using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Markup;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace Tango.SharedUI.Controls
{
    [ContentProperty(nameof(Text))]
    public class FastTextBlock : Control
    {
        private FormattedText _formattedText;

        static FastTextBlock()
        {

        }

        public FastTextBlock()
        {
            Loaded += FastTextBlock_Loaded;
        }

        private void FastTextBlock_Loaded(object sender, RoutedEventArgs e)
        {
            Init();
        }

        public static readonly DependencyProperty TextProperty =
             DependencyProperty.Register(
                 "Text",
                 typeof(string),
                 typeof(FastTextBlock),
                 new FrameworkPropertyMetadata(string.Empty, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender,
                    (o, e) => ((FastTextBlock)o).TextPropertyChanged((string)e.NewValue)));

        private void TextPropertyChanged(string text)
        {
            Init();
        }

        private void Init()
        {
            if (Text != null)
            {
                var typeface = new Typeface(
                    FontFamily,
                    FontStyle, FontWeight, FontStretch);

                _formattedText = new FormattedText(
                    Text, CultureInfo.CurrentCulture,
                    FlowDirection.LeftToRight, typeface, FontSize, Foreground);
            }
        }


        public string Text
        {
            get { return (string)GetValue(TextProperty); }
            set { SetValue(TextProperty, value); }
        }

        protected override void OnRender(DrawingContext drawingContext)
        {
            if (_formattedText != null)
            {
                drawingContext.DrawText(_formattedText, new Point());
            }
        }

        protected override Size MeasureOverride(Size constraint)
        {
            return _formattedText != null
            ? new Size(_formattedText.Width, _formattedText.Height)
            : new Size();
        }
    }
}