using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Interop;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using InABox.Core;
using InABox.DynamicGrid.Properties;
using InABox.Wpf;
using InABox.WPF;
using Syncfusion.Windows.Shared;
using Syncfusion.Windows.Tools.Controls;

namespace InABox.DynamicGrid
{
    public delegate BaseEditor? DefineEditorEventHandler(object item, DynamicGridColumn column);

    public delegate void DynamicGridSaveEvent(object sender, CancelEventArgs args);

    public interface IDynamicEditorForm
    {
    }

    public class UtilityItem
    {
        public string Name { get; set; }
        public ImageSource Icon { get; set; }
        public string Text { get; set; }
        public SizeMode Mode { get; set; }
        public ICommand Command { get; set; }
    }

    public class UtilityViewModel
    {
        /// <summary>
        ///     Constructor of the UtilityViewModel class.
        /// </summary>
        public UtilityViewModel()
        {
            var utilities = new ObservableCollection<UtilityItem>();
            utilities.Add(new UtilityItem
                { Name = "Help", Icon = Resources.help.AsBitmapImage(), Text = "", Mode = SizeMode.Normal, Command = HelpCommand });
            Utilities = utilities;
        }

        /// <summary>
        ///     Collection containing the complete details of the items to be bound in the title bar.
        /// </summary>
        public ObservableCollection<UtilityItem> Utilities { get; }

        /// <summary>
        ///     Commmand for the Help button.
        /// </summary>
        public DelegateCommand HelpCommand => new(HelpCommandAction);

        public static string Slug { get; set; }

        /// <summary>
        ///     Action that is performed when clicking the help button.
        /// </summary>
        private void HelpCommandAction(object param)
        {
            Process.Start("https://prs-software.com.au/wiki/index.php/" + Slug);
        }
    }

    /// <summary>
    ///     Interaction logic for DynamicEditor.xaml
    /// </summary>
    public partial class DynamicEditorForm : ThemableChromelessWindow, IDynamicEditorForm
    {
        public delegate Document? FindDocumentEvent(string FileName);

        public delegate Document? GetDocumentEvent(Guid id);

        public delegate void SaveDocumentEvent(Document document);

        private BaseObject[] _items;

        public DynamicEditorGrid Editor;

        public DynamicEditorForm(Type type, DynamicEditorPages? pages = null, DynamicEditorButtons? buttons = null,
            Func<Type, CoreTable>? PageDataHandler = null, bool PreloadPages = false)
        {
            ReadOnly = false;

            InitializeComponent();

            //this.Loaded += new RoutedEventHandler(ConfigureSystemMenu);

            var grid = Content as Grid;
            Editor = grid.Children.OfType<DynamicEditorGrid>().FirstOrDefault();

            Editor.UnderlyingType = type;

            Editor.OnCustomiseColumns += Editor_OnCustomiseColumns;

            Editor.OnDefineFilter += (sender, t) => OnDefineFilter?.Invoke(sender, t);

            Editor.OnEditorCreated += Editor_OnEditorCreated;

            Editor.OnLoadPage += page => { page.Load(Items.First(), PageDataHandler); };

            Editor.OnSelectPage += (tab, items) => { OnSelectPage?.Invoke(tab, items); };

            Editor.PreloadPages = PreloadPages;

            Editor.OnUnloadPage += (page, saved) =>
            {
                if (!saved)
                    page.BeforeSave(Items.First());
                else
                    page.AfterSave(Items.First());
            };

            //Editor.OnGetPropertyInfo += (o, c) => { return CoreUtils.GetProperty(_item.GetType(), c); };

            Editor.ReconfigureEditors += g => { ReconfigureEditors?.Invoke(g); };

            Editor.OnGetEditor += c =>
            {
                if (_items != null && _items.Any())
                {
                    var property = DatabaseSchema.Property(type, c.ColumnName);
                    if (property == null) return new NullEditor();

                    if (property.Editor is NullEditor)
                        return property.Editor;

                    BaseEditor editor;
                    if (property is CustomProperty)
                    {
                        editor = property.Editor.CloneEditor();
                    }
                    else
                    {
                        editor = OnDefineEditor?.Invoke(_items[0], c) ?? c.Editor.CloneEditor();
                        var propEditor = property.Editor;
                        editor.Page = propEditor.Page;
                        editor.Caption = propEditor.Caption;
                    }


                    //defaultEditor.EditorSequence

                    //EditorUtils.GetPropertyEditor(type, property, defaultEditor);

                    /*BaseEditor editor = new NullEditor();
                    var caption = "";
                    var page = "";

                    try
                    {
                        var comps = c.ColumnName.Split('.');
                        for (var i = 0; i < comps.Length; i++)
                        {
                            var column = string.Join(".", comps.Take(i + 1));
                            var prop = CoreUtils.GetProperty(type, column);

                            if (column.Equals(c.ColumnName))
                            {
                                if (OnDefineEditor != null)
                                    editor = OnDefineEditor(_items[0], c);
                                else
                                    editor = c.Editor != null ? c.Editor : new NullEditor();
                            }
                            else
                            {
                                var pedit = prop.GetEditor();
                                if (pedit is NullEditor)
                                    return pedit;
                            }

                            editor = editor == null ? new NullEditor() : editor.Clone() as BaseEditor;

                            var capattr = prop.GetCustomAttribute<Caption>();
                            var subcap = capattr != null ? capattr.Text : comps[i];
                            var path = capattr != null ? capattr.IncludePath : true;
                            if (!string.IsNullOrWhiteSpace(subcap))
                                caption = string.IsNullOrWhiteSpace(caption) || path == false ? subcap : string.Format("{0} {1}", caption, subcap);

                            if (string.IsNullOrWhiteSpace(page))
                            {
                                var pageattr = prop.GetCustomAttribute<EditorSequence>();
                                if (pageattr != null)
                                    page = pageattr.Page;
                            }
                        }

                        editor.Caption = caption;
                        editor.Page = page;
                    }
                    catch (Exception e)
                    {
                        var dmprop = DatabaseSchema.Property(_items[0].GetType(), c.ColumnName);
                        if (dmprop is CustomProperty)
                        {
                            editor = dmprop.Editor.Clone() as BaseEditor;
                            editor.Caption = dmprop.Caption;
                            editor.Page = string.IsNullOrWhiteSpace(dmprop.Page) ? "Custom Fields" : dmprop.Page;
                        }
                    }*/

                    if (ReadOnly && editor.Editable.Equals(Editable.Enabled))
                        editor.Editable = Editable.Disabled;
                    return editor;
                }

                return new NullEditor();
            };

            Editor.OnGridCustomiseEditor += (sender, column, editor) => OnFormCustomiseEditor?.Invoke(this, Items, column, editor);

            Editor.OnGetSequence += c => CoreUtils.GetPropertySequence(_items.First().GetType(), c.ColumnName);

            Editor.OnGetPropertyValue += (o, c) =>
            {
                if (!_items.Any())
                    return null;

                object? result;
                try
                {
                    result = CoreUtils.GetPropertyValue(_items.First(), c);
                }
                catch
                {
                    result = _items.First().UserProperties.ContainsKey(c) ? _items.First().UserProperties[c] : null;
                }

                if (result == null)
                    return null;

                foreach (var _item in _items)
                {
                    object? curvalue;
                    try
                    {
                        curvalue = CoreUtils.GetPropertyValue(_item, c);
                    }
                    catch
                    {
                        curvalue = _item.UserProperties.ContainsKey(c) ? _item.UserProperties[c] : null;
                    }

                    if (curvalue == null)
                        return null;

                    if (!curvalue.Equals(result))
                        return null;
                }

                return result;
            };

            Editor.OnSetPropertyValue += (o, c, v) =>
            {
                foreach (var _item in _items)
                    if (_item.UserProperties.ContainsKey(c))
                        _item.UserProperties[c] = v;
                    else
                        CoreUtils.SetPropertyValue(_item, c, v);
            };

            Editor.OnEditorValueChanged += EditorValueChanged;

            Editor.OnDefineLookups += sender => { OnDefineLookups?.Invoke(sender); };
            Editor.OnLookupsDefined += sender => { OnLookupsDefined?.Invoke(sender); };

            Editor.OnGetDocument += id => { return OnGetDocument?.Invoke(id); };
            Editor.OnSaveDocument += doc => { OnSaveDocument?.Invoke(doc); };
            Editor.OnFindDocument += file => { return OnFindDocument?.Invoke(file); };

            Pages = pages;

            if (Pages == null || Pages.Count == 0)
                Editor.Margin = new Thickness(5, 5, 5, 0);

            if (buttons != null)
                foreach (var button in buttons)
                {
                    var btn = new Button();
                    UpdateButton(btn, button.Image, button.Name);
                    btn.Tag = button;
                    btn.Margin = new Thickness(5, 5, 0, 5);
                    btn.Padding = new Thickness(5, 0, 5, 0);
                    btn.Click += Btn_Click;
                    Buttons.Children.Add(btn);
                    button.Button = btn;
                    button.Form = this;
                }
        }

        public DynamicEditorPages? Pages { get; }

        public BaseObject[] Items
        {
            get => _items;
            set
            {
                _items = value;
                UtilityViewModel.Slug = Items != null ? Items.Any() ? Items.First().GetType().EntityName().Split('.').Last() : "" : "";
                Editor.Load(_items.First().GetType().EntityName(), Pages);
            }
        }

        public bool ReadOnly { get; set; }

        public OnValidateData? OnValidateData;

        public event OnCustomiseColumns? OnCustomiseColumns;

        public event OnDefineFilter? OnDefineFilter;

        public event DefineEditorEventHandler? OnDefineEditor;

        public event OnFormCustomiseEditor? OnFormCustomiseEditor;

        public event OnReconfigureEditors? ReconfigureEditors;

        //public delegate void EditorValueChangedHandler(object sender, String name, object value, List<String> changes);
        //public event EditorValueChangedHandler OnEditorValueChanged;

        public event EditorValueChangedHandler? OnEditorValueChanged;

        //public event DefineFilter OnDefineFilter;

        public event OnDefineLookup? OnDefineLookups;

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

        public event OnSelectPage? OnSelectPage;

        public event DynamicGridSaveEvent? OnSaveItem;

        public void UnloadEditorPages(DynamicEditorPages pages, object item, bool saved)
        {
            Editor.UnloadPages(saved);
        }

        protected void UpdateButton(Button button, BitmapImage? image, string text)
        {
            var stackPnl = new StackPanel();
            stackPnl.Orientation = Orientation.Horizontal;
            //stackPnl.Margin = new Thickness(2);

            if (image != null)
            {
                var img = new Image();
                img.Source = image;
                img.Margin = new Thickness(2);
                stackPnl.Children.Add(img);
            }

            if (!string.IsNullOrEmpty(text))
            {
                var lbl = new Label();
                lbl.Content = text;
                lbl.VerticalAlignment = VerticalAlignment.Stretch;
                lbl.VerticalContentAlignment = VerticalAlignment.Center;
                lbl.Margin = new Thickness(2, 0, 5, 0);
                stackPnl.Children.Add(lbl);
            }

            button.Content = stackPnl;
        }

        private Dictionary<string, object?> EditorValueChanged(object sender, string name, object value)
        {
            if (OnEditorValueChanged != null)
                return OnEditorValueChanged(sender, name, value);
            return DynamicGridUtils.UpdateEditorValue(_items, name, value);
        }

        private void Editor_OnEditorCreated(object sender, double height, double width)
        {
            var screen = WpfScreen.GetScreenFrom(new Point(Left, Top));

            double spareheight = 90;
            double sparewidth = 25;

            var desiredheight = height + spareheight;
            var desiredwidth = width + sparewidth;
            if (Pages != null)
                foreach (var page in Pages)
                {
                    if (desiredheight < page.MinimumSize().Height)
                        desiredheight = page.MinimumSize().Height;
                    if (desiredwidth < page.MinimumSize().Width)
                        desiredwidth = page.MinimumSize().Width;
                }

            var maxheight = screen.WorkingArea.Height - 0;
            Height = desiredheight > maxheight ? maxheight : desiredheight;

            var maxwidth = screen.WorkingArea.Width - 0;
            Width = desiredwidth > maxwidth ? maxwidth : desiredwidth;

            Left = screen.DeviceBounds.Left + (screen.DeviceBounds.Width - Width) / 2.0F;
            Top = screen.DeviceBounds.Top + (screen.DeviceBounds.Height - Height) / 2.0F;

            Editor.VerticalAlignment = VerticalAlignment.Stretch;
            Editor.HorizontalAlignment = HorizontalAlignment.Stretch;

            var scaption = _items[0].GetType().GetCaption();
            Title = "Edit " + scaption.SplitCamelCase();
            if (Editor.IsCustomLayout)
                Title = Title + "*";

            OKButton.IsEnabled = !ReadOnly;
        }
        
        private DynamicGridColumns Editor_OnCustomiseColumns(object sender, DynamicGridColumns? source)
        {
            var columns = new DynamicGridColumns();
            if (_items != null && _items.Any())
                columns.ExtractColumns(_items.First().GetType(), "");
            if (OnCustomiseColumns != null)
                columns = OnCustomiseColumns.Invoke(this, columns);
            return columns;
        }

        private void Btn_Click(object sender, RoutedEventArgs e)
        {
            var button = (Button)sender;
            var deb = (DynamicEditorButton)button.Tag;
            deb.Click();
        }

        private void OKButton_Click(object sender, RoutedEventArgs e)
        {
            var errors = OnValidateData?.Invoke(this, Items);

            if (errors != null && errors.Any())
            {
                MessageBox.Show(
                    string.Format("The following errors have been found with your data!\nPlease correct them and try again.\n\n- {0}",
                        string.Join("\n- ", errors)), "Validation Error");
                return;
            }

            // Don't Commit the changes here, because we want to refer back to thos changes when we save the item
            // to trigger specific processes in the database
            DialogResult = true;
            //Close();
        }

        private void CancelButton_Click(object sender, RoutedEventArgs e)
        {
            // However, if we cancel the edits, then we can safely revert the items back to their original (loaded) state
            foreach (var item in _items)
                item.CancelChanges();
            DialogResult = false;
            //Close();
        }

        public bool TryFindEditor(string columnname, [NotNullWhen(true)] out IDynamicEditorControl? editor)
        {
            return Editor.TryFindEditor(columnname, out editor);
        }
        public IDynamicEditorControl? FindEditor(string columnname)
        {
            return Editor.FindEditor(columnname);
        }

        private void Window_Closing(object sender, CancelEventArgs e)
        {
            if (DialogResult == true)
                OnSaveItem?.Invoke(this, e);
        }

        #region Win32 API Stuff

        // Define the Win32 API methods we are going to use
        [DllImport("user32.dll")]
        private static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);

        [DllImport("user32.dll")]
        private static extern bool InsertMenu(IntPtr hMenu, int wPosition, int wFlags, int wIDNewItem, string lpNewItem);

        /// Define our Constants we will use
        public const int WM_SYSCOMMAND = 0x112;

        public const int MF_SEPARATOR = 0x800;
        public const int MF_BYPOSITION = 0x400;
        public const int MF_STRING = 0x0;

        public const int _EditLayoutID = 1000;
        public const int _ResetLayoutID = 1001;

        public IntPtr Handle => new WindowInteropHelper(this).Handle;

        private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
        {
            // Check if a System Command has been executed
            if (msg == WM_SYSCOMMAND)
                // Execute the appropriate code for the System Menu item that was clicked
                switch (wParam.ToInt32())
                {
                    case _EditLayoutID:
                        Editor.EditLayout();
                        handled = true;
                        break;
                    case _ResetLayoutID:
                        if (MessageBox.Show(
                                "WARNING: This will delete any customisations you have made!\n\nAre you sure you wish to reset this layout?",
                                "Confirm Layout Reset", MessageBoxButton.OKCancel) == MessageBoxResult.OK)
                            Editor.ResetLayout();
                        handled = true;
                        break;
                }

            return IntPtr.Zero;
        }

        private void ConfigureSystemMenu(object sender, RoutedEventArgs e)
        {
            /// Get the Handle for the Forms System Menu
            var systemMenuHandle = GetSystemMenu(Handle, false);

            /// Create our new System Menu items just before the Close menu item
            InsertMenu(systemMenuHandle, 5, MF_BYPOSITION | MF_SEPARATOR, 0, string.Empty); // <-- Add a menu seperator
            InsertMenu(systemMenuHandle, 6, MF_BYPOSITION, _EditLayoutID, "Edit Layout");
            InsertMenu(systemMenuHandle, 7, MF_BYPOSITION, _ResetLayoutID, "Reset Layout");

            // Attach our WndProc handler to this Window
            var source = HwndSource.FromHwnd(Handle);
            source.AddHook(WndProc);
        }

        #endregion

        //private void Wiki_Click(object sender, RoutedEventArgs e)
        //{
        //    System.Diagnostics.Process.Start("https://prs-software.com.au/wiki/index.php/" + CurrentPanelSlug());
        //}

        //private string CurrentPanelSlug()
        //{
        //    if ((Items != null) && Items.Any())
        //        return Items.First().GetType().EntityName().Split('.').Last();
        //    return "";
        //}
    }
}