Jadikan nol bila nilai tagihan negatif

sismiop/services/base.py

@@ -220,7 +220,10 @@ class Inquiry(Query):
         denda_lalu = bayar.denda_sppt or 0
         denda_lalu = bayar.denda_sppt or 0
         sisa = float(self.total_bayar - denda_lalu)
         sisa = float(self.total_bayar - denda_lalu)
         tagihan = self.invoice.pbb_yg_harus_dibayar_sppt - sisa
         tagihan = self.invoice.pbb_yg_harus_dibayar_sppt - sisa
-        self.tagihan = round_up(tagihan)
+        if tagihan < 0:
+            self.tagihan = 0
+        else:
+            self.tagihan = round_up(tagihan)
 
 
     def hitung_denda(self):
     def hitung_denda(self):
         if isinstance(self.tgl_bayar, datetime):
         if isinstance(self.tgl_bayar, datetime):