private void CheckModel(QuoteScheduleViewModel model)
        {
            if (model.DepositAmount > model.TotalPrice)
            {
                ModelState.AddModelError(nameof(model.DepositAmount), "Deposit cannot be greater than the total.");
            }

            if (model.DepositAmount < model.TotalPrice * 0.15m)
            {
                ModelState.AddModelError(nameof(model.DepositAmount), "Deposit amount must be greater than 15% of the total.");
            }
        }
        public ActionResult Index(QuoteScheduleViewModel model)
        {
            CheckModel(model);

            if (ModelState.IsValid)
            {
                model.Schedule = _quoteService.GenerateQuoteSchedule(
                    new QuoteServiceParameters(
                        model.SelectedLoanTerm,
                        (double)(model.TotalPrice - model.DepositAmount),
                        model.DeliveryDate));
            }

            return(View(model));
        }