public IActionResult CloseDay([FromBody] DataContracts.Requests.DaySlip contract) { var openedOrders = orderBook.GetAll(); if (openedOrders.Any()) { return(BadRequest("OpenedOrdersPending")); } var openedBills = billBook.GetAll(); if (openedBills.Any()) { return(BadRequest("OpenedBillsPending")); } var day = calendar.Get(contract.Day); if (day == null) { return(BadRequest("DayNotOpened")); } if (day.Closed) { return(BadRequest("DayAlreadyClosed")); } var daySlip = contract.ToDaySlip(day); daySlipBook.Add(daySlip); day.Close(); calendar.Update(day); return(Ok()); }