using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Imaging;
using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using InABox.DynamicGrid;
using InABox.Wpf;
using InABox.WPF;
using PRSDimensionUtils;

namespace PRSDesktop.Grids;

public class ProductDimensionUnitGrid : DynamicDataGrid<ProductDimensionUnit>
{

    private static readonly BitmapImage CONVERT = PRSDesktop.Resources.specifications.AsBitmapImage();
    private Button ConvertButton = null!;
    
    protected override void Init()
    {
        base.Init();

        HiddenColumns.Add(x => x.Code);
        HiddenColumns.Add(x => x.HasQuantity);
        HiddenColumns.Add(x => x.HasLength);
        HiddenColumns.Add(x => x.HasWeight);
        HiddenColumns.Add(x => x.HasWidth);
        HiddenColumns.Add(x => x.HasHeight);
        HiddenColumns.Add(x =>x.Conversion);
        
        ActionColumns.Add(new DynamicImageColumn(ConvertImage) { Position = DynamicActionColumnPosition.End});
        
        AddButton("Update Expressions", null, (button, rows) =>
        {
            UpdateExpressions(rows.ToArray<ProductDimensionUnit>());
            return false;
        });
        ConvertButton = AddButton("Convert Movements", null, (button, rows) =>
        {
            UpdateConversion(rows.ToArray<ProductDimensionUnit>());
            return false;
        });
    }

    protected override void SelectItems(CoreRow[]? rows)
    {
        base.SelectItems(rows);

        if(!(rows?.FirstOrDefault()?.Get<ProductDimensionUnit, string>(x => x.Conversion)).IsNullOrWhiteSpace())
        {
            ConvertButton.Visibility = Visibility.Visible;
        }
        else
        {
            ConvertButton.Visibility = Visibility.Collapsed;
        }
    }

    private BitmapImage? ConvertImage(CoreRow? row)
    {
        return row == null
            ? CONVERT
            : String.IsNullOrWhiteSpace(row.Get<ProductDimensionUnit, string>(x => x.Conversion))
                ? null
                : CONVERT;
    }

    protected override void DoValidate(ProductDimensionUnit[] items, List<string> errors)
    {
        base.DoValidate(items, errors);
        foreach (var item in items)
            item.Validate(errors);
    }

    private static void UpdateConversion(ProductDimensionUnit[] items)
    {
        int? nMovements = null;
        Exception? exception = null;

        var filter = new Filter<StockMovement>(x => x.Dimensions.Unit.ID).InList(items.ToArray(x => x.ID));
        var columns = Columns.Required<StockMovement>()
            .Add(x => x.Units)
            .Add(x => x.Received)
            .Add(x => x.Issued)
            .AddDimensionsColumns(x => x.Dimensions, Dimensions.ColumnsType.Local);
        var nTotal = Client.Query(filter, Columns.None<StockMovement>().Add(x => x.ID)).Rows.Count;

        if(!MessageWindow.ShowYesNo($"This will potentially update the dimensions of {nTotal} stock movements, and this cannot be reversed. Are you sure you wish to proceed?", "Confirm"))
        {
            return;
        }

        Progress.ShowModal("Updating Dimensions", progress =>
        {
            try
            {
                progress.Report($"Updating Stock Movements");

                var nProcessed = 0;
                var nResult = 0;
                var done = false;

                var percentStep = Math.Max(nTotal / 100, 1);
                var range = CoreRange.Database(1000);

                while(nProcessed < nTotal && !done)
                {
                    var rows = Client.Query(filter, columns, range: range).Rows;
                    if (rows.Count == 0) break;
                    if(rows.Count < 1000)
                    {
                        done = true;
                    }
                    range.Next();

                    var results = new List<StockMovement>(rows.Count);
                    for(int i = 0; i < rows.Count; ++i)
                    {
                        if(nProcessed % percentStep == 0)
                        {
                            progress.Report($"Updating Stock Movements: {(double)nProcessed / (double)nTotal * 100:F0}%");
                        }
                        var mvt = rows[i].ToObject<StockMovement>();
                        var qty = DimensionUtils.ConvertDimensions(mvt.Dimensions, mvt.Units, Client<ProductDimensionUnit>.Provider);
                        if(qty >= 0)
                        {
                            mvt.Received = qty;
                            mvt.Issued = 0;
                        }
                        else
                        {
                            mvt.Received = 0;
                            mvt.Issued = -qty;
                        }
                        if (mvt.IsChanged())
                        {
                            results.Add(mvt);
                            nResult++;
                        }
                        nProcessed++;
                    }
                    Client.Save(results, "Updated conversion script.");
                }

                nMovements = nResult;
            }
            catch(Exception e)
            {
                exception = e;
            }
        });
        if(nMovements is not null)
        {
            MessageWindow.ShowMessage($"Update successful: {nMovements.Value} movements updated.", "Success");
        }
        else if(exception is not null)
        {
            MessageWindow.ShowError("Error while updating dimensions", exception);
        }
    }

    private static void UpdateExpressions(ProductDimensionUnit[] items)
    {
        Dictionary<Type, int>? results = null;
        Exception? exception = null;
        Progress.ShowModal("Updating Dimensions", progress =>
        {
            try
            {
                results = DimensionUnitUtils.UpdateExpressions<ProductDimensionUnit, ProductDimensionUnitLink>(items, progress);
            }
            catch(Exception e)
            {
                exception = e;
            }
        });
        if(results is not null)
        {
            MessageWindow.ShowMessage($"Update successful:\n{string.Join("\n", results.Select(x => $"- {x.Key.Name}: {x.Value} items updated"))}", "Success");
        }
        else if(exception is not null)
        {
            MessageWindow.ShowError("Error while updating dimensions", exception);
        }
    }

    private bool ShouldUpdateExpressions = false;

    protected override void DoBeforeSave(IDynamicEditorForm editor, ProductDimensionUnit[] items)
    {
        base.DoBeforeSave(editor, items);

        ShouldUpdateExpressions = false;
        if(items.Any(x => x.HasOriginalValue(x => x.Format) || x.HasOriginalValue(x => x.Formula)))
        {
            if(MessageWindow.ShowYesNo("The format and/or formula has been changed; do you wish to update the UnitSize/Value of every item that uses dimension to match the new expression? (This may take a while)", "Update expressions?"))
            {
                ShouldUpdateExpressions = true;
            }
        }
    }

    protected override void DoAfterSave(IDynamicEditorForm editor, ProductDimensionUnit[] items)
    {
        base.DoAfterSave(editor, items);

        if (ShouldUpdateExpressions)
        {
            UpdateExpressions(items);
        }
    }

    protected override bool DoMerge(CoreRow[] rows)
    {
        var columns = new Column<ProductDimensionUnit>[]
        {
            new(x => x.HasLength),
            new(x => x.HasQuantity),
            new(x => x.HasHeight),
            new(x => x.HasWeight),
            new(x => x.HasWidth),
        };

        var target = rows[^1].ToObject<ProductDimensionUnit>();
        if(columns.Any(c => rows.Select(r => r[c.Property]).Distinct().Skip(1).Any()))
        {
            MessageWindow.ShowMessage("These dimension units are incompatible, and cannot be merged.\n\n(Dimension units can only be merged if they have the same [HasQuantity], [HasLength], [HasWidth], [HasHeight] and [HasWeight] values).", "Incompatible units", image: MessageWindow.WarningImage);
            return false;
        }

        if (base.DoMerge(rows))
        {
            if(MessageWindow.ShowYesNo(
                $"Do you wish to update the UnitSize/Value for every item that uses {target.Code}? (This may take a while)",
                "Update Expressions?"))
            {
                UpdateExpressions([target]);
            }

            return true;
        }
        return false;
    }

    protected override void CustomiseEditor(IDynamicEditorForm form, ProductDimensionUnit[] items, DynamicGridColumn column, BaseEditor editor)
    {
        base.CustomiseEditor(form, items, column, editor);
        if (column.ColumnName == nameof(ProductDimensionUnit.Conversion) && editor is ScriptEditor scriptEditor)
        {
            scriptEditor.Type = ScriptEditorType.TemplateEditor;
            scriptEditor.OnEditorClicked += () =>
            {
                var script = items.FirstOrDefault()?.Conversion.NotWhiteSpaceOr()
                             ?? DimensionUnit.DefaultConvertDimensionsScript();

                var editor = new ScriptEditorWindow(script, SyntaxLanguage.CSharp);
                if (editor.ShowDialog() == true)
                {
                    foreach (var item in items)
                        SetEditorValue(item, column.ColumnName, editor.Script);
                }
            };
        }
    }
}