using System;
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.PointOfSale.Sales;
using Tanshu.Accounts.Print;
using Tanshu.Accounts.Repository;
using Tanshu.Common;

namespace Tanshu.Accounts.PointOfSale
{
    public class BillController
    {
        private readonly OrderedDictionary<BillItemKey, BillItemValue> _bill;

        private Voucher _billInfo;
        private Customer _customer;

        private int? _editVoucherID;
        private readonly bool _print;

        private ISaleForm _saleForm;

        public BillController(int? editVoucherID, bool print)
        {
            this._editVoucherID = editVoucherID;
            _print = print;
            _bill = new OrderedDictionary<BillItemKey, BillItemValue>();
            using (var bi = new CustomerBI(false))
                _customer = bi.Get(x => x.CustomerID == 1);
        }

        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(_customer.Name);
            this._saleForm.SetUserName(Session.User.Name);
        }

        private void InitComponents()
        {
            InitModel();
            InitView();
        }

        private void InitView()
        {
            throw new NotImplementedException();
        }

        private void InitModel()
        {
            throw new NotImplementedException();
        }

        public void AddProductToGrid(Product product)
        {
            AddProduct(product);
            using (var bi = new ProductGroupModifierBI(false))
                if (bi.HasCompulsoryModifier(product.ProductGroup.ProductGroupID))
                {
                    var item = CurrentProduct;
                    ShowModifiers(product.ProductGroup.ProductGroupID, item);
                }
            ShowAmount();
        }

        private void AddProduct(Product product)
        {
            var newKey = new BillItemKey(product.ProductID, 0);

            if (_bill.ContainsKey(newKey))
            {
                _saleForm.BindingSource.CurrencyManager.Position = _bill.IndexOfKey(newKey);
                _bill[newKey].Quantity += 1;
            }
            else
            {
                var billItemValue = new BillItemValue(product)
                {
                    ProductID = product.ProductID,
                    Name = product.Units == string.Empty ? product.Name : product.Name + " (" + product.Units + ")",
                    Price = product.SalePrice,
                    Tax = product.Tax.Rate,
                    ServiceCharge = product.ServiceCharge,
                    Discount = 0,
                    Printed = false,
                    Quantity = 1,
                };

                var old = _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.ProductID == newKey.ProductID).FirstOrDefault();
                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;
            }
        }


        public void ShowModifiers(int productGroupID, BillItemValue item)
        {
            if (item.Printed)
                return;
            using (var bi = new ProductGroupModifierBI(false))
            {
                using (var frm = new ModifierForm(bi.List(productGroupID), item.Modifiers))
                {
                    frm.ShowDialog();
                    item.Modifiers = frm.Selection;
                }
            }
            ShowAmount();
        }

        public void ShowDiscount()
        {
            if (!Session.IsAllowed(RoleConstants.DISCOUNT))
                return;

            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)
                            return;

                        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 ShowCustomerList(bool reset)
        {
            if ((_customer.CustomerID == 1) && (!reset))
            {
                using (var selectCustomer = new SelectCustomer(CustomerBI.List, true))
                {
                    selectCustomer.customerEvent += selectCustomer_customerEvent;
                    selectCustomer.ShowDialog();
                    if (selectCustomer.SelectedItem != null)
                    {
                        _customer = selectCustomer.SelectedItem;
                        _saleForm.SetCustomerDisplay(_customer.Name);
                    }
                    else
                    {
                        using (var bi = new CustomerBI(false))
                            _customer = bi.Get(x => x.CustomerID == 1);
                    }
                }
            }
            else
            {
                using (var bi = new CustomerBI(false))
                    _customer = bi.Get(x => x.CustomerID == 1);
                _saleForm.SetCustomerDisplay(_customer.Name);
            }
        }

        public void VoidBill()
        {
            if (_billInfo == null)
                return;
            if (!_billInfo.Printed)
                return;
            if (!Session.IsAllowed(RoleConstants.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;
            var voidReason = new SelectVoidReason(GetVoidReason, true);
            voidReason.ShowDialog();
            if (voidReason.SelectedItem != null)
            {
                using (var session = SessionManager.Session)
                {
                    using (var trans = session.BeginTransaction())
                    {
                        using (var bi = new VoucherBI(session, false))
                            bi.VoidBill(_billInfo.VoucherID, voidReason.SelectedItem.Description);
                        using (var ft = new FoodTableBI(session, false))
                            ft.UpdateStatus(_billInfo);
                        trans.Commit();
                    }
                }
                ClearBill();
            }
            else
            {
                MessageBox.Show("Please Select a reason if you want to void the bill", "Bill NOT Voided",
                                MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
            }
        }

        private Customer selectCustomer_customerEvent(object sender, CustomerEventArgs e)
        {
            using (var form = new CustomersForm(e.CustomerID, e.Phone))
            {
                form.ShowDialog();
                return form.Customer;
            }
        }

        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 ShowAmount()
        {
            //saleForm.BindingSource.CurrencyManager.Position = 1;

            var taxAmount = _bill.Values.Sum(b => b.TaxAmount);
            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);
            //bill.Values.ToList();
            _saleForm.ShowAmount(discountAmount, grossAmount, serviceChargeAmount, taxAmount, valueAmount,
                                _bill.Values.ToList());
        }

        public void ProductRemove()
        {
            var item = CurrentProduct;
            if (!Allowed(item))
                return;
            if (item.Printed)
                return;
            _bill.Remove(new BillItemKey(item.ProductID, 0));
            _bill.ReCompact();
            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(RoleConstants.EDIT_PRINTED_PRODUCT))
                return;
            var total = quantity + _bill.Where(x => x.Key.ProductID == item.ProductID && x.Key.BillItemType == BillItemType.Product).Sum(x => x.Value.Quantity);
            if (total < 0)
                quantity -= total;
            item.Quantity = quantity;
            ShowAmount();
        }

        public void ChangeRate()
        {
            var item = CurrentProduct;
            if (!Allowed(item, RoleConstants.CHANGE_RATE))
                return;
            var rate = item.Price;
            if (!GetInput("Price", ref rate))
                return;
            if (rate == 0 && !Session.IsAllowed(RoleConstants.ZERO_RATE))
                return;
            foreach (var sub in _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.ProductID == item.ProductID))
                sub.Value.Price = rate;

            ShowAmount();
        }

        private bool Allowed(BillItemValue item, RoleConstants role)
        {
            if (item == null)
                return false;
            return Session.IsAllowed(role);
        }

        private bool Allowed(BillItemValue item)
        {
            return item != null;
        }

        private void InputBox_Validating(object sender, InputBoxValidatingArgs e)
        {
        }

        private void LoadBill(int voucherID)
        {
            ClearBill();
            _bill.Clear();
            _billInfo = null;
            using (var bi = new VoucherBI(false))
                _billInfo = bi.Get(voucherID);

            _customer = _billInfo.Customer;
            _saleForm.ShowInfo(_billInfo.BillID, _billInfo.KotID, _billInfo.CreationDate, _billInfo.Date.Value,
                              _billInfo.LastEditDate, _customer.Name, _billInfo.TableID, _billInfo.Waiter.WaiterID,
                              _billInfo.Waiter.Name);

            foreach (var kot in _billInfo.Kots)
            {
                var kotKey = new BillItemKey(kot.KotID);
                var kotItem = new BillItemValue(null)
                                  {
                                      ProductID = kot.KotID,
                                      Discount = 0,
                                      Name = string.Format("Kot: {0} / {1:dd-MMM HH:mm} ({2})", kot.Code, kot.Date, kot.User.Name),
                                      Price = 0,
                                      Printed = true,
                                      Quantity = 0,
                                      Tax = -1,
                                      ServiceCharge = 0,
                                  };
                _bill.Add(kotKey, kotItem);
                foreach (var inv in kot.Inventories)
                {
                    var key = new BillItemKey(inv.Product.ProductID, kot.KotID);
                    var item = new BillItemValue(inv.Product)
                                   {
                                       ProductID = inv.Product.ProductID,
                                       Discount = inv.Discount,
                                       Name =
                                           inv.Product.Units == string.Empty
                                               ? inv.Product.Name
                                               : inv.Product.Name + " (" + inv.Product.Units + ")",
                                       Price = inv.Rate,
                                       Printed = true,
                                       Quantity = inv.Quantity,
                                       Tax = inv.Tax,
                                       ServiceCharge = inv.ServiceCharge,
                                   };
                    foreach (var mod in inv.InventoryModifier)
                        item.Modifiers.Add(mod.Modifier);
                    _bill.Add(key, item);
                }
            }
            var newKotKey = new BillItemKey(0);
            var newKotItem = new BillItemValue(null)
                                 {
                                     ProductID = 0,
                                     Discount = 0,
                                     Name = "== New Kot ==",
                                     Price = 0,
                                     Printed = true,
                                     Quantity = 0,
                                     Tax = -1,
                                     ServiceCharge = 0,
                                 };
            _bill.Add(newKotKey, newKotItem);
            ShowAmount();
        }

        public void LoadBillFromTable(string tableName)
        {
            if (!string.IsNullOrEmpty(tableName))
            {
                FoodTable table;
                using (var bi = new FoodTableBI())
                    table = bi.Get(x => x.Name == tableName);
                if (table != null && table.VoucherID != 0)
                {
                    LoadBill(table.VoucherID);
                }
            }
            else
            {
                var result = "0";
                if (GetInput("Table Number", ref result))
                    LoadBillFromTable(result);
                else
                    ClearBill();
            }
        }

        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 = null;
            ShowCustomerList(true);
            _bill.Clear();
            var newKotKey = new BillItemKey(0);
            var newKotItem = new BillItemValue(null)
                                 {
                                     ProductID = 0,
                                     Discount = 0,
                                     Name = "== New Kot ==",
                                     Price = 0,
                                     Printed = true,
                                     Quantity = 0,
                                     Tax = -1,
                                     ServiceCharge = 0,
                                 };
            _bill.Add(newKotKey, newKotItem);
            _saleForm.ClearBill(_bill);
        }

        public SaleFormState FormLoad()
        {
            ClearBill();
            if (_editVoucherID.HasValue)
            {
                LoadBill(_editVoucherID.Value);
                return SaleFormState.Billing;
            }
            return SaleFormState.Waiting;
        }

        internal void SettleBill()
        {
            if (_billInfo == null)
                return;
            if (!_billInfo.Printed)
                return;
            if (!Session.IsAllowed(RoleConstants.SETTLE_BILL))
                return;
            IDictionary<SettleOption, decimal> options;
            var amount = (_billInfo.Settlements.Single(x => x.Settled == SettleOption.Amount).Amount +
                          _billInfo.Settlements.Single(x => x.Settled == SettleOption.RoundOff).Amount) * -1;

            using (var frm = new SettleChoicesForm(amount))
            {
                frm.ShowDialog();
                options = frm.OptionsChosen;
            }
            if (options.Count == 0)
                return;
            using (var bi = new VoucherSettlementBI())
                bi.SettleVoucher(Session.User, _billInfo.VoucherID, options);
            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(), allowMerge))
                {
                    frm.ShowDialog();
                    if (frm.Selection != null)
                        return frm.Selection;
                }
                return null;
            }
        }

        internal void MergeKot()
        {
            if (_billInfo == null)
                return;
            using (var bi = new VoucherBI(false))
                if (bi.IsVoucherPrinted(_billInfo.VoucherID) && !Session.IsAllowed(RoleConstants.EDIT_PRINTED_BILL))
                    return;
            var kot = CurrentKot;
            if (kot == null)
                return;
            var table = GetTableForMove(true);
            if (table == null)
                return;
            var kotCount = _bill.Keys.Count(x => x.BillItemType == BillItemType.Kot && x.KotID != 0);
            var voucherID = 0;
            if (table.VoucherID == 0 && kotCount > 1)
                //Move Kot
                voucherID = MoveKot(kot, table);
            else if (table.VoucherID == 0 && kotCount == 1)
                //Move Table
                voucherID = MoveTable(table);
            else if (table.VoucherID != 0 && kotCount > 1)
                //Merge Kot
                voucherID = MergeKot(kot, table);
            else if (table.VoucherID != 0 && kotCount == 1)
                //Merge Table
                voucherID = MergeTable(table);
            if (voucherID != 0)
                LoadBill(voucherID);
        }
        internal void MoveTable()
        {
            if (_billInfo == null)
                return;
            using (var bi = new VoucherBI(false))
                if (bi.IsVoucherPrinted(_billInfo.VoucherID) && !Session.IsAllowed(RoleConstants.EDIT_PRINTED_BILL))
                    return;
            var table = GetTableForMove(true);
            if (table == null)
                return;
            LoadBill(table.VoucherID == 0 ? MoveTable(table) : MergeTable(table));
        }

        private int MoveKot(BillItemKey kot, FoodTable table)
        {
            if (!Session.IsAllowed(RoleConstants.MOVE_KOT))
                return 0;
            var voucher = new Voucher
                              {
                                  Customer = _billInfo.Customer,
                                  TableID = table.Name,
                                  Waiter = _billInfo.Waiter,
                                  Printed = false,
                                  Void = false,
                                  Date = DateTime.Now,
                                  Narration = "",
                                  User = Session.User
                              };

            using (var session = SessionManager.Session)
            {
                using (var trans = session.BeginTransaction())
                {
                    using (var bi = new VoucherBI(session, false))
                    {
                        bi.Insert(voucher);
                        using (var ft = new FoodTableBI(session, false))
                            ft.UpdateStatus(voucher);
                        var voucherId = bi.MergeKot(kot.KotID, voucher);
                        trans.Commit();
                        return voucherId;
                    }
                }
            }
        }

        private static int MergeKot(BillItemKey kot, FoodTable table)
        {
            if (!Session.IsAllowed(RoleConstants.MERGE_KOT))
                return 0;
            using (var bi = new VoucherBI())
                return bi.MergeKot(kot.KotID, table);
        }
        private int MoveTable(FoodTable table)
        {
            if (!Session.IsAllowed(RoleConstants.MOVE_TABLE))
                return 0;
            using (var ft = new FoodTableBI())
                return ft.Move(_billInfo.TableID, table);
        }
        private int MergeTable(FoodTable table)
        {
            if (!Session.IsAllowed(RoleConstants.MERGE_TABLE))
                return 0;
            var kots = _bill.Keys.Where(x => x.BillItemType == BillItemType.Kot && x.KotID != 0);
            foreach (var item in kots)
                MergeKot(item, table);
            using (var bi = new VoucherBI())
                bi.Delete(_billInfo.VoucherID);
            return table.VoucherID;
        }
        #endregion
        #region Save

        public void SaveBill(int waiterID, string tableID)
        {
            if (!Session.IsAllowed(RoleConstants.PRINT_BILL))
                return;
            using (var bi = new VoucherBI(false))
                if ((_billInfo != null) && (bi.IsVoucherPrinted(_billInfo.VoucherID)) && (!Session.IsAllowed(RoleConstants.EDIT_PRINTED_BILL)))
                    return;
            if (_bill.Count == 1) //new kot only
                return;
            ShowDiscount();
            var saved = _billInfo == null ? InsertVoucher(true, waiterID, tableID, !_editVoucherID.HasValue) : UpdateVoucher(true, waiterID, tableID, !_editVoucherID.HasValue);

            if (!_editVoucherID.HasValue || _print)
                Thermal.PrintBill(_billInfo.VoucherID);
            if (_editVoucherID.HasValue)
                _saleForm.CloseWindow();
            ClearBill();
        }

        public void SaveKot(int waiterID, string tableID)
        {
            if (!Session.IsAllowed(RoleConstants.PRINT_KOT))
                return;
            using (var bi = new VoucherBI(false))
                if ((_billInfo != null) && (bi.IsVoucherPrinted(_billInfo.VoucherID)) && (!Session.IsAllowed(RoleConstants.EDIT_PRINTED_BILL)))
                    return;
            if (_bill.Count == 1) //new kot only
                return;
            var saved = _billInfo == null ? InsertVoucher(false, waiterID, tableID, !_editVoucherID.HasValue) : UpdateVoucher(false, waiterID, tableID, !_editVoucherID.HasValue);

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

            if (_editVoucherID.HasValue)
                _saleForm.CloseWindow();
            ClearBill();
        }

        private int? InsertVoucher(bool finalBill, int waiterID, string tableID, bool updateTable)
        {
            if (_billInfo != null)
            {
                MessageBox.Show("Error in InsertVoucher, there is a previous sale in memory", "Error");
                return null;
            }
            _billInfo = new Voucher
                           {
                               Customer = _customer,
                               //Paid = finalBill,
                               TableID = tableID,
                               Waiter = WaiterBI.GetWaiter(waiterID),
                               Printed = finalBill,
                               Void = false,
                               Date = DateTime.Now,
                               Narration = "",
                               User = Session.User
                           };
            UpdateKots();
            var kot = GetKotForBill();
            if (kot != null)
                _billInfo.Kots.Add(kot);
            using (var session = SessionManager.Session)
            {
                using (var trans = session.BeginTransaction())
                {
                    int? kotID;
                    using (var bi = new VoucherBI(session, false))
                        kotID = bi.Insert(_billInfo);
                    if (updateTable)
                        using (var ft = new FoodTableBI(session, false))
                            ft.UpdateStatus(_billInfo);
                    trans.Commit();
                    return kotID;
                }
            }
        }

        private int? UpdateVoucher(bool finalBill, int waiterID, string tableID, bool updateTable)
        {
            _billInfo.User = Session.User;
            _billInfo.Customer = _customer;
            if (!_billInfo.Printed && finalBill)
                _billInfo.Date = null;
            _billInfo.Printed = _billInfo.Printed || finalBill;
            _billInfo.TableID = tableID;
            _billInfo.Waiter = WaiterBI.GetWaiter(waiterID);
            UpdateKots();
            var kot = GetKotForBill();
            if (kot != null)
                _billInfo.Kots.Add(kot);
            using (var session = SessionManager.Session)
            {
                using (var trans = session.BeginTransaction())
                {
                    int? kotID;
                    using (var bi = new VoucherBI(session, false))
                        kotID = bi.Update(_billInfo);
                    if (updateTable)
                        using (var ft = new FoodTableBI(session, false))
                            ft.UpdateStatus(_billInfo);
                    trans.Commit();
                    return kotID;
                }
            }
        }

        private void UpdateKots()
        {
            foreach (var item in _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.KotID != 0))
            {
                var i = _billInfo.Kots.Single(x => x.KotID == item.Key.KotID).Inventories.Single(x => x.Product.ProductID == item.Key.ProductID);
                i.Discount = item.Value.Discount;
                i.Rate = item.Value.Price;
            }
        }
        private Kot GetKotForBill()
        {
            var kot = new Kot();
            foreach (var item in _bill.Where(x => x.Key.BillItemType == BillItemType.Product && x.Key.KotID == 0 && x.Value.Quantity != 0))
            {
                var inv = new Inventory
                               {
                                   Product = item.Value.Product,
                                   Quantity = item.Value.Quantity,
                                   Rate = item.Value.Price,
                                   Discount = item.Value.Discount,
                                   ServiceCharge = item.Value.ServiceCharge,
                                   Tax = item.Value.Tax
                               };
                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;
            if (!decimal.TryParse(result.Text, out amount))
                return false;
            return true;
        }
        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();
            if (string.IsNullOrEmpty(info))
                return false;
            return true;
        }

        #endregion
    }
}