using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Windows;

using Microsoft.Research.DynamicDataDisplay.Common.Auxiliary;

using Microsoft.Research.DynamicDataDisplay.DataSources;

using DataSource = Microsoft.Research.DynamicDataDisplay.DataSources.INonUniformDataSource2D<System.Windows.Vector>;

using System.Windows.Media.Imaging;

using System.Windows.Media;

using Microsoft.Research.DynamicDataDisplay.Maps.Charts.VectorFields;

using Microsoft.Research.DynamicDataDisplay.Charts.Isolines;

using System.Threading;

using System.Windows.Controls;

using System.Threading.Tasks;

using System.Windows.Threading;

using Microsoft.Research.DynamicDataDisplay.Common.Palettes;

using Microsoft.Research.DynamicDataDisplay.Charts;



namespace Microsoft.Research.DynamicDataDisplay.Maps.Charts

{

	public class VectorFieldConvolutionChart : Image

	{

		public VectorFieldConvolutionChart()

		{

			Stretch = Stretch.Fill;

		}



		#region Properties



		public DataSource DataSource

		{

			get { return (DataSource)GetValue(DataSourceProperty); }

			set { SetValue(DataSourceProperty, value); }

		}



		public static readonly DependencyProperty DataSourceProperty = DependencyProperty.Register(

		  "DataSource",

		  typeof(DataSource),

		  typeof(VectorFieldConvolutionChart),

		  new FrameworkPropertyMetadata(null, OnDataSourceReplaced));



		private static void OnDataSourceReplaced(DependencyObject d, DependencyPropertyChangedEventArgs e)

		{

			VectorFieldConvolutionChart owner = (VectorFieldConvolutionChart)d;

			owner.OnDataSourceReplaced((DataSource)e.OldValue, (DataSource)e.NewValue);

		}



		private void OnDataSourceReplaced(IDataSource2D<Vector> prevDataSource, IDataSource2D<Vector> currDataSource)

		{

			var dataSource = this.GetValueSync<IDataSource2D<Vector>>(DataSourceProperty);

			var contentBounds = dataSource.Grid.GetGridBounds();

			if (Parent != null)

				Viewport2D.SetContentBounds(Parent, contentBounds);

			ViewportPanel.SetViewportBounds(this, contentBounds);



			int width = currDataSource.Width;

			int height = currDataSource.Height;

			bmp = new WriteableBitmap(width, height, 96, 96, PixelFormats.Pbgra32, null);

			Source = bmp;



			Task task = new Task(() => CreateConvolutionBmp(width, height));

			task.Start();

		}



		#endregion // end of Properties



		WriteableBitmap bmp;



		private void UpdateBitmap(int[] pixels)

		{

			bmp.Dispatcher.BeginInvoke(() =>

			{

				int width = (int)bmp.Width;

				int height = (int)bmp.Height;

				bmp.WritePixels(new Int32Rect(0, 0, width, height), pixels, (width * bmp.Format.BitsPerPixel + 7) / 8, 0);

			});

		}





		private readonly NormalizeFilter normalizeFilter = new NormalizeFilter();

		public NormalizeFilter NormalizeFilter

		{

			get { return normalizeFilter; }

		}



		private readonly MagnitudeFilter magnitudeFilter = new MagnitudeFilter { Palette = new UniformLinearPalette(Colors.Green, Colors.GreenYellow, Colors.Red) };

		public MagnitudeFilter MagnitudeFilter

		{

			get { return magnitudeFilter; }

		}



		private void CreateConvolutionBmp(int width, int height)

		{

			int[] pixels = new int[width * height];



			var dataSource = this.GetValueSync<IDataSource2D<Vector>>(DataSourceProperty); ;

			GenerateWhiteNoizeImage(width, height, pixels);

			//GenerateWhiteCirclesImage(width, height, pixels);



			UpdateBitmap(pixels);



			int[] effectivePixels = CreateConvolutionArray(width, height, pixels);



			UpdateBitmap(effectivePixels);



			normalizeFilter.ApplyFilter(effectivePixels, width, height, dataSource.Data);



			magnitudeFilter.ApplyFilter(effectivePixels, width, height, dataSource.Data);



			UpdateBitmap(effectivePixels);

		}



		private static void GenerateWhiteNoizeImage(int width, int height, int[] pixels)

		{

			Random rnd = new Random();

			for (int i = 0; i < width * height; i++)

			{

				HsbColor color = new HsbColor(0, 0, Math.Round(5 * rnd.NextDouble()) / 4);

				int argb = color.ToArgb();

				pixels[i] = argb;

			}

		}



		private static void GenerateWhiteCirclesImage(int width, int height, int[] pixels)

		{

			DrawingImage image = new DrawingImage();



			Random rnd = new Random();

			const double radius = 4;

			const int circlesNum = 100;



			DrawingGroup group = new DrawingGroup();

			var dc = group.Open();

			for (int i = 0; i < circlesNum; i++)

			{

				dc.DrawEllipse(Brushes.White, null, new Point(rnd.NextDouble() * width, rnd.NextDouble() * height), radius, radius);

			}

			dc.Close();



			image.Drawing = group;



			RenderTargetBitmap renderBmp = new RenderTargetBitmap(width, height, 96, 96, PixelFormats.Pbgra32);

			renderBmp.Render(new Image { Source = image });



			renderBmp.CopyPixels(pixels, (width * renderBmp.Format.BitsPerPixel + 7) / 8, 0);

		}



		private int[] CreateConvolutionArray(int width, int height, int[] pixels)

		{

			var dataSource = this.GetValueSync<DataSource>(DataSourceProperty); ;



			const int Length = 20;

			const int maxIterations = 20;



			int pixelsCount = width * height;

			int[] effectivePixels = new int[pixelsCount];



			pixels.CopyTo(effectivePixels, 0);



			System.Threading.Tasks.Parallel.For(0, pixelsCount, i =>

			{

				if (i % 1000 == 0)

					UpdateBitmap(effectivePixels);



				int ix = i % width;

				int iy = i / width;



				double sumDistance = 1;

				double positiveDistance = 0;

				Point position = dataSource.Grid[ix, iy];

				ConvolutionColor color = ConvolutionColor.FromArgb(pixels[ix + width * iy]);



				int iterationsCounter = 0;

				do

				{

					int i_x = ix;

					int i_y = iy;

					iterationsCounter++;



					Vector vector =

						//GetVector(dataSource, new IntPoint(i_x, i_y), position); 

						dataSource.Data[i_x, i_y];



					if (vector.Length > 0)

						vector.Normalize();



					position += vector;

					positiveDistance += vector.Length;



					IntPoint coordinate;

					bool found = GetCoordinate(dataSource, position, out coordinate);

					if (found)

					{

						i_x = coordinate.X;

						i_y = coordinate.Y;

						var currentColor = ConvolutionColor.FromArgb(pixels[i_x + i_y * width]);

						color += currentColor;



						sumDistance += 1;

					}

					else

						break;

				}

				while (positiveDistance < Length && iterationsCounter < maxIterations);



				var negativeDistance = 0.0;

				iterationsCounter = 0;

				do

				{

					int i_x = ix;

					int i_y = iy;

					iterationsCounter++;



					Vector vector =

						//GetVector(dataSource, new IntPoint(i_x, i_y), position);

						 dataSource.Data[i_x, i_y];

					if (vector.Length > 0)

						vector.Normalize();



					position -= vector;

					negativeDistance += vector.Length;



					IntPoint coordinate;

					bool found = GetCoordinate(dataSource, position, out coordinate);

					if (found)

					{

						i_x = coordinate.X;

						i_y = coordinate.Y;

						var currentColor = ConvolutionColor.FromArgb(pixels[i_x + i_y * width]);

						color += currentColor;



						sumDistance += 1;

					}

					else

						break;

				}

				while (negativeDistance < Length && iterationsCounter < maxIterations);



				color /= sumDistance;

				effectivePixels[i] = color.ToArgb();

			});



			return effectivePixels;

		}



		private static ConvolutionColor GetColor(DataSource dataSource, int[] pixels, IntPoint coordinate, Point point)

		{

			int x = coordinate.X;

			int y = coordinate.Y;



			var x0 = dataSource.XCoordinates[x];

			var x1 = dataSource.XCoordinates[x + 1];



			var y0 = dataSource.YCoordinates[y];

			var y1 = dataSource.YCoordinates[y + 1];



			double xRatio = GetRatio(x0, x1, point.X);

			double yRatio = GetRatio(y0, y1, point.Y);



			int width = dataSource.Width;



			var v00 = pixels[x + y * width];

			var v01 = pixels[x + 1 + y * width];

			var v10 = pixels[x + (y + 1) * width];

			var v11 = pixels[x + 1 + (y + 1) * width];



			var result = (int)(((1 - xRatio) * v00 + xRatio * v10 +

							(1 - xRatio) * v01 + xRatio * v11 +

							(1 - yRatio) * v00 + yRatio * v01 +

							(1 - yRatio) * v10 + yRatio * v11) * 0.25);

			//var result = v00;



			return ConvolutionColor.FromArgb(result);

		}



		private static Vector GetVector(DataSource dataSource, IntPoint index, Point position)

		{

			int ix0 = index.X;

			int iy0 = index.Y;



			int ix1 = ix0 + 1 < dataSource.Width ? ix0 + 1 : ix0;

			int iy1 = iy0 + 1 < dataSource.Height ? iy0 + 1 : iy0;



			var x0 = dataSource.XCoordinates[ix0];

			var x1 = dataSource.XCoordinates[ix1];



			var y0 = dataSource.YCoordinates[iy0];

			var y1 = dataSource.YCoordinates[iy1];



			double xRatio = GetRatio(x0, x1, position.X);

			double yRatio = GetRatio(y0, y1, position.Y);



			Vector v00 = dataSource.Data[ix0, iy0];

			Vector v01 = dataSource.Data[ix0, iy1];

			Vector v10 = dataSource.Data[ix1, iy0];

			Vector v11 = dataSource.Data[ix1, iy1];



			Vector result = (1 - xRatio) * v00 + xRatio * v10 +

							(1 - xRatio) * v01 + xRatio * v11 +

							(1 - yRatio) * v00 + yRatio * v01 +

							(1 - yRatio) * v10 + yRatio * v11;



			result *= 0.25;



			return result;

		}



		private static double GetRatio(double a, double b, double x)

		{

			if (a != b)

				return (x - a) / (b - a);

			else

				return x;

		}



		private static bool GetCoordinate(DataSource dataSource, Point point, out IntPoint coordinate)

		{

			var ix = IndexOf(dataSource.XCoordinates, point.X);

			int iy = IndexOf(dataSource.YCoordinates, point.Y);



			coordinate = new IntPoint(ix, iy);



			return ix > -1 && iy > -1;

		}



		private static int IndexOf(double[] coordinates, double x)

		{

			int ix = -1;

			for (int i = 0; i < coordinates.Length - 1; i++)

			{

				if (coordinates[i + 1] >= x)

				{

					ix = i;

					break;

				}

			}



			return ix;

		}



		//#region IPlotterElement Members



		//Plotter2D plotter;

		//public void OnPlotterAttached(Plotter plotter)

		//{

		//    this.plotter = (Plotter2D)plotter;

		//    plotter.CentralGrid.Children.Add(this);

		//}



		//public void OnPlotterDetaching(Plotter plotter)

		//{

		//    plotter.CentralGrid.Children.Remove(this);

		//    this.plotter = null;

		//}



		//public Plotter Plotter

		//{

		//    get { return plotter; }

		//}



		//#endregion

	}

}