using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Windows.Media;

using System.Windows;



namespace Microsoft.Research.DynamicDataDisplay.Charts.Shapes

{

	/// <summary>

	/// Represents a line in viewport space, coming through given points.

	/// </summary>

	public class ViewportLine : ViewportShape

	{

		private LineGeometry lineGeometry = new LineGeometry();



		/// <summary>

		/// Initializes a new instance of the <see cref="ViewportLine"/> class.

		/// </summary>

		public ViewportLine() { }



		#region Properties



		#region Point1 property



		/// <summary>

		/// Gets or sets the first point. It is a DependencyProperty.

		/// </summary>

		/// <value>The point1.</value>

		public Point Point1

		{

			get { return (Point)GetValue(Point1Property); }

			set { SetValue(Point1Property, value); }

		}



		public static readonly DependencyProperty Point1Property = DependencyProperty.Register(

		  "Point1",

		  typeof(Point),

		  typeof(ViewportLine),

		  new FrameworkPropertyMetadata(new Point(0, 0), OnPointReplaced));



		private static void OnPointReplaced(DependencyObject d, DependencyPropertyChangedEventArgs e)

		{

			ViewportLine owner = (ViewportLine)d;

			owner.UpdateUIRepresentation();

		}



		#endregion



		#region Point2 property



		/// <summary>

		/// Gets or sets the second point. It is a DependencyProperty.

		/// </summary>

		/// <value>The point2.</value>

		public Point Point2

		{

			get { return (Point)GetValue(Point2Property); }

			set { SetValue(Point2Property, value); }

		}



		public static readonly DependencyProperty Point2Property = DependencyProperty.Register(

		  "Point2",

		  typeof(Point),

		  typeof(ViewportLine),

		  new FrameworkPropertyMetadata(new Point(1, 1), OnPointReplaced));



		#endregion



		#endregion



		protected override void UpdateUIRepresentationCore()

		{

			base.UpdateUIRepresentationCore();



			Viewport2D viewport = Plotter.Viewport;

			double deltaX = Point1.X - Point2.X;

			double deltaY = Point1.Y - Point2.Y;

			double m = deltaY / deltaX;

			double b = Point1.Y - Point1.X * deltaY / deltaX;



			Func<double, double> func = x => m * x + b;



			double xMin = viewport.Visible.XMin;

			double xMax = viewport.Visible.XMax;

			Point p1 = new Point(xMin, func(xMin)).DataToScreen(viewport.Transform);

			Point p2 = new Point(xMax, func(xMax)).DataToScreen(viewport.Transform);



			lineGeometry.StartPoint = p1;

			lineGeometry.EndPoint = p2;

		}



		protected override Geometry DefiningGeometry

		{

			get { return lineGeometry; }

		}

	}

}