use fixed tarifs and add additional costs

db/bill.ts

@@ -1,7 +1,8 @@
 import * as mongoose from 'mongoose'
-import { BILL_STATUS, MILAGE_RATES, getMilageRateValue } from './enums'
+import { BILL_STATUS, MILAGE_TARIFS } from './enums'
+import { getBillTotal } from '../helpers/bill'
 
-export interface AdditionalCosts {
+export interface AdditionalCost {
   name: string
   value: number
 }
@@ -12,9 +13,9 @@ export interface BillDocument
   milageStart: number
   milageEnd: number
   milage?: number
-  rate: MILAGE_RATES
+  tarif: MILAGE_TARIFS
   status: BILL_STATUS
-  additionalCosts: AdditionalCosts[]
+  additionalCosts: AdditionalCost[]
 }
 
 export interface BillModel extends mongoose.Model<BillDocument> {}
@@ -46,10 +47,10 @@ const BillSchema = new mongoose.Schema<BillDocument>(
         message: (props) => `${props.value} is smaller than milageStart!`,
       },
     },
-    rate: {
+    tarif: {
       type: String,
-      enum: Object.values(MILAGE_RATES),
-      default: MILAGE_RATES.EXTERN_LTE_200,
+      enum: Object.values(MILAGE_TARIFS),
+      default: MILAGE_TARIFS.EXTERN,
       required: true,
     },
     additionalCosts: [
@@ -79,13 +80,7 @@ BillSchema.virtual('milage').get(function () {
 BillSchema.virtual('total').get(function () {
   const bill = this as BillDocument
 
-  const milageCosts =
-    Math.round(bill.milage * getMilageRateValue(bill.rate) * 100) / 100
-  const additionalCostSum = bill.additionalCosts
-    .map(({ value }) => value)
-    .reduce((acc, value) => acc + value, 0)
-
-  return milageCosts + additionalCostSum
+  return getBillTotal(bill)
 })
 
 export default <BillModel>mongoose.models.Bill ||