using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using InABox.Clients;
using InABox.Core;
using InABox.WPF;
using RoslynPad.Editor;

namespace InABox.DynamicGrid
{
    public delegate void OnUpdateOtherEditorHandler(string columnname, object value);

    public delegate Dictionary<string, object?> EditorValueChangedHandler(object sender, string name, object value);

    /// <summary>
    ///     Interaction logic for DynamicEditorGrid.xaml
    /// </summary>
    public partial class DynamicEditorGrid : UserControl, IDynamicEditorHost
    {
        public delegate void EditorCreatedHandler(object sender, double height, double width);

        public delegate Document? FindDocumentEvent(string FileName);

        public delegate Document? GetDocumentEvent(Guid id);

        public delegate object? GetPropertyValueHandler(object sender, string name);

        public delegate void SaveDocumentEvent(Document document);

        public delegate void SetPropertyValueHandler(object sender, string name, object value);

        public delegate object?[] GetItemsEvent();

        // Column Definitions as defined by calling model
        private DynamicGridColumns _columns = new();

        private Type? LayoutType;
        private DynamicEditorGridLayout? Layout;

        private bool _tabStripVisible = true;
        
        public bool TabStripVisible
        {
            get { return _tabStripVisible; }
            set
            {
                _tabStripVisible = value;
                if (Layout != null) 
                    Layout.TabStripVisible = value;
            }
        }

        public DynamicEditorGrid()
        {
            InitializeComponent();

            Loaded += DynamicEditorGrid_Loaded;
        }

        public DynamicEditorPages Pages { get; private set; } = new();

        public bool PreloadPages { get; set; }

        public Type UnderlyingType { get; set; }

        public OnLoadPage? OnLoadPage { get; set; }
        public event OnSelectPage? OnSelectPage;
        public event OnUnloadPage? OnUnloadPage;

        public DynamicGridColumns Columns => _columns;

        public bool TryFindEditor(string columnname, [NotNullWhen(true)] out IDynamicEditorControl? editor)
        {
            foreach (var page in Pages)
            {
                if (page is DynamicEditPage editPage)
                {
                    if (editPage.TryFindEditor(columnname, out editor))
                        return true;
                }
            }
            editor = null;
            return false;
        }
        public IDynamicEditorControl? FindEditor(string columnname)
        {
            TryFindEditor(columnname, out var editor);
            return editor;
        }

        public virtual void ReconfigureEditors()
        {
            OnReconfigureEditors?.Invoke(this);
        }

        public object? GetPropertyValue(string columnname)
        {
            return OnGetPropertyValue?.Invoke(this, columnname);
        }

        public event EditorCreatedHandler? OnEditorCreated;

        public event OnCustomiseColumns? OnCustomiseColumns;

        public event OnGetEditor? OnGetEditor;

        public event OnGridCustomiseEditor? OnGridCustomiseEditor;

        public event OnGetEditorSequence? OnGetSequence;
        public event GetPropertyValueHandler? OnGetPropertyValue;
        public event SetPropertyValueHandler? OnSetPropertyValue;

        public event EditorValueChangedHandler? OnEditorValueChanged;

        public event OnAfterEditorValueChanged? OnAfterEditorValueChanged;

        public event OnReconfigureEditors? OnReconfigureEditors;
        
        public event OnDefineFilter? OnDefineFilter;

        public event OnDefineLookup? OnDefineLookups;

        public event GetDocumentEvent? OnGetDocument;
        public event FindDocumentEvent? OnFindDocument;
        public event SaveDocumentEvent? OnSaveDocument;

        public event GetItemsEvent? GetItems;

        private void DynamicEditorGrid_Loaded(object sender, RoutedEventArgs e)
        {
            //Reload();
        }

        public void Reload()
        {
            LoadPages();
            ReconfigureEditors();
        }

        #region Host Implementation

        IEnumerable<DynamicGridColumn> IDynamicEditorHost.Columns => Columns;

        public void LoadColumns(string column, Dictionary<string, string> columns)
        {
            columns.Clear();
            var comps = column.Split('.').ToList();
            comps.RemoveAt(comps.Count - 1);
            var prefix = string.Format("{0}.", string.Join(".", comps));
            var cols = Columns.Where(x => !x.ColumnName.Equals(column) && x.ColumnName.StartsWith(prefix));
            foreach (var col in cols)
                columns[col.ColumnName.Replace(prefix, "")] = col.ColumnName;
        }

        public IFilter? DefineFilter(Type type) => OnDefineFilter?.Invoke(type);

        public void LoadLookups(ILookupEditorControl editor)
        {
            OnDefineLookups?.Invoke(editor);
        }

        public Document? FindDocument(string filename) => OnFindDocument?.Invoke(filename);

        public Document? GetDocument(Guid id) => OnGetDocument?.Invoke(id);

        public void SaveDocument(Document document) => OnSaveDocument?.Invoke(document);

        object?[] IDynamicEditorHost.GetItems() => GetItems?.Invoke() ?? Array.Empty<object?>();

        public BaseEditor? GetEditor(DynamicGridColumn column) => OnGetEditor?.Invoke(column);

        #endregion

        #region Edit Page

        public class DynamicEditPage : ContentControl, IDynamicEditorPage
        {

            private Grid Grid;

            public DynamicEditorGrid EditorGrid { get; set; } = null!; // Set by DynamicEditorGrid
            public bool Ready { get; set; }

            private List<BaseDynamicEditorControl> Editors { get; set; }

            public PageType PageType => PageType.Editor;

            public int PageOrder { get; set; }

            public string Header { get; set; }

            private double GeneralHeight = 30;

            public DynamicEditPage(string header)
            {
                Header = header;

                Editors = new List<BaseDynamicEditorControl>();

                InitialiseContent();
            }

            public void AddEditor(string columnName, BaseEditor editor)
            {
                BaseDynamicEditorControl? element = DynamicEditorControlFactory.CreateControl(editor, EditorGrid);
                
                if (element != null)
                {
                    element.EditorDefinition = editor;

                    element.IsEnabled = editor.Editable == Editable.Enabled;

                    if (!string.IsNullOrWhiteSpace(editor.ToolTip))
                    {
                        element.ToolTip = new ToolTip() { Content = editor.ToolTip };
                    }

                    var label = new Label();
                    label.Content = CoreUtils.Neatify(editor.Caption); // 2
                    label.Margin = new Thickness(0F, 0F, 0F, 0F);
                    label.HorizontalAlignment = HorizontalAlignment.Stretch;
                    label.VerticalAlignment = VerticalAlignment.Stretch;
                    label.HorizontalContentAlignment = HorizontalAlignment.Left;
                    label.VerticalContentAlignment = VerticalAlignment.Center;
                    label.SetValue(Grid.RowProperty, Grid.RowDefinitions.Count);
                    label.SetValue(Grid.ColumnProperty, 0);
                    label.Visibility = string.IsNullOrWhiteSpace(editor.Caption) ? Visibility.Collapsed : Visibility.Visible;

                    Grid.Children.Add(label);

                    element.ColumnName = columnName;
                    element.Color = editor is UniqueCodeEditor ? Color.FromArgb(0xFF, 0xF6, 0xC9, 0xE8) : Colors.LightYellow;

                    Editors.Add(element);

                    element.Margin = new Thickness(5F, 2.5F, 5F, 2.5F);

                    double iHeight = element.DesiredHeight();
                    if (iHeight == int.MaxValue)
                    {
                        Grid.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1, GridUnitType.Star) });
                        GeneralHeight += element.MinHeight + 5.0F;
                    }
                    else
                    {
                        Grid.RowDefinitions.Add(new RowDefinition { Height = new GridLength(iHeight + 5.0F) });
                        GeneralHeight += iHeight + 5.0F;
                    }

                    double iWidth = element.DesiredWidth();
                    if (iWidth == int.MaxValue)
                    {
                        element.HorizontalAlignment = HorizontalAlignment.Stretch;
                    }
                    else
                    {
                        element.HorizontalAlignment = HorizontalAlignment.Left;
                        element.Width = iWidth;
                    }

                    element.SetValue(Grid.RowProperty, Grid.RowDefinitions.Count - 1);
                    element.SetValue(Grid.ColumnProperty, 1);
                    Grid.Children.Add(element);
                }
            }

            [MemberNotNull(nameof(Grid))]
            private void InitialiseContent()
            {
                Grid = new Grid
                {
                    HorizontalAlignment = HorizontalAlignment.Stretch,
                    VerticalAlignment = VerticalAlignment.Stretch,
                    Margin = new Thickness(0, 2.5, 0, 2.5)
                };
                Grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Auto) });
                Grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });

                var scroll = new ScrollViewer
                {
                    HorizontalAlignment = HorizontalAlignment.Stretch,
                    VerticalAlignment = VerticalAlignment.Stretch,
                    VerticalScrollBarVisibility = ScrollBarVisibility.Auto,
                    Padding = new Thickness(2),
                    Content = Grid
                };

                var border = new Border
                {
                    BorderBrush = new SolidColorBrush(Colors.Gray),
                    Background = new SolidColorBrush(Colors.White),
                    BorderThickness = new Thickness(0.75),
                    Child = scroll
                };

                Content = border;
            }

            public void AfterSave(object item)
            {
            }

            public void BeforeSave(object item)
            {
            }

            public string Caption() => Header;

            public bool TryFindEditor(string columnname, [NotNullWhen(true)] out IDynamicEditorControl? editor)
            {
                editor = Editors.FirstOrDefault(x => x.ColumnName.Equals(columnname));
                editor ??= Editors.FirstOrDefault(x => columnname.StartsWith(x.ColumnName + '.'));
                return editor is not null;
            }

            public IEnumerable<BaseDynamicEditorControl> FindEditors(DynamicGridColumn column)
            {
                return Editors.Where(x => string.Equals(x.ColumnName, column.ColumnName));
            }

            #region Configure Editors

            private void Lookup_OnUpdateOtherEditor(string columnname, object value)
            {
                var editor = Editors.FirstOrDefault(x => x.ColumnName.Equals(columnname));
                if (editor != null)
                    CoreUtils.SetPropertyValue(editor, "Value", value);
            }

            private void ConfigureEditors()
            {
                foreach (var Editor in Editors)
                {
                    var editor = Editor.EditorDefinition;
                    var column = Editor.ColumnName;

                    Editor.Configure();
                    if (!Editors.Any(x => x.ColumnName.Equals(Editor.ColumnName)))
                        Editors.Add(Editor);
                    Editor.Loaded = true;
                }
            }

            #endregion

            private void EditorValueChanged(IDynamicEditorControl sender, Dictionary<string, object> values)
            {
                //Logger.Send(LogType.Information, "", string.Format("DynamicEditorGrid.EditorValueChanged({0})", values.Keys.Count));
                var changededitors = new Dictionary<string, object?>();

                void ExtractChanged(Dictionary<String, object?>? columns)
                {
                    if (columns != null)
                        foreach (var (change, value) in columns)
                            if (!changededitors.ContainsKey(change) && !change.Equals(sender.ColumnName))
                                changededitors[change] = value;
                }

                foreach (var key in values.Keys)
                {
                    var changedcolumns = EditorGrid.OnEditorValueChanged?.Invoke(EditorGrid, key, values[key]);
                    ExtractChanged(changedcolumns);
                }

                var afterchanged = EditorGrid.OnAfterEditorValueChanged?.Invoke(EditorGrid, sender.ColumnName);
                ExtractChanged(afterchanged);

                if (changededitors.Any())
                    LoadEditorValues(changededitors);

                EditorGrid.ReconfigureEditors();
            }

            private void LoadEditorValues(Dictionary<string, object?>? changededitors = null)
            {
                var columnnames = changededitors != null ? changededitors.Keys.ToArray() : Editors.Select(x => x.ColumnName).ToArray();
                foreach (var columnname in columnnames)
                {
                    if (!TryFindEditor(columnname, out var editor))
                        continue;

                    var bLoaded = editor.Loaded;
                    editor.Loaded = false;
                    if (changededitors != null && changededitors.ContainsKey(columnname))
                    {
                        editor.SetValue(columnname, changededitors[columnname]);
                    }
                    else
                    {
                        var curvalue = EditorGrid.GetPropertyValue(columnname);

                        try
                        {
                            editor.SetValue(columnname, curvalue);
                        }
                        catch (Exception e)
                        {
                            MessageBox.Show($"Unable to set editor value for {columnname} -> {curvalue}: {CoreUtils.FormatException(e)}");
                        }

                        editor.Changed = false;
                    }

                    editor.Loaded = bLoaded;

                    editor.OnEditorValueChanged += EditorValueChanged;
                }
            }

            public void Load(object item, Func<Type, CoreTable>? PageDataHandler)
            {
                ConfigureEditors();
                LoadEditorValues();

                foreach (var editor in Editors)
                {
                    foreach(var (column, editorValue) in editor.GetValues())
                    {
                        var entityValue = EditorGrid.GetPropertyValue(column);
                        if (!Equals(editorValue, entityValue))
                        {
                            bool bLoaded = editor.Loaded;
                            editor.Loaded = false;
                            editor.SetValue(column, entityValue);
                            editor.Loaded = bLoaded;
                        }
                    }
                }

                Editors.FirstOrDefault()?.SetFocus();

                Ready = true;
            }

            public Size MinimumSize() => new Size(800, GeneralHeight);

            public int Order() => PageOrder;
        }

        #endregion

        #region Loading + Editing Layout

        private decimal GetSequence(DynamicGridColumn column)
        {
            if (OnGetSequence != null)
                return OnGetSequence.Invoke(column);
            return 999;
        }

        private DynamicEditPage GetEditPage(string name)
        {
            var page = Pages.Where(x => x is DynamicEditPage page && page.Header == name).FirstOrDefault() as DynamicEditPage;
            if(page is null)
            {
                page = new DynamicEditPage(name)
                {
                    // Setting this here because it's needed now to be able to create the layout.
                    EditorGrid = this
                };
                if (name == "General")
                {
                    page.PageOrder = -1;
                }
                else
                {
                    page.PageOrder = 0;
                }

                Pages.Add(page);
            }
            return page;
        }

        public void SetLayoutType<T>() where T : DynamicEditorGridLayout
        {
            LayoutType = typeof(T);
        }

        private void InitialiseLayout()
        {
            Layout = (Activator.CreateInstance(LayoutType ?? typeof(DefaultDynamicEditorGridLayout)) as DynamicEditorGridLayout)!;
            Layout.OnSelectPage += Layout_SelectPage;
            Layout.TabStripVisible = _tabStripVisible;

            Content = Layout;
        }

        private void CreateLayout()
        {
            if(Layout is null)
            {
                InitialiseLayout();
            }

            foreach (var column in _columns.OrderBy(x => GetSequence(x)))
            {
                var iProp = DatabaseSchema.Property(UnderlyingType, column.ColumnName);
                var editor = OnGetEditor?.Invoke(column);

                if (editor != null && iProp?.ShouldShowEditor() != true)
                {
                    editor.Visible = Visible.Hidden;
                    editor.Editable = Editable.Hidden;
                }

                if(editor is not null)
                {
                    OnGridCustomiseEditor?.Invoke(this, column, editor);
                }

                if (editor != null && editor.Editable != Editable.Hidden)
                {
                    var page = string.IsNullOrWhiteSpace(editor.Page) ? iProp is StandardProperty ? "General" : "Custom Fields" : editor.Page;
                    var editPage = GetEditPage(page);

                    editPage.AddEditor(column.ColumnName, editor);
                }
                else if (iProp?.HasParentEditor() == true)
                {
                    var parent = iProp.GetParentWithEditor();
                    if(parent is not null)
                    {
                        var parentEditor = parent.Editor;

                        if(parentEditor is not null)
                        {
                            OnGridCustomiseEditor?.Invoke(this, new DynamicGridColumn { ColumnName = parent.Name }, parentEditor);
                        }
                        if(parentEditor is not null && parentEditor.Editable != Editable.Hidden)
                        {
                            var page = string.IsNullOrWhiteSpace(parentEditor.Page)
                                ? parent is StandardProperty
                                    ? "General"
                                    : "Custom Fields"
                                : parentEditor.Page;

                            var editPage = GetEditPage(page);
                            if (!editPage.TryFindEditor(parent.Name, out var editorControl))
                            {
                                editPage.AddEditor(parent.Name, parentEditor);
                            }
                        }
                    }
                }
            }
            
            OnEditorCreated?.Invoke(this, 0, 800);
        }

        #endregion

        #region Pages

        private void Layout_SelectPage(IDynamicEditorPage page)
        {
            if (!page.Ready)
                using (new WaitCursor())
                {
                    OnLoadPage?.Invoke(page);
                }

            OnSelectPage?.Invoke(this, null);
        }

        public void UnloadPages(bool saved)
        {
            if(Pages is not null)
                foreach (var page in Pages)
                    if (page.Ready)
                        OnUnloadPage?.Invoke(page, saved);
        }

        private void LoadPages()
        {
            if (Pages != null && Layout is not null)
                using (new WaitCursor())
                {
                    foreach (var page in Pages)
                    {
                        page.Ready = false;
                        page.EditorGrid = this;
                    }
                    Layout.LoadPages(Pages);

                    if (PreloadPages)
                    {
                        foreach(var page in Pages)
                        {
                            OnLoadPage?.Invoke(page);
                        }
                    }
                }
        }

        public void Load(DynamicEditorPages pages)
        {
            Pages = pages;

            _columns = new DynamicGridColumns();
            OnCustomiseColumns?.Invoke(this, _columns);

            CreateLayout();
            Reload();
        }

        #endregion

    }
}