prs/prs.desktop/Panels/Stock Forecast/OrderScreen/StockForecastOrderingGrid.cs

using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using InABox.DynamicGrid;
using InABox.Wpf;
using InABox.WPF;
using NPOI.SS.Formula.Functions;
using Syncfusion.Data;
using Syncfusion.Data.Extensions;
using Syncfusion.UI.Xaml.Grid;
using Syncfusion.Windows.Shared;
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using Columns = InABox.Core.Columns;

namespace PRSDesktop;

public class StockForecastOrderData(ProductLink product, ProductStyleLink style, StockDimensions dimensions)
{
    public ProductLink Product { get; set; } = product;

    public ProductStyleLink Style { get; set; } = style;

    public StockDimensions Dimensions { get; set; } = dimensions;

    public double RequiredQuantity { get; set; }

    public class QuantityBreakup(Guid jobID, Guid requiID, string description, double qty)
    {
        public Guid JobID { get; set; } = jobID != Guid.Empty ? jobID : throw new ArgumentException("jobID cannot be Guid.Empty!", "jobID");

        public Guid JobRequiItemID { get; set; } = requiID;

        public string Description { get; set; } = description;

        public double Quantity { get; set; } = qty;
    }
    
    private List<QuantityBreakup> RequiredQuantities { get; set; } = [];

    public List<QuantityBreakup> GetRequiredQuantities() => RequiredQuantities;
    
    public void SetRequiredQuantity(Guid jobid, Guid requiid, string description, double qty)
    {
        RequiredQuantities.Add(new(jobid, requiid,description,qty));
    }
}

public enum StockForecastOrderingType
{
    StockOrder,
    Breakup
}

public class StockForecastOrderingItemQuantity
{
    public event Action? Changed;

    private double _total;
    public double Total
    {
        get => _total;
        set
        {
            _total = value;
            Changed?.Invoke();
        }
    }

    private SupplierProduct? _supplierProduct;
    /// <summary>
    /// Indicates the Supplier Product that has been selected for this cell. This comes from the combobox column.
    /// </summary>
    public SupplierProduct? SupplierProduct
    {
        get => _supplierProduct;
        set
        {
            _supplierProduct = value;
            Changed?.Invoke();
        }
    }

    public void DoChanged()
    {
        Changed?.Invoke();
    }
}

public class StockForecastOrderingItem : BaseObject
{
    [EditorSequence(1)]
    public ProductLink Product { get; set; }

    [EditorSequence(2)]
    public ProductStyleLink Style { get; set; }

    [EditorSequence(3)]
    public StockDimensions Dimensions { get; set; }
    
    public List<StockForecastOrderData.QuantityBreakup> Breakups { get; } = [];
    
    [EditorSequence(5)]
    [DoubleEditor]
    public double RequiredQuantity { get; set; }

    [EditorSequence(6)]
    [EnumLookupEditor(typeof(SupplierProductOrderStrategy))]
    public SupplierProductOrderStrategy OrderStrategy { get; set; }

    public bool CustomStrategy { get; set; } = false;

    public StockForecastOrderingItemQuantity[] Quantities = [];

    public StockForecastOrderingItemQuantity GetQuantity(int i) => Quantities[i];

    public double GetTotalQuantity(StockForecastOrderingType type) => type == StockForecastOrderingType.StockOrder
        ? Quantities.Sum(x => x.Total)
        : Quantities.Sum(x => x.Total);

    public void SetQuantities(StockForecastOrderingItemQuantity[] quantities)
    {
        Quantities = quantities;
    }
}

public class StockForecastOrderingResult(
    SupplierLink supplier,
    List<StockForecastOrderData.QuantityBreakup> breakups,
    StockForecastOrderingItem item,
    double quantity,
    SupplierProduct supplierProduct)
{
    public SupplierLink Supplier { get; set; } = supplier;

    public StockForecastOrderingItem Item { get; set; } = item;

    public SupplierProduct SupplierProduct { get; set; } = supplierProduct;

    public double Quantity { get; set; } = quantity;

    public List<StockForecastOrderData.QuantityBreakup> Breakups { get; set; } = breakups;
}

public enum StockForecastOrderingStrategy
{
    PerProduct,
    Exact,
    RoundUp,
    LowestUnitPrice,
    LowestOverallPrice,
    LowestOverstock
}

public class StockForecastOrderingGrid : DynamicItemsListGrid<StockForecastOrderingItem>, ISpecificGrid
{
    private List<SupplierProduct> SupplierProducts = [];
    private SupplierLink[] Suppliers = [];

    public IList<StockForecastOrderData> OrderData { get; set; }

    public double TotalQuantity => Items.Sum(x => x.GetTotalQuantity(OrderType));

    private DynamicActionColumn[] SupplierProductColumns = [];
    private DynamicActionColumn[] QuantityColumns = [];
    private DynamicActionColumn[] CostColumns = [];

    //private readonly Dictionary<Guid, Job> JobDetails = [];

    private static BitmapImage _warning = PRSDesktop.Resources.warning.AsBitmapImage();

    private StockForecastOrderingType _orderType = StockForecastOrderingType.Breakup;
    public StockForecastOrderingType OrderType
    {
        get => _orderType;
        set
        {
            if(_orderType != value)
            {
                _orderType = value;
                if (OrderData != null)
                {
                    CalculateQuantities(true);
                    UIComponent.UpdateOrderType(OrderType);

                    Refresh(true, true);
                }
            }
        }
    }

    private StockForecastOrderingStrategy orderStrategy;
    public StockForecastOrderingStrategy OrderStrategy
    {
        get => orderStrategy;
        set
        {
            orderStrategy = value;
            if (OrderData != null)
            {
                foreach (var item in Items)
                {
                    item.OrderStrategy = ForecastOrderStrategyToProductOrderStrategy(value, item.Product.OrderStrategy);
                    item.CustomStrategy = false;
                }
                CalculateQuantities(false);
                Refresh(false, true);
            }
        }
    }

    private static SupplierProductOrderStrategy ForecastOrderStrategyToProductOrderStrategy(StockForecastOrderingStrategy strategy, SupplierProductOrderStrategy defaultValue)
    {
        return strategy switch
        {
            StockForecastOrderingStrategy.Exact => SupplierProductOrderStrategy.Exact,
            StockForecastOrderingStrategy.LowestOverallPrice => SupplierProductOrderStrategy
                .LowestOverallPrice,
            StockForecastOrderingStrategy.LowestUnitPrice => SupplierProductOrderStrategy.LowestUnitPrice,
            StockForecastOrderingStrategy.LowestOverstock => SupplierProductOrderStrategy.LowestOverstock,
            StockForecastOrderingStrategy.RoundUp => SupplierProductOrderStrategy.RoundUp,
            StockForecastOrderingStrategy.PerProduct or _ => defaultValue
        };
    }

    public IEnumerable<StockForecastOrderingResult> Results
    {
        get
        {
            for(int i = 0; i < Suppliers.Length; ++i)
            {
                var supplier = Suppliers[i];
                foreach(var item in Items)
                {
                    var qty = item.GetQuantity(i);
                    if (qty.SupplierProduct is null)
                    {
                        continue;
                    }

                    if(qty.Total > 0)
                    {
                        if(OrderType == StockForecastOrderingType.StockOrder && qty.Total > 0)
                        {
                            yield return new(supplier, new List<StockForecastOrderData.QuantityBreakup>() , item, qty.Total, qty.SupplierProduct);
                        }
                        else
                        {
                            yield return new(supplier, item.Breakups, item, qty.Total, qty.SupplierProduct);
                        }
                    }
                }
            }
        }
    }

    public StockForecastOrderingGrid()
    {
        HiddenColumns.Add(x => x.Product.Image.ID);
    }

    public bool Validate()
    {
        if(OrderType == StockForecastOrderingType.Breakup)
        {
            foreach(var item in Items)
            {
                var sum = item.Breakups.Sum(x => x.Quantity);
                if(sum > item.GetTotalQuantity(OrderType))
                {
                    MessageWindow.ShowMessage($"Not enough being ordered for {item.Product.Code}/{item.Style.Code}: requires at least {sum}", "Not enough");
                    return false;
                }
            }
        }
        return true;
    }

    #region UI Component

    private Component? _uiComponent;
    private Component UIComponent
    {
        get
        {
            _uiComponent ??= new Component(this);
            return _uiComponent;
        }
    }
    protected override IDynamicGridUIComponent<StockForecastOrderingItem> CreateUIComponent()
    {
        return UIComponent;
    }
    private class Component : DynamicGridGridUIComponent<StockForecastOrderingItem>
    {
        private StockForecastOrderingGrid Grid;

        public Component(StockForecastOrderingGrid grid)
        {
            Parent = grid;
            Grid = grid;

            UpdateOrderType(grid.OrderType);
        }

        public void UpdateOrderType(StockForecastOrderingType type)
        {
            DataGrid.FrozenColumnCount = type == StockForecastOrderingType.StockOrder ? 8 : 9;
        }

        protected override Brush? GetCellSelectionBackgroundBrush()
        {
            return null;
        }

        protected override Brush? GetCellBackground(CoreRow row, DynamicColumnBase column)
        {
            var item = Grid.LoadItem(row);
            if(column is DynamicActionColumn ac)
            {
                var qIdx = Grid.QuantityColumns.IndexOf(ac);
                var idx = Math.Max(qIdx, Grid.CostColumns.IndexOf(ac));
                if(idx != -1)
                {
                    var supplierProduct = item.GetQuantity(idx).SupplierProduct;
                    if(supplierProduct is null)
                    {
                        return new SolidColorBrush(Colors.Gainsboro);
                    }
                    //if(item.GetTotalQuantity(Grid.OrderType) < item.RequiredQuantity)
                    //{
                    //    return new SolidColorBrush(Colors.LightSalmon) { Opacity = 0.5 };
                    //}
                    //else
                    //{
                    //    return new SolidColorBrush(Colors.LightGreen) { Opacity = 0.5 };
                    //}
                }
            }
            return base.GetCellBackground(row, column);
        }
    }

    #endregion

    private bool _observing = true;
    private void SetObserving(bool observing)
    {
        _observing = observing;
    }
    protected override void Changed()
    {
        if (_observing)
        {
            base.Changed();
        }
    }

    protected override void DoReconfigure(DynamicGridOptions options)
    {
        options.Clear();
        options.FilterRows = true; 
    }

    private bool _loadedData = false;
    private void LoadData()
    {
        var supplierColumns = Columns.None<SupplierProduct>().Add(x => x.ID)
            .Add(x => x.SupplierLink.ID)
            .Add(x => x.Product.ID)
            .Add(x => x.Style.ID)
            .Add(x => x.Style.Code)
            .Add(x => x.ForeignCurrencyPrice)
            .Add(x => x.CostPrice)
            .AddDimensionsColumns(x => x.Dimensions)
            .Add(x => x.SupplierLink.Code);

        SupplierProducts = Client.Query(
            new Filter<SupplierProduct>(x => x.Product.ID).InList(OrderData.Select(x => x.Product.ID).ToArray())
                .And(x => x.SupplierLink.ID).IsNotEqualTo(Guid.Empty),
            supplierColumns,
            new SortOrder<SupplierProduct>(x => x.SupplierLink.Code))
            .ToList<SupplierProduct>();

        Suppliers = SupplierProducts.Select(x => x.SupplierLink).DistinctBy(x => x.ID).ToArray();

        //LoadJobData(OrderData.SelectMany(x => x.GetRequiredQuantities().Keys).Distinct().Where(x => x != Guid.Empty));

        CalculateQuantities(true);

        _loadedData = true;
    }

    private StockForecastOrderingItemQuantity CreateQuantity(int itemIdx)
    {
        var qty = new StockForecastOrderingItemQuantity();
        qty.Changed += () =>
        {
            if (!_observing) return;

            var row = Data.Rows[itemIdx];
            InvalidateRow(row);
            DoChanged();
        };
        return qty;
    }

    private SupplierProduct CalculateSupplierProduct(StockForecastOrderingItem item, int supplierIdx)
    {
        var supplierProduct = SelectSupplierProduct(SupplierProducts.Where(x => x.Product.ID == item.Product.ID && x.Style.ID == item.Style.ID && x.SupplierLink.ID == Suppliers[supplierIdx].ID), item);

        var qty = item.GetQuantity(supplierIdx);
        qty.SupplierProduct = supplierProduct;
        qty.Total = 0;
        return supplierProduct;
    }

    private void CalculateSupplierProduct(StockForecastOrderingItem item)
    {
        var selectedSupplierProducts = new List<SupplierProduct>();
        for(int i = 0; i < Suppliers.Length; ++i)
        {
            var supplierProduct = CalculateSupplierProduct(item, i);
            if(supplierProduct is not null)
            {
                selectedSupplierProducts.Add(supplierProduct);
            }
        }

        var selectedSupplierProduct = SelectSupplierProduct(selectedSupplierProducts, item);
        if(selectedSupplierProduct is not null)
        {
            var supplierIdx = Suppliers.WithIndex()
                .FirstOrDefault(x => x.Value.ID == selectedSupplierProduct.SupplierLink.ID, new KeyValuePair<int, SupplierLink>(-1, null)).Key;
            if(supplierIdx != -1)
            {
                item.GetQuantity(supplierIdx).Total = GetRequiredQuantity(item, selectedSupplierProduct);
            }
        }
    }

    private void CalculateQuantities(bool recreateItems)
    {
        SetObserving(false);

        if (recreateItems)
        {
            Items.Clear();
            foreach(var dataItem in OrderData)
            {
                var item = new StockForecastOrderingItem();
                item.Product.CopyFrom(dataItem.Product);
                item.Style.CopyFrom(dataItem.Style);
                item.Dimensions.CopyFrom(dataItem.Dimensions);
                item.OrderStrategy = ForecastOrderStrategyToProductOrderStrategy(OrderStrategy, item.Product.OrderStrategy);

                if(OrderType == StockForecastOrderingType.StockOrder)
                {
                    item.RequiredQuantity = dataItem.RequiredQuantity;
                }
                else
                {
                    foreach(var breakup in dataItem.GetRequiredQuantities())
                    {
                        item.RequiredQuantity += breakup.Quantity;
                        item.Breakups.Add(breakup);
                    }
                }
                Items.Add(item);
            }
        }

        foreach(var (itemIdx, item) in Items.WithIndex())
        {
            var quantities = new StockForecastOrderingItemQuantity[Suppliers.Length];
            for(int i = 0; i < Suppliers.Length; ++i)
            {
                quantities[i] = CreateQuantity(itemIdx);
            }

            item.SetQuantities(quantities);
        }

        foreach(var item in Items)
        {
            CalculateSupplierProduct(item);
        }
        SetObserving(true);
        DoChanged();
    }

    #region Order Strategy

    private SupplierProduct? SelectSupplierProduct(IEnumerable<SupplierProduct> supplierProducts, StockForecastOrderingItem item)
    {
        switch (item.OrderStrategy)
        {
            case SupplierProductOrderStrategy.Exact:
            case SupplierProductOrderStrategy.RoundUp:
                return supplierProducts.Where(x => x.Dimensions.Equals(item.Dimensions) && x.Style.ID == item.Style.ID)
                           .MinBy(x => x.CostPrice)
                    ?? supplierProducts.Where(x => x.Dimensions.Equals(item.Dimensions))
                        .MinBy(x => x.CostPrice);
            
            case SupplierProductOrderStrategy.LowestOverallPrice:
                return supplierProducts.Where(x => x.Style.ID == item.Style.ID)
                           .MinBy(x => x.CostPrice *
                                       Math.Ceiling(item.RequiredQuantity * item.Dimensions.Value / (x.Dimensions.Value.IsEffectivelyEqual(0.0) ? (item.Dimensions.Value.IsEffectivelyEqual(0.0) ? 1.0 : item.Dimensions.Value) : x.Dimensions.Value)))
                       ?? supplierProducts
                           .MinBy(x => x.CostPrice * Math.Ceiling(item.RequiredQuantity * item.Dimensions.Value / (x.Dimensions.Value.IsEffectivelyEqual(0.0) ? (item.Dimensions.Value.IsEffectivelyEqual(0.0) ? 1.0 : item.Dimensions.Value) : x.Dimensions.Value)));
            
            case SupplierProductOrderStrategy.LowestUnitPrice:
                return supplierProducts.Where(x => x.Style.ID == item.Style.ID)
                           .MinBy(x=>x.CostPrice * item.Dimensions.Value/(x.Dimensions.Value.IsEffectivelyEqual(0.0) ? (item.Dimensions.Value.IsEffectivelyEqual(0.0) ? 1.0 : item.Dimensions.Value) : x.Dimensions.Value))
                    ?? supplierProducts
                        .MinBy(x=>x.CostPrice * item.Dimensions.Value/(x.Dimensions.Value.IsEffectivelyEqual(0.0) ? (item.Dimensions.Value.IsEffectivelyEqual(0.0) ? 1.0 : item.Dimensions.Value) : x.Dimensions.Value));
            
            case SupplierProductOrderStrategy.LowestOverstock:
                return supplierProducts.Where(x => x.Style.ID == item.Style.ID)
                           .MinBy(x=>x.Dimensions.Value * Math.Ceiling(item.RequiredQuantity * item.Dimensions.Value / (x.Dimensions.Value.IsEffectivelyEqual(0.0) ? (item.Dimensions.Value.IsEffectivelyEqual(0.0) ? 1.0 : item.Dimensions.Value) : x.Dimensions.Value)))
                       ?? supplierProducts
                           .MinBy(x=>x.Dimensions.Value * Math.Ceiling(item.RequiredQuantity * item.Dimensions.Value / (x.Dimensions.Value.IsEffectivelyEqual(0.0) ? (item.Dimensions.Value.IsEffectivelyEqual(0.0) ? 1.0 : item.Dimensions.Value) : x.Dimensions.Value)));
                
            default:
                return null;
        }
    }

    private double GetRequiredQuantity(StockForecastOrderingItem item, SupplierProduct supplierProduct)
    {
        switch (item.OrderStrategy)
        {
            case SupplierProductOrderStrategy.Exact:
                return item.RequiredQuantity;
            case SupplierProductOrderStrategy.RoundUp:
                return Math.Ceiling(item.RequiredQuantity);
            case SupplierProductOrderStrategy.LowestOverallPrice:
            case SupplierProductOrderStrategy.LowestUnitPrice:
            case SupplierProductOrderStrategy.LowestOverstock:
                return Math.Ceiling(item.RequiredQuantity * item.Dimensions.Value / (supplierProduct.Dimensions.Value.IsEffectivelyEqual(0.0) ? (item.Dimensions.Value.IsEffectivelyEqual(0.0) ? 1.0 : item.Dimensions.Value) : supplierProduct.Dimensions.Value));
            default:
                return 0.0;
        }
    }

    #endregion

    private bool _loadedColumns = false;
    protected override DynamicGridColumns LoadColumns()
    {
        if (!_loadedData)
        {
            LoadData();
        }

        var columns = new DynamicGridColumns();
        columns.Add<StockForecastOrderingItem, string>(x => x.Product.Code, 120, "Product Code", "", Alignment.MiddleCenter);
        columns.Add<StockForecastOrderingItem, string>(x => x.Product.Name, 0, "Product Name", "", Alignment.MiddleLeft);
        columns.Add<StockForecastOrderingItem, string>(x => x.Dimensions.UnitSize, 80, "Size", "", Alignment.MiddleCenter);
        columns.Add<StockForecastOrderingItem, string>(x => x.Style.Code, 80, "Style", "", Alignment.MiddleCenter);
        columns.Add<StockForecastOrderingItem, double>(x => x.RequiredQuantity, 80, "Required", "", Alignment.MiddleCenter);

        if (!_loadedColumns)
        {
            ActionColumns.Clear();

            ActionColumns.Add(new DynamicImageColumn(Warning_Image) { Position = DynamicActionColumnPosition.Start });
            ActionColumns.Add(new DynamicImagePreviewColumn<StockForecastOrderingItem>(x => x.Product.Image) { Position = DynamicActionColumnPosition.Start });

            ActionColumns.Add(new DynamicTemplateColumn(row =>
            {
                var item = LoadItem(row);

                var box = new ComboBox();
                box.ItemsSource = Enum.GetValues<SupplierProductOrderStrategy>()
                    .Select(x => new KeyValuePair<SupplierProductOrderStrategy, string>(x, CoreUtils.Neatify(x.ToString())));
                box.DisplayMemberPath = "Value";
                box.SelectedValuePath = "Key";
                box.SelectedValue = item.CustomStrategy ? null : item.OrderStrategy;
                box.SelectionChanged += (o, e) =>
                {
                    if (box.SelectedValue is not SupplierProductOrderStrategy strategy) return;
                    item.OrderStrategy = strategy;
                    item.CustomStrategy = false;
                    CalculateSupplierProduct(item);
                    InvalidateRow(row);
                };
                box.Margin = new Thickness(2);
                box.VerticalContentAlignment = VerticalAlignment.Center;
                return box;
            })
            {
                HeaderText = "Order Strategy.",
                Width = 140
            });

            SupplierProductColumns = new DynamicActionColumn[Suppliers.Length];
            QuantityColumns = new DynamicActionColumn[Suppliers.Length];
            CostColumns = new DynamicActionColumn[Suppliers.Length];
            QuantityControls.Clear();

            for(int i = 0; i < Suppliers.Length; ++i)
            {
                InitialiseSupplierColumn(i);
            }

            ActionColumns.Add(new DynamicMenuColumn(BuildMenu));

            _loadedColumns = true;
        }

        return columns;
    }

    private void EditSupplierProductGrid(DynamicGrid<SupplierProduct> grid)
    {
        grid.OnCustomiseEditor += (sender, items, column, editor) =>
        {
            if(new Column<SupplierProduct>(x => x.SupplierLink.ID).IsEqualTo(column.ColumnName)
                || new Column<SupplierProduct>(x => x.Product.ID).IsEqualTo(column.ColumnName)
                || new Column<SupplierProduct>(x => x.Style.ID).IsEqualTo(column.ColumnName)
                || new Column<SupplierProduct>(x => x.Job.ID).IsEqualTo(column.ColumnName)
                || new Column<SupplierProduct>(x => x.Dimensions).IsEqualTo(column.ColumnName))
            {
                editor.Editable = editor.Editable.Combine(Editable.Disabled);
            }
        };
    }

    private void BuildMenu(DynamicMenuColumn column, CoreRow? row)
    {
        if (row is null) return;

        column.AddItem("New Supplier", null, row =>
        {
            if (row is null) return;

            var selection = new MultiSelectDialog<Supplier>(
                new Filter<Supplier>(x => x.ID).NotInList(Suppliers.Select(x => x.ID).ToArray()),
                Columns.None<Supplier>().Add(x => x.ID).Add(x => x.Code), multiselect: false);
            if (selection.ShowDialog() != true)
            {
                return;
            }

            var supplier = selection.Data().Rows.First().ToObject<Supplier>();
            var productInstance = LoadItem(row);

            var supplierProduct = new SupplierProduct();
            supplierProduct.Product.CopyFrom(productInstance.Product);
            supplierProduct.Style.CopyFrom(productInstance.Style);
            supplierProduct.Dimensions.CopyFrom(productInstance.Dimensions);
            supplierProduct.SupplierLink.CopyFrom(supplier);

            if (DynamicGridUtils.EditEntity(supplierProduct, customiseGrid: EditSupplierProductGrid))
            {
                SupplierProducts.Add(supplierProduct);
                var newSuppliers = new SupplierLink[Suppliers.Length + 1];
                var newIdx = Suppliers.Length;

                for (int i = 0; i < Suppliers.Length; i++)
                {
                    newSuppliers[i] = Suppliers[i];
                }
                newSuppliers[newIdx] = supplierProduct.SupplierLink;

                foreach (var (itemIdx, item) in Items.WithIndex())
                {
                    var quantities = new StockForecastOrderingItemQuantity[newSuppliers.Length];
                    for (int i = 0; i < Suppliers.Length; ++i)
                    {
                        quantities[i] = item.GetQuantity(i);
                    }
                    var newQty = CreateQuantity(itemIdx);

                    quantities[newIdx] = newQty;
                    newQty.Total = 0;
                    item.SetQuantities(quantities);
                }

                Suppliers = newSuppliers;

                Refresh(true, true);
            }
        });
    }

    private BitmapImage? Warning_Image(CoreRow? row)
    {
        if (row is null) return _warning;

        var item = LoadItem(row);
        if(item.GetTotalQuantity(OrderType) < item.RequiredQuantity)
        {
            return _warning;
        }
        else
        {
            return null;
        }
    }

    protected override void ConfigureColumnGroups()
    {
        for(int idx = 0; idx < Suppliers.Length; ++idx)
        {
            GetColumnGrouping().AddGroup(Suppliers[idx].Code, SupplierProductColumns[idx], CostColumns[idx]);
        }
    }

    private class QuantityControl : ContentControl
    {
        private readonly StockForecastOrderingItem Item;
        private readonly int SupplierIndex;
        private readonly StockForecastOrderingGrid Parent;

        public QuantityControl(StockForecastOrderingGrid parent, StockForecastOrderingItem item, int supplierIndex, StockForecastOrderingType mode)
        {
            Parent = parent;
            Item = item;
            SupplierIndex = supplierIndex;

            UpdateControl(mode);
        }

        public void UpdateControl(StockForecastOrderingType mode)
        {
            // If no supplier product has been selected for this cell, we can't allow the user to select a quantity.
            if(Item.GetQuantity(SupplierIndex).SupplierProduct is null)
            {
                Content = null;
                return;
            }

            // Otherwise, simple quantity textbox editor.
            var editor = new DoubleTextBox
            {
                VerticalAlignment = VerticalAlignment.Stretch,
                HorizontalAlignment = HorizontalAlignment.Stretch,
                Background = new SolidColorBrush(Colors.LightYellow),
                BorderThickness = new Thickness(0.0),
                MinValue = 0.0,
                Value = Item.GetQuantity(SupplierIndex).Total
            };
            editor.ValueChanged += (o, e) =>
            {
                Item.GetQuantity(SupplierIndex).Total = editor.Value ?? default;
            };
            Content = editor;
        }
    }

    private List<QuantityControl> QuantityControls = [];

    private void InitialiseSupplierColumn(int idx)
    {
        var contextMenuFunc = (CoreRow[]? rows) =>
        {
            var row = rows?.FirstOrDefault();
            if (row is null) return null;

            var item = LoadItem(row);

            var menu = new ContextMenu();
            menu.AddItem("Create Supplier Product", null, new Tuple<StockForecastOrderingItem, int>(item, idx), CreateSupplierProduct_Click);
            return menu;
        };

        var qtyColumn = new Tuple<DynamicActionColumn, QuantityControl?>(null!, null);
        SupplierProductColumns[idx] = new DynamicTemplateColumn(row =>
        {
            var instance = LoadItem(row);

            var comboBox = new ComboBox();

            var items = SupplierProducts.Where(x => x.SupplierLink.ID == Suppliers[idx].ID && x.Product.ID == instance.Product.ID)
                .Select(x => new KeyValuePair<SupplierProduct?, string>(
                    x,
                    x.Style.ID != Guid.Empty ? $"{x.Dimensions.UnitSize}/{x.Style.Code}" : $"{x.Dimensions.UnitSize}"))
                .ToArray();
            comboBox.SelectedValuePath = "Key";

            comboBox.ItemsSource = items;
            comboBox.DisplayMemberPath = "Value";

            var qty = instance.GetQuantity(idx);

            comboBox.Bind(ComboBox.SelectedValueProperty, qty, x => x.SupplierProduct);
            comboBox.SelectionChanged += (o, e) =>
            {
                instance.CustomStrategy = true;
                InvalidateRow(row);
            };

            comboBox.VerticalContentAlignment = VerticalAlignment.Center;
            comboBox.Margin = new Thickness(2);
            if(items.Length == 0)
            {
                comboBox.IsEnabled = false;
            }

            return comboBox;
        })
        {
            HeaderText = "Supplier Product.",
            Width = 80
        };
        QuantityColumns[idx] = new DynamicTemplateColumn(row =>
        {
            var instance = LoadItem(row);
            var control = new QuantityControl(this, instance, idx, OrderType);
            QuantityControls.Add(control);
            return control;
        })
        {
            HeaderText = "Qty.",
            Width = 80,
            ContextMenu = contextMenuFunc
        };
        CostColumns[idx] = new DynamicTextColumn(row =>
        {
            if(row is null)
            {
                return "Cost";
            }

            var instance = LoadItem(row);
            var qty = instance.GetQuantity(idx);//.Total;
            if(qty.SupplierProduct is not null)
            {
                return $"{qty.Total * qty.SupplierProduct.CostPrice:C2}";
            }
            else
            {
                return "";
            }
        })
        {
            HeaderText = "Cost",
            Width = 80,
            ContextMenu = contextMenuFunc,
            GetSummary = () =>
            {
                var summary = new GridSummaryColumn
                {
                    Format = "{Sum:C2}",
                    SummaryType = Syncfusion.Data.SummaryType.Custom,
                    CustomAggregate = new CostAggregate(idx, this)
                };
                return summary;
            }
        };
        ActionColumns.Add(SupplierProductColumns[idx]);
        ActionColumns.Add(QuantityColumns[idx]);
        ActionColumns.Add(CostColumns[idx]);
    }

    private void CreateSupplierProduct_Click(Tuple<StockForecastOrderingItem, int> tuple)
    {
        var (item, supplierIdx) = tuple;

        var supplierProduct = new SupplierProduct();
        supplierProduct.Product.CopyFrom(item.Product);
        supplierProduct.Style.CopyFrom(item.Style);
        supplierProduct.Dimensions.CopyFrom(item.Dimensions);
        supplierProduct.SupplierLink.CopyFrom(Suppliers[supplierIdx]);

        if (DynamicGridUtils.EditEntity(supplierProduct, customiseGrid: EditSupplierProductGrid))
        {
            SupplierProducts.Add(supplierProduct);
            var qty = item.GetQuantity(supplierIdx);
            if(qty.SupplierProduct is null)
            {
                CalculateSupplierProduct(item, supplierIdx);
            }
            InvalidateGrid();
        }
    }

    private class CostAggregate : ISummaryAggregate
    {
        public double Sum { get; private set; }

        private int SupplierIndex;

        private StockForecastOrderingGrid Grid;

        public CostAggregate(int supplierIndex, StockForecastOrderingGrid grid)
        {
            SupplierIndex = supplierIndex;
            Grid = grid;
        }

        public Action<IEnumerable, string, PropertyDescriptor> CalculateAggregateFunc()
        {
            return AggregateFunc;
        }

        private void AggregateFunc(IEnumerable items, string property, PropertyDescriptor args)
        {
            if (items is IEnumerable<DataRowView> rows)
            {
                Sum = 0;
                foreach (var dataRow in rows)
                {
                    var rowIdx = dataRow.Row.Table.Rows.IndexOf(dataRow.Row);
                    var item = Grid.LoadItem(Grid.Data.Rows[rowIdx]);

                    var qty = item.GetQuantity(SupplierIndex);
                    if(qty.SupplierProduct is not null)
                    {
                        Sum += qty.Total * qty.SupplierProduct.CostPrice;
                    }
                }
            }
            else
            {
                Logger.Send(LogType.Error, "", $"Attempting to calculate aggregate on invalid data type '{items.GetType()}'.");
            }
        }
    }
}