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

namespace ONIX.Control
{
    [StyleTypedProperty(Property = "WatermarkStyle", StyleTargetType = typeof(TextBlock))]
    public class WatermarkTextBox : TextBox
    {

        static WatermarkTextBox()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(WatermarkTextBox), new FrameworkPropertyMetadata(typeof(WatermarkTextBox)));
        }


        public string Watermark
        {

            get { return (string)GetValue(WatermarkProperty); }
            set { SetValue(WatermarkProperty, value); }

        }

        public Style WatermarkStyle
        {

            get { return (Style)GetValue(WatermarkStyleProperty); }
            set { SetValue(WatermarkStyleProperty, value); }

        }


        public static Style GetWatermarkStyle(DependencyObject obj)
        {
            return (Style)obj.GetValue(WatermarkStyleProperty);
        }


        public static void SetWatermarkStyle(DependencyObject obj, Style value)
        {
            obj.SetValue(WatermarkStyleProperty, value);
        }

        public static readonly DependencyProperty WatermarkStyleProperty =
                DependencyProperty.RegisterAttached("WatermarkStyle", typeof(Style), typeof(WatermarkTextBox));



        public static string GetWatermark(DependencyObject obj)
        {
            return (string)obj.GetValue(WatermarkProperty);
        }

        public static void SetWatermark(DependencyObject obj, string value)
        {
            obj.SetValue(WatermarkProperty, value);
        }

       public static readonly DependencyProperty WatermarkProperty =
       DependencyProperty.RegisterAttached("Watermark", typeof(string), typeof(WatermarkTextBox),
       new FrameworkPropertyMetadata(OnWatermarkChanged));

        private static void OnWatermarkChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
        {

            PasswordBox pwdBox = sender as PasswordBox;

            if (pwdBox == null)
            {
                return;
            }

            pwdBox.PasswordChanged -= OnPasswordChanged;
            pwdBox.PasswordChanged += OnPasswordChanged;

            pwdBox.GotFocus -= pwdBox_GotFocus;
            pwdBox.GotFocus += pwdBox_GotFocus;

            pwdBox.LostFocus -= pwdBox_LostFocus;
            pwdBox.LostFocus += pwdBox_LostFocus;
        }

        static void pwdBox_LostFocus(object sender, RoutedEventArgs e)
        {
            PasswordBox pwdBox = sender as PasswordBox;
            TextBlock watermarkTextBlock = pwdBox.Template.FindName("WatermarkTextBlock", pwdBox) as TextBlock;
            if (pwdBox.SecurePassword.Length == 0)
            {
                watermarkTextBlock.Visibility = Visibility.Visible;
            }

        }

        static void pwdBox_GotFocus(object sender, RoutedEventArgs e)
        {
            PasswordBox pwdBox = sender as PasswordBox;
            TextBlock watermarkTextBlock = pwdBox.Template.FindName("WatermarkTextBlock", pwdBox) as TextBlock;
            if (pwdBox.SecurePassword.Length > 0)
            {
                watermarkTextBlock.Visibility = Visibility.Hidden;
            }
        }

        private static void OnPasswordChanged(object sender, RoutedEventArgs e)
        {

            PasswordBox pwdBox = sender as PasswordBox;
            TextBlock watermarkTextBlock = pwdBox.Template.FindName("WatermarkTextBlock", pwdBox) as TextBlock;

            if (watermarkTextBlock != null)
            {
                if (pwdBox.SecurePassword.Length == 0)
                {
                    watermarkTextBlock.Visibility = Visibility.Visible;
                }
                else
                {
                    watermarkTextBlock.Visibility = Visibility.Hidden;
                }
            }
        }

    }
}