using System;
using System.Collections.Generic;
using System.Drawing;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using bbiwarg.Recognition.TouchRecognition;
using bbiwarg.Utility;

namespace bbiwarg.Graphics
{
    class TouchEventVisualizer
    {
        public OutputImage OutputImage { get; private set; }

        private int width, height;
        private Stopwatch timer;

        private Dictionary<int, List<Vector2D>> currentPositions;
        private Dictionary<long, List<Vector2D>> oldPositions;


        public TouchEventVisualizer(int width, int height)
        {
            this.width = width;
            this.height = height;
            this.timer = new Stopwatch();
            this.currentPositions = new Dictionary<int, List<Vector2D>>();
            this.oldPositions = new Dictionary<long, List<Vector2D>>();

            this.timer.Start();
        }

        public void touchDown(object sender, PalmTouchEventArgs ptea)
        {
            List<Vector2D> posList = new List<Vector2D>();
            posList.Add(ptea.Position);
            currentPositions.Add(ptea.TrackID, posList);
        }


        public void touchMove(object sender, PalmTouchEventArgs ptea)
        {
            currentPositions[ptea.TrackID].Add(ptea.Position);
        }

        public void touchUp(object sender, PalmTouchEventArgs ptea)
        {
            currentPositions[ptea.TrackID].Add(ptea.Position);

            List<Vector2D> posList = currentPositions[ptea.TrackID];
            oldPositions.Add(timer.ElapsedMilliseconds, posList);

            currentPositions.Remove(ptea.TrackID);
        }

        public void updateImage()
        {
            //remove old positions
            long currentTime = timer.ElapsedMilliseconds;

            List<long> removeKeys = new List<long>();
            foreach (long lastUpdateTime in oldPositions.Keys)
            {
                if (currentTime - lastUpdateTime > Constants.TouchEventVisualizerFadeOutTime)
                    removeKeys.Add(lastUpdateTime);
            }
            foreach (long lastUpdateTime in removeKeys)
                oldPositions.Remove(lastUpdateTime);


            OutputImage = new OutputImage(width, height);

            //border
            OutputImage.drawRectangle(0, 0, width - 1, height - 1, Constants.TouchEventVisualizerGridColor);

            //draw grid
            int numRows = Constants.PalmGridNumRows;
            int numColumns = Constants.PalmGridNumColumns;
            int widthPerColumn = width / numColumns;
            int heightPerRow = height / numRows;

            for (int i = 0; i <= numColumns; i++)
            {
                OutputImage.drawLineSegment(new LineSegment2D(new Vector2D(i * widthPerColumn, 0), new Vector2D(i * widthPerColumn, height - 1)), Constants.TouchEventVisualizerGridColor);
            }

            for (int i = 0; i <= numRows; i++)
            {
                OutputImage.drawLineSegment(new LineSegment2D(new Vector2D(0, i * heightPerRow), new Vector2D(width - 1, i * heightPerRow)), Constants.TouchEventVisualizerGridColor);
            }

            foreach (int id in currentPositions.Keys)
                drawTouchGesture(currentPositions[id], 1);
            foreach (long lastUpdate in oldPositions.Keys)
                drawTouchGesture(oldPositions[lastUpdate], 1 - ((currentTime - lastUpdate) / (float)Constants.TouchEventVisualizerFadeOutTime));

        }

        public void drawTouchGesture(List<Vector2D> positions, float opacity)
        {
            Vector2D maxPixel = new Vector2D(width - 1, height - 1);
            int numPositions = positions.Count; 
            Color lineColor = Constants.TouchEventVisualizerLineColor;
            Color pointColor = Constants.TouchEventVisualizerPointColor;
            Color lineColorFaded = Color.FromArgb((int)(opacity * lineColor.R), (int)(opacity * lineColor.G), (int)(opacity * lineColor.B));
            Color pointColorFaded = Color.FromArgb((int)(opacity * pointColor.R), (int)(opacity * pointColor.G), (int)(opacity * pointColor.B));
            for (int i = 1; i < numPositions; i++)
            {
                OutputImage.drawLineSegment(new LineSegment2D(positions[i - 1].scale(maxPixel), positions[i].scale(maxPixel)), lineColorFaded);
            }
            Vector2D lastPos = positions[numPositions - 1].scale(maxPixel);
            OutputImage.fillCircle(lastPos.IntX, lastPos.IntY, 3, pointColorFaded);
        }

        public void reset()
        {
            OutputImage = new OutputImage(width, height);
            currentPositions.Clear();
        }
    }
}