using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;

namespace TradeIdeas.TIProGUI.EnhancedSingleStockWindow
{
    //The  PreviewTexInput event handlers for the WPF combobox were not working as desired and instead gave weird anomalies such as converting a character to
    // uppercase yet keeping the previous character unchanges. So, found this code from the following reference:
    // https://stackoverflow.com/questions/3945221/wpf-combobox-with-forced-uppercase
    // https://social.msdn.microsoft.com/Forums/vstudio/en-US/4b963ae7-5032-4856-88a1-32256e664d4d/wpf-combobox-charactercasing?forum=wpf
    //
    public static class WPFComboAllCaps
    {
        [AttachedPropertyBrowsableForType(typeof(ComboBox))]
        public static CharacterCasing GetCharacterCasing(ComboBox comboBox)
        {
            return (CharacterCasing)comboBox.GetValue(CharacterCasingProperty);
        }

        public static void SetCharacterCasing(ComboBox comboBox, CharacterCasing value)
        {
            comboBox.SetValue(CharacterCasingProperty, value);
        }

        // Using a DependencyProperty as the backing store for CharacterCasing.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty CharacterCasingProperty =
            DependencyProperty.RegisterAttached(
                "CharacterCasing",
                typeof(CharacterCasing),
                typeof(WPFComboAllCaps),
                new UIPropertyMetadata(
                    CharacterCasing.Normal,
                    OnCharacterCasingChanged));

        private static void OnCharacterCasingChanged(DependencyObject o, DependencyPropertyChangedEventArgs e)
        {
            var comboBox = o as ComboBox;
            if (comboBox == null)
                return;

            if (comboBox.IsLoaded)
            {
                ApplyCharacterCasing(comboBox);
            }
            else
            {
                // To avoid multiple event subscription
                comboBox.Loaded -= new RoutedEventHandler(comboBox_Loaded);
                comboBox.Loaded += new RoutedEventHandler(comboBox_Loaded);
            }
        }

        private static void comboBox_Loaded(object sender, RoutedEventArgs e)
        {
            var comboBox = sender as ComboBox;
            if (comboBox == null)
                return;

            ApplyCharacterCasing(comboBox);
            //comboBox.Loaded -= comboBox_Loaded; //commented out (as per reply in second link mentioned in the top comments.
        }

        private static void ApplyCharacterCasing(ComboBox comboBox)
        {
            var textBox = comboBox.Template.FindName("PART_EditableTextBox", comboBox) as TextBox;
            if (textBox != null)
            {
                textBox.CharacterCasing = GetCharacterCasing(comboBox);
            }
        }
    }
}