_management_enabled=True,
+                    enabled=True,
+                )
+                .exclude(id=self.instance.id)
+                .exists()
+            ):
+                self.add_error(
+                    "active_management_enabled",
+                    "You cannot have more than one strategy with active management enabled for the same account.",
+                )
+                return
             if not cleaned_data.get("active_management_policy"):
                 self.add_error(
                     "active_management_policy",