further work on billing

db/bill.ts

@@ -1,6 +1,5 @@
 import * as mongoose from 'mongoose'
 import { BILL_STATUS, MILAGE_RATES, getMilageRateValue } from './enums'
-import { BookingDocument } from './booking'
 
 export interface AdditionalCosts {
   name: string
@@ -10,7 +9,6 @@ export interface AdditionalCosts {
 export interface BillDocument
   extends mongoose.SchemaTimestampsConfig,
     mongoose.Document {
-  booking: BookingDocument
   milageStart: number
   milageEnd: number
   milage?: number
@@ -23,12 +21,6 @@ export interface BillModel extends mongoose.Model<BillDocument> {}
 
 const BillSchema = new mongoose.Schema<BillDocument>(
   {
-    booking: {
-      type: mongoose.Schema.Types.ObjectId,
-      ref: 'Booking',
-      unique: true,
-      required: true,
-    },
     milageStart: {
       type: Number,
       required: true,