using Tool.Layout.ViewModels;
using System;
using System.Collections.Generic;
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.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using Tool.ViewModels;
using System.Collections.ObjectModel;

namespace Tool.Layout.Views
{
	public class ViewBase : UserControl
	{
		public ViewBase()
		{
			this.Loaded += ViewBase_Loaded;
			this.Unloaded += ViewBase_Unloaded;
			Dispatcher.ShutdownStarted += Dispatcher_ShutdownStarted;
		}

		void Dispatcher_ShutdownStarted(object sender, EventArgs e)
		{
			if (ViewModel != null)
			{
				ViewModel.RemoveView(this);
			}
		}

		protected virtual void ViewBase_Unloaded(object sender, RoutedEventArgs e)
		{
			if (ViewModel != null)
			{
				ViewModel.RemoveView(this);
			}
		}

		protected virtual void ViewBase_Loaded(object sender, RoutedEventArgs e)
		{
			if (ViewModel != null)
			{
				ViewModel.AddView(this);
			}
		}

		public static DependencyProperty LeafProperty = DependencyProperty.Register("Leaf", typeof(LeafViewModel), typeof(ViewBase), new FrameworkPropertyMetadata());
		public LeafViewModel Leaf
		{
			get
			{
				return GetValue(LeafProperty) as LeafViewModel;
			}
			set
			{
				SetValue(LeafProperty, value);
			}
		}

		public static readonly DependencyProperty ToolBarTemplateProperty = DependencyProperty.Register("ToolBarTemplate", typeof(ControlTemplate), typeof(LeafView), new FrameworkPropertyMetadata());
		public ControlTemplate ToolBarTemplate
		{
			get
			{
				return GetValue(ToolBarTemplateProperty) as ControlTemplate;
			}
			set
			{
				SetValue(ToolBarTemplateProperty, value);
			}
		}

		public ViewModelBase ViewModel
		{
			get
			{
				return this.DataContext as ViewModelBase;
			}
		}

		public static void DrawText(DrawingContext _context, Brush _brush, Point _point, string _sText, Brush _backgroundBrush = null, HorizontalAlignment _eHAlignment = HorizontalAlignment.Left, VerticalAlignment _eVAlignment = VerticalAlignment.Top)
		{
			var rect = new Rect(_point, new Size());
			DrawText(_context, _brush, ref rect, _sText, _backgroundBrush, _eHAlignment, _eVAlignment);
		}

		public static void DrawText(DrawingContext _context, Brush _brush, ref Rect _rect, string _sText, Brush _backgroundBrush = null, HorizontalAlignment _eHAlignment = HorizontalAlignment.Left, VerticalAlignment _eVAlignment = VerticalAlignment.Top)
		{
			if (string.IsNullOrWhiteSpace(_sText))
			{
				return;
			}

			var geo = CreateTextGeometry(_sText, 12.0, _rect.Location, _eHAlignment, _eVAlignment);
			if (_backgroundBrush != null)
			{
				_rect = new Rect(_rect.Location, new Size(Math.Max(_rect.Width, geo.Item2), Math.Max(_rect.Height, geo.Item3)));
				_context.DrawRectangle(_backgroundBrush, null, _rect);
			}
			_context.DrawGlyphRun(_brush, geo.Item1);
		}

		public static Tuple<GlyphRun, double, double> CreateTextGeometry(string _sText, double _fSize, Point _position, HorizontalAlignment _eHAlignment = HorizontalAlignment.Left, VerticalAlignment _eVAlignment = VerticalAlignment.Top)
		{
			if (s_GlyphTypeface == null)
			{
				Typeface typeface = new Typeface("Consolas");
				if (!typeface.TryGetGlyphTypeface(out s_GlyphTypeface))
				{
					throw new InvalidOperationException("No glyphtypeface found");
				}
			}

			var key = Tuple.Create(_sText, _fSize);
			Tuple<double, ushort[], double[]> cache;
			if (!s_dGlyphCache.TryGetValue(key, out cache))
			{
				var totalWidth = 0d;
				int n = 0;
				var aGlyphIndices = new ushort[_sText.Length];
				var aAdvanceWidths = new double[_sText.Length];
				for (; n < _sText.Length; n++)
				{
					ushort glyphIndex = s_GlyphTypeface.CharacterToGlyphMap[_sText[n]];

					var glyphWidth = s_aGlyphWidths[glyphIndex];
					if (glyphWidth == 0.0)
					{
						glyphWidth = s_GlyphTypeface.AdvanceWidths[glyphIndex] * _fSize;
						s_aGlyphWidths[glyphIndex] = glyphWidth;
					}

					aGlyphIndices[n] = glyphIndex;
					aAdvanceWidths[n] = glyphWidth;
					totalWidth += glyphWidth;
				}
				s_dGlyphCache[key] = cache = Tuple.Create(totalWidth, aGlyphIndices, aAdvanceWidths);
			}

			var offsetPosition = new Point(Math.Floor(_position.X), Math.Floor(_position.Y + _fSize));
			switch (_eHAlignment)
			{
				case HorizontalAlignment.Center: offsetPosition.X -= cache.Item1 * 0.5; break;
				case HorizontalAlignment.Right: offsetPosition.X -= cache.Item1; break;
			}
			switch (_eVAlignment)
			{
				case VerticalAlignment.Center: offsetPosition.Y -= _fSize * 0.5; break;
				case VerticalAlignment.Bottom: offsetPosition.Y -= _fSize; break;
			}

			var gr = new GlyphRun(s_GlyphTypeface, 0, false, _fSize, cache.Item2, offsetPosition, cache.Item3, null, null, null, null, null, null);
			return Tuple.Create(gr, cache.Item1, _fSize);
		}

		private static GlyphTypeface s_GlyphTypeface;
		private static Dictionary<Tuple<string, double>, Tuple<double, ushort[], double[]>> s_dGlyphCache = new Dictionary<Tuple<string, double>, Tuple<double, ushort[], double[]>>();
		private static double[] s_aGlyphWidths = new double[1024];
	}
}