// Copyright (c) 2017 schick Informatik
// Description: DataGrid mit etwas "verbesserten" Funktionen
//

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;

using System.Windows.Controls.Primitives;
using System.Collections.Generic;

using System.Globalization;
using System.Threading;

namespace BreCalClient
{
    /// <summary>
    /// Follow steps 1a or 1b and then 2 to use this custom control in a XAML file.
    ///
    /// Step 1a) Using this custom control in a XAML file that exists in the current project.
    /// Add this XmlNamespace attribute to the root element of the markup file where it is 
    /// to be used:
    ///
    ///     xmlns:enictrl="clr-namespace:ENI2.Controls"
    ///
    ///
    /// Step 1b) Using this custom control in a XAML file that exists in a different project.
    /// Add this XmlNamespace attribute to the root element of the markup file where it is 
    /// to be used:
    ///
    ///     xmlns:enictrl="clr-namespace:ENI2.Controls;assembly=ENI2.Controls"
    ///
    /// You will also need to add a project reference from the project where the XAML file lives
    /// to this project and Rebuild to avoid compilation errors:
    ///
    ///     Right click on the target project in the Solution Explorer and
    ///     "Add Reference"->"Projects"->[Browse to and select this project]
    ///
    ///
    /// Step 2)
    /// Go ahead and use your control in the XAML file.
    ///
    ///     <MyNamespace:ENIDataGrid/>
    ///
    /// </summary>
    public class ENIDataGrid : DataGrid
    {        

        public event Action<object>? EditRequested;
        public event Action<object>? DeleteRequested;
        public event Action? CreateRequested;
        public event Action? RefreshGrid;

        public event Action<object>? PrintRequested;
        public event Action<object>? ExportRequested;
        public event Action<object>? ShowTextRequested;

        public void Initialize()
        {

            this.MouseDoubleClick += dataGrid_MouseDoubleClick;
            this.PreviewKeyDown += ENIDataGrid_PreviewKeyDown;

            this.ContextMenu = new ContextMenu();
            this.CanUserAddRows = false;
            this.IsReadOnly = false;

            MenuItem addItem = new MenuItem();

            addItem.Header = BreCalClient.Resources.Resources.textAdd;
            addItem.Icon = new Image { Source = Util.LoadImage(BreCalClient.Resources.Resources.add) };
            addItem.Click += new RoutedEventHandler(this.addItem);            
            this.ContextMenu.Items.Add(addItem);

            MenuItem deleteItem = new MenuItem();
            deleteItem.Header = BreCalClient.Resources.Resources.textDelete;
            deleteItem.Icon = new Image { Source = Util.LoadImage(BreCalClient.Resources.Resources.delete) };
            deleteItem.Click += this.deleteItem;
            this.ContextMenu.Items.Add(deleteItem);

            MenuItem editItem = new MenuItem();
            editItem.Header = BreCalClient.Resources.Resources.textEdit;
            editItem.Icon = new Image { Source = Util.LoadImage(BreCalClient.Resources.Resources.edit) };
            editItem.Click += this.editItem;
            this.ContextMenu.Items.Add(editItem);            
        }

        private void ENIDataGrid_PreviewKeyDown(object sender, KeyEventArgs e)
        {
            if(sender is ENIDataGrid)
            {
                var grid = sender as ENIDataGrid;
                if (Key.Delete == e.Key)
                    this.deleteItem(null, null);
            }
        }

        #region public

        public DataGridRow GetRow(int index)
        {
            DataGridRow row = (DataGridRow)this.ItemContainerGenerator.ContainerFromIndex(index);
            if(row == null)
            {
                this.UpdateLayout();
                this.ScrollIntoView(this.Items[index]);
                row = (DataGridRow)this.ItemContainerGenerator.ContainerFromIndex(index);
            }
            return row;
        }

        public DataGridCell? GetCell(DataGridRow row, int column)
        {
            if (row != null)
            {
                DataGridCellsPresenter? presenter = GetVisualChild<DataGridCellsPresenter>(row);

                if (presenter == null)
                {
                    this.ScrollIntoView(row, this.Columns[column]);
                    presenter = GetVisualChild<DataGridCellsPresenter>(row);
                }

                DataGridCell? cell = (DataGridCell?)presenter?.ItemContainerGenerator.ContainerFromIndex(column);
                return cell;
            }
            return null;
        }

        public DataGridCell? GetCell(int rowIndex, int columnIndex)
        {
            DataGridRow row = this.GetRow(rowIndex);
            return this.GetCell(row, columnIndex);
        }

        #endregion

        #region protected

        protected void addItem(object sender, RoutedEventArgs e)
        {            
            if (!this.IsReadOnly)
            {
                this.CreateRequested?.Invoke();
            }
            e.Handled = true;
        }

        protected void deleteItem(object? sender, RoutedEventArgs? e)
        {
            if((this.SelectedItems != null) && (this.SelectedItems.Count > 0) && !this.IsReadOnly)
            {
                MessageBoxResult result = MessageBox.Show("Are your sure?", "Please confirm", MessageBoxButton.YesNo, MessageBoxImage.Question);
                if (result == MessageBoxResult.Yes)
                {
                    List<object> deleteList = new List<object>();
                    foreach (object deleteItem in this.SelectedItems)
                        deleteList.Add(deleteItem);

                    foreach (object deleteItem in deleteList)
                    {
                        if (deleteItem != null)
                        {
                            this.DeleteRequested?.Invoke(deleteItem);
                        }
                    }

                    this.RefreshGrid?.Invoke();

                }
            }
        }        

        protected void editItem(object sender, RoutedEventArgs e)
        {
            if((this.SelectedItems != null) && (this.SelectedItems.Count == 1) && !this.IsReadOnly)
            {
                if (this.SelectedItems[0] is object selectedEntity)
                    this.EditRequested?.Invoke(selectedEntity);
            }
        }

        protected void printItem(object sender, RoutedEventArgs e)
        {
            if ((this.SelectedItems != null) && (this.SelectedItems.Count == 1) )
            {
                if (this.SelectedItems[0] is object selectedEntity)
                    this.PrintRequested?.Invoke(selectedEntity);
            }
        }

        protected void exportItem(object sender, RoutedEventArgs e)
        {
            if ((this.SelectedItems != null) && (this.SelectedItems.Count == 1))
            {
                if (this.SelectedItems[0] is object selectedEntity)
                    this.ExportRequested?.Invoke(selectedEntity);
            }
        }

        protected void showTextItem(object sender, RoutedEventArgs e)
        {
            if ((this.SelectedItems != null) && (this.SelectedItems.Count == 1))
            {
                if (this.SelectedItems[0] is object selectedEntity)
                    this.ShowTextRequested?.Invoke(selectedEntity);
            }
        }

        #endregion

        #region private

        private void dataGrid_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            if (sender != null)
            {
                if ((sender is DataGrid grid) && (grid.SelectedItems != null) && (grid.SelectedItems.Count == 1) && !this.IsReadOnly)
                {
                    DataGridRow? dgr = grid.ItemContainerGenerator.ContainerFromItem(grid.SelectedItem) as DataGridRow;
                    if (grid.SelectedItem is object selectedEntity)
                        this.EditRequested?.Invoke(selectedEntity);
                }
            }
        }

        #endregion

        #region private static

        private static T? GetVisualChild<T>(Visual parent) where T : Visual
        {
            T? child = default;
            int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
            for (int i = 0; i < numVisuals; i++)
            {
                Visual? v = (Visual)VisualTreeHelper.GetChild(parent, i);
                child = v as T;
                if (child == null)
                {
                    child = GetVisualChild<T>(v);
                }
                if (child != null)
                {
                    break;
                }
            }
            return child;
        }

        #endregion

    }
}