public bool Add(PurchaseBillViewModel entity)
        {
            var purchaseBill = entity.MapToPuchaseBill();

            purchaseBill.PurchaseBillId = IdUtilities.GenerateByTimeSpan();
            purchaseBill.CreatedDate    = DateTime.Now;
            purchaseBill.StaffId        = StaffGlobal.StaffId;
            _purchaseBillRepository.Add(purchaseBill);

            //purchaseBill.PurchaseBillDetails = new List<PurchaseBillDetail>();
            //var purchaseBillDetails = new List<PurchaseBillDetail>();
            foreach (var item in entity.PurchaseBillDetailViewModels)
            {
                var purchaseBillDetail = item.MapToPurchaseBillDetail();
                purchaseBillDetail.PurchaseBillId = purchaseBill.PurchaseBillId;
                _purchaseBillDetailRepository.Add(purchaseBillDetail);
            }

            return(true);
        }
        public bool Add(SaleBillViewModel entity)
        {
            if (entity == null)
            {
                return(false);
            }
            var saleBill = entity.MapToSaleBill();

            saleBill.SaleBillId  = IdUtilities.GenerateByTimeSpan();
            saleBill.CreatedDate = DateTime.Now;
            saleBill.StaffId     = StaffGlobal.CurrentStaff.StaffId;
            _saleBillRepository.Add(saleBill);
            foreach (var item in entity.SaleBillDetailViewModels)
            {
                var saleBillDetail = item.MapToSaleBillDetail();
                saleBillDetail.SaleBillId = saleBill.SaleBillId;
                _saleBillDetailRepository.Add(saleBillDetail);
            }
            return(true);
        }