enable bill storing

db/index.ts

@@ -1,6 +1,7 @@
 import * as mongoose from 'mongoose'
 import Booker from './booker'
 import Booking from './booking'
+import Bill, { BillDocument } from './bill'
 import { dateFormatFrontend } from '../helpers/date'
 import { BOOKING_STATUS } from './enums'
 
@@ -82,3 +83,15 @@ export async function createBooking({
   await booking.populate('booker').execPopulate()
   return booking.toJSON()
 }
+
+export async function createBill(bookingUUID: string, billData: BillDocument) {
+  await connect()
+  const bill = new Bill(billData)
+
+  const booking = await getBookingByUUID(bookingUUID)
+  bill.booking = booking._id
+
+  await bill.save()
+  await bill.populate('booking').execPopulate()
+  return bill.toJSON()
+}