using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using Tanshu.Accounts.Contracts;
using Tanshu.Accounts.Entities;
using Tanshu.Accounts.Helpers;
using Tanshu.Accounts.Print;
using Tanshu.Accounts.Repository;
using Tanshu.Common;
using System;

namespace Tanshu.Accounts.PointOfSale
{
    public class BillController
    {
        private readonly BillDict _bill;
        private Voucher _billInfo;
        private Guid? _editVoucherID;
        private readonly bool _print;
        private ISaleForm _saleForm;

        public Waiter Waiter
        {
            get { return _billInfo.Waiter; }
            set { _billInfo.Waiter = value; }
        }
        public BillController(Guid? editVoucherID, bool print)
        {
            this._editVoucherID = editVoucherID;
            _print = print;
            _bill = new BillDict();
            _billInfo = new Voucher(Session.User);
            using (var bi = new CustomerBI())
                _billInfo.Customer = bi.Get(x => x.CustomerID == Constants.CASH_CUSTOMER);
            using (var bi = new WaiterBI())
                _billInfo.Waiter = bi.Get(x => x.WaiterID == Constants.WAITER);
        }
        public BillItemValue CurrentProduct
        {
            get
            {
                if (_saleForm.BindingSource.Position == -1)
                    return null;
                var item = _bill.ElementAt(_saleForm.BindingSource.Position);
                return item.Key.BillItemType == BillItemType.Product ? item.Value : null;
            }
        }
        public BillItemKey CurrentKot
        {
            get
            {
                if (_saleForm.BindingSource.Position == -1)
                    return null;
                var item = _bill.ElementAt(_saleForm.BindingSource.Position);
                return item.Key.BillItemType == BillItemType.Kot ? item.Key : null;
            }
        }

        public void InitGui(ISaleForm saleForm)
        {
            this._saleForm = saleForm;
            this._saleForm.SetCustomerDisplay(_billInfo.Customer.Name);
            this._saleForm.SetUserName(Session.User.Name);
        }
        public void AddProduct(Product product)
        {
            var newKey = new BillItemKey(product.ProductID, Guid.Empty);

            if (_bill.ContainsKey(newKey))
            {
                _saleForm.BindingSource.CurrencyManager.Position = _bill.IndexOfKey(newKey);
                _bill[newKey].Quantity += 1;
            }
            else
            {
                var billItemValue = new BillItemValue(product);
                var old = _bill.FirstOrDefault(x => x.Key.BillItemType == BillItemType.Product && x.Key.ProductID == newKey.ProductID);
                if (old.Key != null)
                {
                    billItemValue.Discount = old.Value.Discount;
                    billItemValue.Price = old.Value.Price;
                }
                _bill.Add(newKey, billItemValue);
                _saleForm.BindingSource.DataSource = _bill.Values.ToList();
                _saleForm.BindingSource.CurrencyManager.Position = _saleForm.BindingSource.CurrencyManager.Count - 1;

                using (var bi = new ProductGroupModifierBI())
                    if (bi.HasCompulsoryModifier(product.ProductGroup.ProductGroupID))
                    {
                        var item = CurrentProduct;
                        ShowModifiers(item);
                    }
            }
            ShowAmount();
        }
        public void ShowModifiers(BillItemValue item)
        {
            if (item.Printed)
                return;
            using (var frm = new ModifierForm(Cache.ProductGroupModifiers(item.Product.ProductGroup.ProductGroupID), item.Modifiers))
            {
                frm.ShowDialog();
                item.Modifiers = frm.Selection;
            }
            ShowAmount();
        }
        public void SetDiscount()
        {
            if (!Session.IsAllowed("Discount"))
                throw new PermissionException("Not Allowed to give Discount");

            using (var bi = new ProductGroupBI())
            {
                using (var frm = new DiscountForm(bi.GetProductGroupTypes()))
                {
                    if (frm.ShowDialog() == DialogResult.OK)
                    {
                        HashSet<string> outList;
                        var discount = frm.Selection(out outList);
                        discount = discount / 100;
                        if (discount > 1 || discount < 0)
                            throw new ValidationException("Invalid Discount Amount");

                        foreach (var item in _bill.Where(x => x.Key.BillItemType == BillItemType.Product && outList.Contains(x.Value.Product.ProductGroup.GroupType)))
                        {
                            var product = item.Value.Product;
                            var maxDiscount = product.ProductGroup.DiscountLimit;
                            if (discount > item.Value.Product.ProductGroup.DiscountLimit)
                                MessageBox.Show(string.Format("Maximum discount for {0} is {1:P}", product.Name, maxDiscount),
                                                "Excessive Discount", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                            item.Value.Discount = discount;
                        }
                    }
                }
            }
            ShowAmount();
        }
        public void SetQuantity(decimal quantity, bool prompt)
        {
            var item = CurrentProduct;
            if (!Allowed(item))
                return;
            if (item.Printed)
                return;
            if (prompt && !GetInput("Quantity", ref quantity))
                return;
            if (!prompt)
                quantity += item.Quantity;
            if (quantity < 0 && !Session.IsAllowed("Edit Printed Product"))
                return;
            var total = quantity + _bill.Where(x => x.Key.ProductID == item.ProductID && x.Key.BillItemType == BillItemType.Product && x.Value.Printed).Sum(x => x.Value.Quantity);
            if (total < 0)
                quantity -= total;
            item.Quantity = quantity;
            ShowAmount();
        }
        public void SetRate()
        {
            var item = CurrentProduct;
            if (item == null)
                throw new ValidationException("No Product Selected");
            if (!Session.IsAllowed("Change Rate"))
                throw new PermissionException("Rate Change not Allowed");
            var rate = item.Price;
            if (!GetInput("Price", ref rate))
                return;
            if (rate == 0 && !Session.IsAllowed("NC Product"))
                throw new PermissionException("NC of Product is not Allowed");
            foreach (var sub in _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.ProductID == item.ProductID))
                sub.Value.Price = rate;

            ShowAmount();
        }
        public void ShowCustomers(bool reset)
        {
            if (!reset && ((_billInfo.Customer == null) || _billInfo.Customer.CustomerID == Constants.CASH_CUSTOMER))
            {
                using (var selectCustomer = new SelectCustomer(CustomerBI.StaticList, true))
                {
                    selectCustomer.CustomerEvent += selectCustomer_customerEvent;
                    selectCustomer.ShowDialog();
                    if (selectCustomer.SelectedItem != null)
                    {
                        _billInfo.Customer = selectCustomer.SelectedItem;
                    }
                    else
                    {
                        using (var bi = new CustomerBI())
                            _billInfo.Customer = bi.Get(x => x.CustomerID == Constants.CASH_CUSTOMER);
                    }
                }
            }
            else
            {
                using (var bi = new CustomerBI())
                    _billInfo.Customer = bi.Get(x => x.CustomerID == Constants.CASH_CUSTOMER);
            }
            _saleForm.SetCustomerDisplay(_billInfo.Customer.Name);
        }
        private Customer selectCustomer_customerEvent(object sender, CustomerEventArgs e)
        {
            using (var form = new CustomersForm(e.CustomerID, e.Phone))
            {
                form.ShowDialog();
                return form.Customer;
            }
        }
        public void ShowWaiters(bool reset)
        {
            if (reset)
            {
                using (var bi = new WaiterBI())
                    _billInfo.Waiter = bi.Get(x => x.WaiterID == Constants.WAITER);
            }
            else
            {
                using (var selectWaiter = new SelectWaiter(WaiterBI.StaticList, true))
                {
                    selectWaiter.WaiterEvent += selectWaiter_waiterEvent;
                    selectWaiter.ShowDialog();
                    if (selectWaiter.SelectedItem != null)
                    {
                        _billInfo.Waiter = selectWaiter.SelectedItem;
                    }
                    else
                    {
                        using (var bi = new WaiterBI())
                            _billInfo.Waiter = bi.Get(x => x.WaiterID == Constants.WAITER);
                    }
                }
            }
            _saleForm.SetWaiterDisplay(_billInfo.Waiter.Name);
        }
        private Waiter selectWaiter_waiterEvent(object sender, SelectorEventArgs<Waiter> e)
        {
            var waiter = e.Item;
            //if (!Thread.CurrentPrincipal.IsInRole("Waiter/Master"))
            //    return waiter;

            using (var bi = new WaiterBI())
            {
                switch (e.Action)
                {
                    case SelectorAction.Insert: // Add
                        bi.Insert(waiter);
                        bi.SaveChanges();
                        e.Handled = true;
                        return waiter;
                    case SelectorAction.Update: // Edit
                        bi.Update(waiter);
                        bi.SaveChanges();
                        e.Handled = true;
                        return waiter;
                    case SelectorAction.Delete: // Delete
                        bi.Delete(x => x.WaiterID == waiter.WaiterID);
                        bi.SaveChanges();
                        e.Handled = true;
                        return bi.Get(x => x.WaiterID == Constants.WAITER);
                    default:
                        e.Handled = true;
                        return bi.Get(x => x.WaiterID == Constants.WAITER);
                }
            }
        }
        private void ShowAmount()
        {
            var taxAmount = _bill.Values.Sum(b => b.ServiceTaxAmount + b.VatAmount);
            var discountAmount = _bill.Values.Sum(b => b.DiscountAmount);
            var grossAmount = _bill.Values.Sum(b => b.GrossAmount);
            var valueAmount = _bill.Values.Sum(b => b.Value);
            var serviceChargeAmount = _bill.Values.Sum(b => b.ServiceChargeAmount);
            _saleForm.ShowAmount(discountAmount, grossAmount, serviceChargeAmount, taxAmount, valueAmount,
                                _bill.Values.ToList());
        }
        private static bool Allowed(BillItemValue item)
        {
            return item != null;
        }
        private static void IsPrintedOrVoid(Voucher voucher, out bool isPrinted, out bool isVoid)
        {
            using (var bi = new VoucherBI())
            {
                var dbVoucher = bi.Get(x => x.VoucherID == voucher.VoucherID);
                isPrinted = dbVoucher.Printed;
                isVoid = dbVoucher.Void;
            }
        }
        private static bool IsPrintedOrVoid(Voucher voucher)
        {
            using (var bi = new VoucherBI())
            {
                var dbVoucher = bi.Get(x => x.VoucherID == voucher.VoucherID);
                return dbVoucher.Printed || dbVoucher.Void;
            }
        }
        private static bool IsPrintedOrVoid(Guid voucherID)
        {
            using (var bi = new VoucherBI())
            {
                var dbVoucher = bi.Get(x => x.VoucherID == voucherID);
                return dbVoucher.Printed || dbVoucher.Void;
            }
        }
        private bool? IsReprint(out decimal amount)
        {
            amount = 0;
            if (_billInfo.VoucherID == Guid.Empty)
                return false;

            bool isPrinted, isVoid;
            IsPrintedOrVoid(_billInfo, out isPrinted, out isVoid);

            if (isVoid)
            {
                MessageBox.Show(string.Format("This Bill is already void.\nReason: {0}", _billInfo.VoidReason), "Bill already Voided", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return null;
            }

            if (isPrinted && (!Session.IsAllowed("Edit Printed Bill")))
                return null;
            amount = _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.KotID != Guid.Empty).Sum(x => x.Value.GrossAmount);

            return isPrinted;
        }
        private void InputBox_Validating(object sender, InputBoxValidatingArgs e)
        {
        }
        private void LoadBill(Guid voucherID)
        {
            ClearBill();
            using (var bi = new VoucherBI())
            {
                _billInfo = bi.Get(x => x.VoucherID == voucherID);
                _bill.Clear();
                _saleForm.ShowInfo(_billInfo);
                _bill.Load(_billInfo);
                var newKotKey = new BillItemKey(Guid.Empty);
                var newKotItem = new BillItemValue();
                _bill.Add(newKotKey, newKotItem);
                ShowAmount();
                _saleForm.FormState = SaleFormState.Billing;
            }
        }
        public void LoadBill(string tableName)
        {
            FoodTable table;
            using (var bi = new FoodTableBI())
                table = bi.Get(x => x.Name == tableName);
            if (table != null && table.VoucherID.HasValue)
            {
                LoadBill(table.VoucherID.Value);
            }
            else
            {
                using (var frm = new PaxForm())
                {
                    frm.ShowDialog();
                    _billInfo.Table = table;
                    _billInfo.Pax = frm.Pax;
                    _saleForm.ShowInfo(_billInfo);
                }
            }
        }

        public void CancelBillChanges()
        {
            if (_bill.Values.Any(i => i.Printed == false) &&
                MessageBox.Show("Abandon Changes?", "Abandon Changes", MessageBoxButtons.YesNo,
                                MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == DialogResult.No)
                return;
            ClearBill();
        }
        public void ClearBill()
        {
            _billInfo = new Voucher(Session.User);
            ShowCustomers(true);
            ShowWaiters(true);
            _bill.Clear();
            var newKotKey = new BillItemKey(Guid.Empty);
            var newKotItem = new BillItemValue();
            _bill.Add(newKotKey, newKotItem);
            _saleForm.ClearBill(_bill.Values.ToList());
        }
        public SaleFormState FormLoad()
        {
            ClearBill();
            if (_editVoucherID.HasValue)
            {
                LoadBill(_editVoucherID.Value);
                return SaleFormState.Billing;
            }
            return SaleFormState.Waiting;
        }
        internal void SettleBill()
        {
            if (_billInfo.VoucherID == Guid.Empty)
                return;
            if (!_billInfo.Printed)
                return;
            if (!Session.IsAllowed("Settle Bill"))
                return;
            IDictionary<SettleOption, decimal> options;
            var amount = -1 * _billInfo.Kots.Sum(x => x.Inventories.Sum(y => y.Amount));
            using (var frm = new SettleChoicesForm(Math.Round(amount) * -1, _billInfo.VoucherType))
            {
                frm.ShowDialog();
                options = frm.OptionsChosen;
            }
            if (options.Count == 0)
                return;
            using (var bi = new VoucherSettlementBI())
            {
                bi.SettleVoucher(Session.User, _billInfo.VoucherID, options);
                bi.SaveChanges();
            }
            ClearBill();
        }

        #region Move Table(s) / Kot(s)
        private static FoodTable GetTableForMove(bool allowMerge)
        {
            using (var bi = new FoodTableBI())
            {
                using (var frm = new MoveTableForm(bi.List(x => x.IsActive), allowMerge))
                {
                    frm.ShowDialog();
                    if (frm.Selection != null)
                        return frm.Selection;
                }
                return null;
            }
        }
        internal void MoveKot()
        {
            if (_billInfo.VoucherID == Guid.Empty)
                return;
            if (IsPrintedOrVoid(_billInfo))
                return;
            var kot = CurrentKot;
            if (kot == null)
                return;
            var table = GetTableForMove(true);
            if (table == null)
                return;
            if (table.FoodTableID == _billInfo.Table.FoodTableID)
                return;
            if (table.VoucherID != null)
                if (IsPrintedOrVoid(table.VoucherID.Value))
                    return;
            var kotCount = _bill.Keys.Count(x => x.BillItemType == BillItemType.Kot && x.KotID != Guid.Empty);
            var voucherID = Guid.Empty;
            if (table.VoucherID == null && kotCount > 1)
                //Move Kot
                voucherID = MoveKot(kot, table);
            else if (table.VoucherID != null && kotCount > 1)
                //Merge Kot
                voucherID = MergeKot(kot, table);
            else if (table.VoucherID == null && kotCount == 1)
                //Move Table
                voucherID = MoveTable(table.FoodTableID);
            else if (table.VoucherID != null && kotCount == 1)
                //Merge Table
                voucherID = MergeTable(table);
            if (voucherID != Guid.Empty)
                LoadBill(voucherID);
        }
        internal void MoveTable()
        {
            if (_billInfo.VoucherID == Guid.Empty)
                return;

            var allowMerge = !IsPrintedOrVoid(_billInfo);

            var table = GetTableForMove(allowMerge);
            if (table == null)
                return;
            if (table.FoodTableID == _billInfo.Table.FoodTableID)
                return;
            if (table.VoucherID.HasValue)
                if (IsPrintedOrVoid(table.VoucherID.Value))
                    return;

            LoadBill(table.VoucherID.HasValue ? MergeTable(table) : MoveTable(table.FoodTableID));
        }
        private Guid MoveKot(BillItemKey kot, FoodTable table)
        {
            if (!Session.IsAllowed("Move Kot to New Table"))
                return Guid.Empty;
            using (var bi = new VoucherBI())
            {
                var newVoucherID = bi.MoveKot(kot.KotID, table.FoodTableID);
                bi.SaveChanges();
                return newVoucherID;
            }
        }
        private static Guid MergeKot(BillItemKey kot, FoodTable table)
        {
            if (!Session.IsAllowed("Merge Kots"))
                return Guid.Empty;
            using (var bi = new VoucherBI())
            {
                var newVoucherID = bi.MergeKot(kot.KotID, table.Name);
                bi.SaveChanges();
                return newVoucherID;
            }
        }
        private Guid MoveTable(Guid tableID)
        {
            if (!Session.IsAllowed("Move Table"))
                return Guid.Empty;
            using (var bi = new VoucherBI())
            {
                var newVoucherID = bi.Move(_billInfo.Table.FoodTableID, tableID);
                bi.SaveChanges();
                return newVoucherID;
            }
        }
        private Guid MergeTable(FoodTable table)
        {
            if (!Session.IsAllowed("Merge Tables"))
                return Guid.Empty;
            using (var bi = new VoucherBI())
            {
                var newVoucherID = bi.MergeTables(_billInfo.VoucherID, table.Name);
                bi.SaveChanges();
                return newVoucherID;
            }
        }
        #endregion

        #region Save
        public void SaveKot()
        {
            #region Check if Allowed
            if (!Session.IsAllowed("Print Kot"))
                return;
            if (_billInfo.VoucherID != Guid.Empty && IsPrintedOrVoid(_billInfo))
                return;
            if (_bill.Count == 1) //new kot only
                return;
            #endregion

            //Save
            var saved = _billInfo.VoucherID == Guid.Empty ? InsertVoucher(false, !_editVoucherID.HasValue) : UpdateVoucher(false, !_editVoucherID.HasValue);

            //Print
            if ((!_editVoucherID.HasValue || _print) && saved.HasValue)
                Thermal.PrintKot(_billInfo.VoucherID, saved.Value);

            //Cleanup
            if (_editVoucherID.HasValue)
                _saleForm.CloseWindow();
            else
                ClearBill();
        }
        public void SaveBill()
        {
            #region Check if Allowed
            if (!Session.IsAllowed("Print Bill"))
                throw new PermissionException("Printing not allowed");
            if (_bill.Count == 1) //new kot only
                return;
            #endregion

            decimal amount;

            var isReprint = IsReprint(out amount);
            if (!isReprint.HasValue)
                return;
            else if (isReprint.Value)
            {
                try
                {
                    SetDiscount();
                }
                catch (Exception ex)
                {
                    if (!(ex is ValidationException) && !(ex is PermissionException))
                        throw;
                }
                SaveReprintOrDiscountBill(amount);
            }
            else
            {
                try
                {
                    SetDiscount();
                }
                catch (Exception ex)
                {
                    if (!(ex is ValidationException) && !(ex is PermissionException))
                        throw;
                }
                // Ask for VoucherType only for new bill, if none, then cancel
                VoucherType? voucherType;
                using (var frm = new VoucherTypeForm())
                {
                    frm.ShowDialog();
                    voucherType = frm.Selection;
                }
                if (!voucherType.HasValue)
                    return;
                _billInfo.VoucherType = voucherType.Value;
                var saved = _billInfo.VoucherID == Guid.Empty ? InsertVoucher(true, !_editVoucherID.HasValue) : UpdateVoucher(true, !_editVoucherID.HasValue);
            }
            if (!_editVoucherID.HasValue || _print)
                Thermal.PrintBill(_billInfo.VoucherID);
            if (_editVoucherID.HasValue)
                _saleForm.CloseWindow();
            ClearBill();
        }
        public void SplitBill()
        {
            #region Permissions

            bool isPrinted, isVoid;
            IsPrintedOrVoid(_billInfo, out isPrinted, out isVoid);
            if (_billInfo.VoucherID == Guid.Empty || isVoid)
                return; // must be existing non void bill

            if (!Session.IsAllowed("Split Bill"))
                return;
            #endregion

            #region Get Move List
            HashSet<string> splitList = null;
            using (var bi = new ProductGroupBI())
            {
                using (var frm = new DiscountForm(bi.GetProductGroupTypes()))
                    if (frm.ShowDialog() == DialogResult.OK)
                        frm.Selection(out splitList);
            }
            if (splitList == null || splitList.Count == 0)
                return;

            var listFirst = _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.KotID != Guid.Empty && splitList.Contains(x.Value.Product.ProductGroup.GroupType));
            var listSecond = _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.KotID != Guid.Empty && !splitList.Contains(x.Value.Product.ProductGroup.GroupType));

            if (listFirst.Count() == 0 || listSecond.Count() == 0)
                return; // all or none items selected to be moved
            #endregion

            var table = GetTableForMove(false);
            if (table == null)
                return;

            #region new voucherFirst
            var voucherFirst = new Voucher(Session.User)
            {
                Customer = _billInfo.Customer,
                Table = table,
                Waiter = _billInfo.Waiter,
                Printed = isPrinted,
                Void = false,
                Narration = "",
                VoucherType = _billInfo.VoucherType
            };

            var kotFirst = GetKot(listFirst);
            if (kotFirst != null)
                voucherFirst.Kots.Add(kotFirst);
            #endregion

            #region new voucherSecond
            var voucherSecond = new Voucher(Session.User)
            {
                Customer = _billInfo.Customer,
                Table = _billInfo.Table,
                Waiter = _billInfo.Waiter,
                Printed = isPrinted,
                Void = false,
                Narration = "",
                VoucherType = _billInfo.VoucherType
            };

            var kotSecond = GetKot(listSecond);
            if (kotSecond != null)
                voucherSecond.Kots.Add(kotSecond);
            #endregion
            using (var bi = new VoucherBI())
            {
                bi.SplitBill(_billInfo.VoucherID, voucherFirst, voucherSecond);
                bi.SaveChanges();
            }
            if (isPrinted)
            {
                Thermal.PrintBill(voucherFirst.VoucherID);
                Thermal.PrintBill(voucherSecond.VoucherID);
            }
            LoadBill(voucherFirst.VoucherID);
        }
        public void VoidBill()
        {
            #region Check conditions and Permissions
            if (_billInfo.VoucherID == Guid.Empty)
                return;
            //if (!_billInfo.Printed)
            //    return;
            if (_billInfo.Void)
                return;
            if (!Session.IsAllowed("Void Bill"))
                return;
            if (MessageBox.Show("Are you sure you want to void this bill?", "Void Bill", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) != DialogResult.Yes)
                return;
            #endregion

            var voidReason = new SelectVoidReason(GetVoidReason, true);
            voidReason.ShowDialog();
            if (voidReason.SelectedItem != null)
            {
                using (var bi = new VoucherBI())
                {
                    bi.VoidBill(_billInfo.VoucherID, voidReason.SelectedItem.Description, !_editVoucherID.HasValue);
                    bi.SaveChanges();
                }
                ClearBill();
            }
            else
            {
                MessageBox.Show("Please Select a reason if you want to void the bill", "Bill NOT Voided", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
            }
        }
        private static List<StringType> GetVoidReason(Dictionary<string, string> filter)
        {
            var list = new List<StringType>
                           {
                               new StringType("Discount"),
                               new StringType("Printing Fault"),
                               new StringType("Item Changed"),
                               new StringType("Quantity Reduced"),
                               new StringType("Costing Bill for Party"),
                               new StringType("Cashier Mistake"),
                               new StringType("Management Freesale"),
                               new StringType("Other")
                           };
            return list.Where(i => i.Description.ToLower().Contains(filter["Name"].ToLower().Trim())).ToList();
        }
        private void SaveReprintOrDiscountBill(decimal oldAmount)
        {
            var amountChanged = oldAmount != _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.KotID != Guid.Empty).Sum(x => x.Value.GrossAmount);
            var itemsChanged = _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.KotID == Guid.Empty).Count() != 0;
            if (amountChanged || itemsChanged) // Discount or Products changed
            {
                #region new voucherFirst
                var newVoucher = new Voucher(Session.User)
                {
                    Customer = _billInfo.Customer,
                    Table = _billInfo.Table,
                    Waiter = _billInfo.Waiter,
                    Printed = true,
                    Void = false,
                    Narration = "",
                    VoucherType = _billInfo.VoucherType
                };

                var kotNew = GetKot(_bill.Where(x => x.Key.BillItemType == BillItemType.Product));
                if (kotNew != null)
                    newVoucher.Kots.Add(kotNew);
                #endregion

                using (var bi = new VoucherBI())
                {
                    bi.DiscountPrintedBill(_billInfo.VoucherID, newVoucher);
                    bi.SaveChanges();
                }
                LoadBill(newVoucher.VoucherID);
            }
            else
            {
                using (var bi = new ReprintBI())
                {
                    bi.Insert(new Reprint() { User = Session.User, Voucher = _billInfo });
                    bi.SaveChanges();
                }
            }
        }
        private Guid? InsertVoucher(bool finalBill, bool updateTable)
        {
            _billInfo.Printed = finalBill;
            _billInfo.Void = false;
            _billInfo.Narration = "";
            var kot = GetKot(_bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.KotID == Guid.Empty && x.Value.Quantity != 0));
            if (kot == null)
                return null;
            _billInfo.Kots.Add(kot);
            using (var bi = new VoucherBI())
            {
                var kotID = bi.Insert(_billInfo, updateTable);
                bi.SaveChanges();
                return kotID;
            }
        }
        private Guid? UpdateVoucher(bool finalBill, bool updateTable)
        {
            using (var bi = new VoucherBI())
            {
                var voucher = bi.Get(x => x.VoucherID == _billInfo.VoucherID);
                voucher.User = Session.User;
                voucher.Customer = _billInfo.Customer;
                voucher.Waiter = _billInfo.Waiter;
                voucher.Printed = finalBill;
                voucher.VoucherType = _billInfo.VoucherType;
                foreach (var item in _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.KotID != Guid.Empty))
                {
                    var i = voucher.Kots.Single(x => x.KotID == item.Key.KotID).Inventories.Single(x => x.Product.ProductID == item.Key.ProductID);
                    i.Discount = item.Value.Discount;
                    i.Price = item.Value.Price;
                }
                if (!_billInfo.Printed)
                {
                    var kot = GetKot(_bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.KotID == Guid.Empty && x.Value.Quantity != 0));
                    if (kot != null)
                        voucher.Kots.Add(kot);
                }
                var kotID = bi.Update(voucher, updateTable);
                bi.SaveChanges();
                return kotID;
            }
        }
        private static Kot GetKot(IEnumerable<KeyValuePair<BillItemKey, BillItemValue>> list)
        {
            var kot = new Kot();
            foreach (var item in list)
            {
                var oldInv = kot.Inventories.SingleOrDefault(x => x.Product.ProductID == item.Key.ProductID);
                if (oldInv != null)
                {
                    oldInv.Quantity += item.Value.Quantity;
                    if (oldInv.Quantity == 0)
                        kot.Inventories.Remove(oldInv);
                }
                else
                {
                    var inv = new Inventory
                                  {
                                      Product = item.Value.Product,
                                      Quantity = item.Value.Quantity,
                                      Price = item.Value.Price,
                                      FullPrice = item.Value.FullPrice,
                                      Discount = item.Value.Discount,
                                      ServiceCharge = item.Value.ServiceCharge,
                                      IsScTaxable = item.Value.IsScTaxable,
                                      ServiceTaxRate = item.Value.ServiceTaxRate,
                                      VatRate = item.Value.VatRate,
                                      ServiceTax = item.Value.ServiceTax,
                                      Vat = item.Value.Vat
                                  };
                    foreach (var mod in item.Value.Modifiers)
                        inv.InventoryModifier.Add(new InventoryModifier { Modifier = mod });
                    kot.Inventories.Add(inv);
                }
            }

            return kot.Inventories.Count == 0 ? null : kot;
        }
        #endregion

        #region InputBox
        private bool GetInput(string prompt, ref decimal amount)
        {
            var result = InputBox.Show(prompt, amount.ToString(), InputBox_Validating);
            if (!result.OK)
                return false;
            return decimal.TryParse(result.Text, out amount);
        }
        private bool GetInput(string prompt, ref string info)
        {
            var result = InputBox.Show(prompt, info, InputBox_Validating);
            if (!result.OK)
                return false;
            info = result.Text.Trim();
            return !string.IsNullOrEmpty(info);
        }
        #endregion
    }
}