// Copyright (c) 2017- schick Informatik
// Description: Display dialog for customs XML data upload app
//

using bsmd.database.EasyPeasy;
using ENI2.Util;
using Microsoft.Win32;
using System;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Input;
using System.Windows.Media.Imaging;
using System.Xml;
using System.Xml.Serialization;

namespace ENI2.Controls
{
    /// <summary>
    /// Interaction logic for EasyPeasyControl.xaml
    /// </summary>
    public partial class EasyPeasyControl : UserControl
    {

        private ProofRequest _vm;

        #region Construction

        public EasyPeasyControl()
        {
            InitializeComponent();

            this.dataGridGoodsItems.ContextMenu = new ContextMenu();

            MenuItem addItem = new MenuItem();
            addItem.Header = Properties.Resources.textAdd;
            addItem.Icon = new Image { Source = new BitmapImage(new Uri("pack://application:,,,/Resources/add.png")) };
            addItem.Click += AddItem_Click;
            this.dataGridGoodsItems.ContextMenu.Items.Add(addItem);

            MenuItem deleteItem = new MenuItem();
            deleteItem.Header = Properties.Resources.textDelete;
            deleteItem.Icon = new Image { Source = new BitmapImage(new Uri("pack://application:,,,/Resources/delete.png")) };
            deleteItem.Click += DeleteItem_Click;
            this.dataGridGoodsItems.ContextMenu.Items.Add(deleteItem);

            // Add separator and paste option
            this.dataGridGoodsItems.ContextMenu.Items.Add(new Separator());

            MenuItem pasteItem = new MenuItem();
            pasteItem.Header = "Paste";
            pasteItem.Click += (s, e) => HandlePasteOperation();
            this.dataGridGoodsItems.ContextMenu.Items.Add(pasteItem);

            // Add command bindings for proper keyboard handling
            this.dataGridGoodsItems.CommandBindings.Add(new CommandBinding(
                ApplicationCommands.Paste,
                (s, e) => HandlePasteOperation(),
                (s, e) => e.CanExecute = Clipboard.ContainsText()));

        }

        #endregion

        public void SaveState()
        {
            try
            {
                EasyPeasyState.Save(_vm);
            }
            catch { }
        }

        #region context menu event handler

        private void AddItem_Click(object sender, RoutedEventArgs e)
        {
            if (_vm?.ProofInformationT2LT2LF?.GoodsShipmentForT2LT2LF?.GoodsItemsForT2LT2LF == null) return;
            var list = _vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF.GoodsItemsForT2LT2LF;
            int nextItemNo = list.Any() ? list.Max(x => x.GoodsItemNumber) + 1 : 1;
            var item = new GoodsItemForT2LT2LF
            {
                GoodsItemNumber = nextItemNo
            };
            list.Add(item);
        }

        private void DeleteItem_Click(object sender, RoutedEventArgs e)
        {
            foreach(GoodsItemForT2LT2LF item in this.dataGridGoodsItems.SelectedItems.Cast<GoodsItemForT2LT2LF>().ToArray())
            {
                if (_vm?.ProofInformationT2LT2LF?.GoodsShipmentForT2LT2LF?.GoodsItemsForT2LT2LF == null) return;
                var list = _vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF.GoodsItemsForT2LT2LF;
                list.Remove(item);
            }            
        }

        #endregion

        #region button event handler

        private void buttonClear_Click(object sender, RoutedEventArgs e)
        {
            CleanupAutoCalculation();

            this._vm = EasyPeasyState.CreateDefault();            
            if (_vm.ProofInformationT2LT2LF?.GoodsShipmentForT2LT2LF?.GoodsItemsForT2LT2LF == null)            
                _vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF.GoodsItemsForT2LT2LF = new ObservableCollection<GoodsItemForT2LT2LF>();

            _vm.ProofInformationT2LT2LF.DeclarationDate = DateTime.Now; // reset to today
            _vm.ProofInformationT2LT2LF.RequestedValidityOfTheProof.NumberOfDays = 90; // default 90 days

            this.DataContext = this._vm;
            SetupAutoCalculation();
        }

        private void buttonExport_Click(object sender, RoutedEventArgs e)
        {
            var dlg = new SaveFileDialog
            {
                FileName = "proofRequest.xml",
                Filter = "XML file|*.xml",
                OverwritePrompt = true
            };
            if (dlg.ShowDialog() == true)
            {
                try
                {
                    var ser = new XmlSerializer(typeof(ProofRequest));

                    // Namespaces (if needed)
                    // var ns = new XmlSerializerNamespaces();
                    // ns.Add("xsd", "http://www.w3.org/2001/XMLSchema");
                    // ns.Add("xsi", "http://www.w3.org/2001/XMLSchema-instance");

                    var settings = new XmlWriterSettings
                    {
                        Indent = true,
                        OmitXmlDeclaration = true
                    };

                    using (var fs = File.Create(dlg.FileName))
                    using (var xw = XmlWriter.Create(fs, settings))
                    {
                        ser.Serialize(xw, _vm); //, ns);
                    }

                    MessageBox.Show("Exported successfully.", "easy-peasy", MessageBoxButton.OK, MessageBoxImage.Information);
                }
                catch (Exception ex)
                {
                    MessageBox.Show("Export failed:\n" + ex.Message, "easy-peasy", MessageBoxButton.OK, MessageBoxImage.Error);
                }
            }
        }

        private void buttonImport_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Filter = "XML file|*.xml";
            ofd.RestoreDirectory = true;
            ofd.Multiselect = false;

            if (ofd.ShowDialog() == true)
            {
                using (var fs = File.OpenRead(ofd.FileName))
                {
                    CleanupAutoCalculation();
                    var ser = new XmlSerializer(typeof(ProofRequest));
                    _vm = (ProofRequest)ser.Deserialize(fs);
                    // after loading/creating _vm
                    if (_vm.ProofInformationT2LT2LF?.GoodsShipmentForT2LT2LF?.GoodsItemsForT2LT2LF == null)                    
                        _vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF.GoodsItemsForT2LT2LF = new ObservableCollection<GoodsItemForT2LT2LF>();

                    _vm.ProofInformationT2LT2LF.DeclarationDate = DateTime.Now; // reset to today
                    if(_vm.ProofInformationT2LT2LF.RequestedValidityOfTheProof.NumberOfDays == 9)
                        _vm.ProofInformationT2LT2LF.RequestedValidityOfTheProof.NumberOfDays = 90; // default 90 days

                    this.DataContext = _vm;
                    SetupAutoCalculation();
                }
            }
        }

        #endregion

        #region loaded/unloaded event handler

        private void UserControl_Loaded(object sender, RoutedEventArgs e)
        {
            _vm = EasyPeasyState.LoadOrCreate();
            if (_vm.ProofInformationT2LT2LF == null)
                _vm.ProofInformationT2LT2LF = new ProofInformationT2LT2LF();
            if (_vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF == null)
                _vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF = new GoodsShipmentForT2LT2LF
                {
                    LocationOfGoods = new LocationOfGoods(),
                    TransportDocuments = new TransportDocuments()
                };
            _vm.ProofInformationT2LT2LF.DeclarationDate = DateTime.Now; // reset to today
            this.DataContext = _vm;

            SetupAutoCalculation();
        }

        private void UserControl_Unloaded(object sender, RoutedEventArgs e)
        {
            CleanupAutoCalculation();

            try
            {
                EasyPeasyState.Save(_vm);
            }
            catch { }
        }

        #endregion

        #region auto calculation total gross mass

        private void SetupAutoCalculation()
        {
            if (_vm?.ProofInformationT2LT2LF?.GoodsShipmentForT2LT2LF?.GoodsItemsForT2LT2LF != null)
            {
                // Subscribe to collection changes (add/remove items)
                _vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF.GoodsItemsForT2LT2LF.CollectionChanged += GoodsItems_CollectionChanged;

                // Subscribe to DataGrid cell changes
                dataGridGoodsItems.CellEditEnding += DataGridGoodsItems_CellEditEnding;

                // Calculate initial total
                CalculateTotalGrossMass();
            }
        }

        private void CleanupAutoCalculation()
        {
            if (_vm?.ProofInformationT2LT2LF?.GoodsShipmentForT2LT2LF?.GoodsItemsForT2LT2LF != null)
            {
                // Unsubscribe from collection changes
                _vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF.GoodsItemsForT2LT2LF.CollectionChanged -= GoodsItems_CollectionChanged;
                dataGridGoodsItems.CellEditEnding -= DataGridGoodsItems_CellEditEnding;
            }
        }

        private void DataGridGoodsItems_CellEditEnding(object sender, DataGridCellEditEndingEventArgs e)
        {
            // Check if the edited column is GrossMass
            if (e.Column.Header.ToString() == "Gross")
            {
                // Delay calculation to allow the binding to update
                Dispatcher.BeginInvoke(new Action(() => {
                    CalculateTotalGrossMass();
                }), System.Windows.Threading.DispatcherPriority.Background);
            }
        }

        private void GoodsItems_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {            
            // Recalculate total after any collection change
            CalculateTotalGrossMass();
        }

        private void CalculateTotalGrossMass()
        {
            if (_vm?.ProofInformationT2LT2LF?.GoodsShipmentForT2LT2LF?.GoodsItemsForT2LT2LF != null)
            {
                var total = _vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF.GoodsItemsForT2LT2LF
                    .Sum(item => item.GoodsMeasure?.GrossMass ?? 0m);

                _vm.ProofInformationT2LT2LF.TotalGrossMassKg = total;

                // Force UI update by refreshing the binding
                var binding = BindingOperations.GetBindingExpression(
                    FindTotalGrossMassTextBox(), TextBox.TextProperty);
                binding?.UpdateTarget();
            }
        }

        // Simple property changed notification helper
        public event PropertyChangedEventHandler PropertyChanged;
        protected virtual void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

        private TextBox FindTotalGrossMassTextBox()
        {
            // Find the TextBox that displays TotalGrossMassKg
            return this.FindName("textBoxTotalGrossMass") as TextBox ??
                   this.GetTemplateChild("textBoxTotalGrossMass") as TextBox;
        }

        #endregion

        #region cut & paste logic

        private void HandlePasteOperation()
        {
            if (Clipboard.ContainsText())
            {
                var text = Clipboard.GetText();
                if (!TryPaste_EspHsPkgsGross(text))
                    PasteGoodsItems(text);
            }
        }

        private void DataGrid_PreviewKeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.V && (Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control)
            {
                if (Clipboard.ContainsText())
                {
                    var text = Clipboard.GetText();

                    if(!TryPaste_EspHsPkgsGross(text))
                        PasteGoodsItems(text);
                    e.Handled = true;
                }
            }
        }

        private void PasteGoodsItems(string text)
        {
            if (_vm?.ProofInformationT2LT2LF?.GoodsShipmentForT2LT2LF == null) return;

            var lines = text.Replace("\r\n", "\n").Replace('\r', '\n')
                            .Split(new[] { '\n' }, StringSplitOptions.RemoveEmptyEntries);

            foreach (var line in lines)
            {
                // Split by tab first; if only one column, try CSV
                var cells = line.Split('\t');
                if (cells.Length == 1) cells = SplitCsv(line);

                // Expected order: HS, Item#, Description, Gross, Net, Pkgs, Type, Marks
                var item = new GoodsItemForT2LT2LF();

                if (cells.Length > 0) item.Commodity.HarmonizedSystemSubHeadingCode = cells[0].Trim();
                if (cells.Length > 1 && int.TryParse(cells[1], out var n)) item.GoodsItemNumber = n;
                if (cells.Length > 2) item.DescriptionOfGoods = cells[2].Trim();
                if (cells.Length > 3 && decimal.TryParse(cells[3], out var gross)) item.GoodsMeasure.GrossMass = gross;
                if (cells.Length > 4 && decimal.TryParse(cells[4], out var net)) item.GoodsMeasure.NetMass = net;
                if (cells.Length > 5 && int.TryParse(cells[5], out var pkgs)) item.Packaging.NumberOfPackages = pkgs;
                if (cells.Length > 6) item.Packaging.TypeOfPackages = cells[6].Trim();
                if (cells.Length > 7) item.Packaging.ShippingMarks = cells[7].Trim();                

                _vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF.GoodsItemsForT2LT2LF.Add(item);
            }
        }

        // Very small CSV splitter (handles quotes)
        private static string[] SplitCsv(string line)
        {
            var res = new System.Collections.Generic.List<string>();
            var sb = new StringBuilder();
            bool inQuotes = false;
            for (int i = 0; i < line.Length; i++)
            {
                char c = line[i];
                if (c == '\"')
                {
                    if (inQuotes && i + 1 < line.Length && line[i + 1] == '\"')
                    { sb.Append('\"'); i++; }
                    else { inQuotes = !inQuotes; }
                }
                else if (c == ',' && !inQuotes)
                { res.Add(sb.ToString()); sb.Clear(); }
                else { sb.Append(c); }
            }
            res.Add(sb.ToString());
            return res.ToArray();
        }

        private bool TryPaste_EspHsPkgsGross(string text)
        {
            if (_vm?.ProofInformationT2LT2LF?.GoodsShipmentForT2LT2LF == null) return false;

            // Normalize and split lines
            var lines = text.Replace("\r\n", "\n").Replace('\r', '\n')
                            .Split(new[] { '\n' }, StringSplitOptions.RemoveEmptyEntries);
            if (lines.Length == 0) return false;

            // Determine next item number
            var list = _vm.ProofInformationT2LT2LF.GoodsShipmentForT2LT2LF.GoodsItemsForT2LT2LF;
            int nextItemNo = list.Any() ? list.Max(x => x.GoodsItemNumber) + 1 : 1;

            bool anyAdded = false;
            bool countrySeen = false;

            foreach (var raw in lines)
            {
                var line = raw; // do not Trim() entirely; keep leading tab as empty first cell
                var cells = line.Split('\t'); // keeps empty entries

                // Expected:
                //  - 4 cells: [ESP or ""], [HS], [Pkgs], [Gross]
                //  - 3 cells: [HS], [Pkgs], [Gross]
                string hs = null, pkgs = null, gross = null;

                if (cells.Length >= 4)
                {
                    string c0 = cells[0]?.Trim();
                    // Optionally capture the first token like "ESP" (country tag),
                    // only once and only if alphabetic (won't throw if numeric)
                    if (!countrySeen && !string.IsNullOrWhiteSpace(c0) && c0.All(ch => char.IsLetter(ch)))
                    {
                        // If you decide later this should set a field, uncomment:
                        // if (string.IsNullOrWhiteSpace(_vm.Country)) _vm.Country = c0;
                        countrySeen = true;
                    }

                    hs = (cells.Length > 1 ? cells[1] : null);
                    pkgs = (cells.Length > 2 ? cells[2] : null);
                    gross = (cells.Length > 3 ? cells[3] : null);
                }
                else if (cells.Length == 3)
                {
                    hs = cells[0];
                    pkgs = cells[1];
                    gross = cells[2];
                }
                else
                {
                    // Not enough data for this format; skip the row
                    continue;
                }

                if (string.IsNullOrWhiteSpace(hs)) continue;

                var item = new GoodsItemForT2LT2LF
                {
                    GoodsItemNumber = nextItemNo++,
                    DescriptionOfGoods = "" // per spec
                };
                item.Commodity.HarmonizedSystemSubHeadingCode = hs.Trim();

                if (TryParseIntFlexible(pkgs, out var pk))
                    item.Packaging.NumberOfPackages = pk;

                if (TryParseDecimalFlexible(gross, out var g))
                {
                    item.GoodsMeasure.GrossMass = g;
                    var net = g - 1m;
                    if (net < 0m) net = 0m;
                    item.GoodsMeasure.NetMass = net;
                }

                item.DescriptionOfGoods = "Brand New Vehicles"; // per spec
                item.Packaging.TypeOfPackages = "UN"; // per spec
                item.Packaging.ShippingMarks = "-"; // per spec                

                list.Add(item);
                anyAdded = true;
            }

            return anyAdded;
        }



        #endregion

        #region static utils

        // this will go somewhere else later

        // Try parse decimal with current culture, invariant, and comma/dot flip
        private static bool TryParseDecimalFlexible(string s, out decimal value)
        {
            s = (s ?? "").Trim();
            // 1) current culture
            if (decimal.TryParse(s, NumberStyles.Number, CultureInfo.CurrentCulture, out value)) return true;
            // 2) invariant
            if (decimal.TryParse(s, NumberStyles.Number, CultureInfo.InvariantCulture, out value)) return true;
            // 3) flip comma/dot and retry (helps when clipboard mixes locales)
            string flipped = s.Contains(",") ? s.Replace(",", ".") : s.Replace(".", ",");
            if (decimal.TryParse(flipped, NumberStyles.Number, CultureInfo.CurrentCulture, out value)) return true;
            if (decimal.TryParse(flipped, NumberStyles.Number, CultureInfo.InvariantCulture, out value)) return true;
            value = 0m;
            return false;
        }

        private static bool TryParseIntFlexible(string s, out int value)
        {
            s = (s ?? "").Trim();
            // Extract leading integer if something like "12 pcs"
            var digits = new string(s.TakeWhile(ch => char.IsDigit(ch) || ch == '-' || ch == '+').ToArray());
            if (string.IsNullOrEmpty(digits)) digits = s;
            return int.TryParse(digits, NumberStyles.Integer, CultureInfo.CurrentCulture, out value)
                || int.TryParse(digits, NumberStyles.Integer, CultureInfo.InvariantCulture, out value);
        }

        #endregion

    }

}