import { Injectable } from '@angular/core';
import { ActivatedRouteSnapshot, Resolve } from '@angular/router';
import { Observable } from 'rxjs';

import { Bill } from './bill';
import { VoucherService } from './voucher.service';

@Injectable({
  providedIn: 'root',
})
export class BillResolver implements Resolve<Bill> {
  constructor(private ser: VoucherService) {}

  resolve(route: ActivatedRouteSnapshot): Observable<Bill> {
    const tableId = route.queryParamMap.get('table');
    const guestId = route.queryParamMap.get('guest');
    const voucherId = route.queryParamMap.get('voucher');
    const billId = route.queryParamMap.get('bill');
    if (billId !== null) {
      return this.ser.getFromBill(billId);
    }
    if (tableId !== null) {
      return this.ser.getFromTable(tableId as string, voucherId, guestId);
    }
    if (voucherId !== null) {
      return this.ser.getFromId(voucherId);
    }
    throw new Error('Unable to get bill');
  }
}