Add role-based filtering and imporve code

services/suppliers/app/services/purchase_order_service.py

@@ -464,4 +464,33 @@ class PurchaseOrderService:
         """Get most purchased inventory products"""
         return self.item_repository.get_top_purchased_inventory_products(
             tenant_id, days_back, limit
-        )
+        )
+
+    async def delete_purchase_order(self, po_id: UUID) -> bool:
+        """
+        Delete (soft delete) a purchase order
+        Only allows deletion of draft orders
+        """
+        logger.info("Deleting purchase order", po_id=str(po_id))
+
+        po = self.repository.get_by_id(po_id)
+        if not po:
+            return False
+
+        # Only allow deletion of draft orders
+        if po.status not in [PurchaseOrderStatus.DRAFT, PurchaseOrderStatus.CANCELLED]:
+            raise ValueError(
+                f"Cannot delete purchase order with status {po.status.value}. "
+                "Only draft and cancelled orders can be deleted."
+            )
+
+        # Perform soft delete
+        try:
+            self.repository.delete(po_id)
+            self.db.commit()
+            logger.info("Purchase order deleted successfully", po_id=str(po_id))
+            return True
+        except Exception as e:
+            self.db.rollback()
+            logger.error("Failed to delete purchase order", po_id=str(po_id), error=str(e))
+            raise