first commit

backend/app/services/case_service.py

@@ -0,0 +1,23 @@
+from uuid import UUID
+from decimal import Decimal
+
+from sqlalchemy import select, func
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.case import Case
+from app.models.assessment import FraudAssessment, ReviewStatus
+
+
+async def recalculate_case_total(case_id: UUID, db: AsyncSession) -> float:
+    """Recalculate and persist the total confirmed fraud amount for a case."""
+    result = await db.execute(
+        select(func.coalesce(func.sum(FraudAssessment.assessed_amount), 0))
+        .where(FraudAssessment.case_id == case_id)
+        .where(FraudAssessment.review_status == ReviewStatus.confirmed)
+    )
+    total = float(result.scalar() or 0)
+    case = await db.get(Case, case_id)
+    if case:
+        case.total_amount = total
+        await db.flush()
+    return total