fix(market): per-event bet loss+win

polylan_submitter/market/models.py

@@ -1,10 +1,28 @@
 import uuid
 from django.db import models
+from django.db.models import Sum
 
 from events.models import Event
 from events.scoping import EventScopedManager
 
 
+# Each event's market starts every user with this balance
+STARTING_POINTS = 1000
+
+
+def get_event_points(user, event) -> int:
+    """User's market balance for an event: starting points + the event's point changes.
+
+    BET_LOST rows are informational (the stake was already deducted by BET_PLACED).
+    """
+    total = (
+        UserPointChange.objects.filter(user=user, market__event=event)
+        .exclude(reason=UserPointChange.Reason.BET_LOST)
+        .aggregate(total=Sum("amount"))["total"]
+    )
+    return STARTING_POINTS + (total or 0)
+
+
 class BaseModel(models.Model):
     uuid = models.UUIDField(default=uuid.uuid4, unique=True, editable=False)
     created_at = models.DateTimeField(auto_now_add=True)