using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Emgu.CV;
using Emgu.CV.Structure;
using bbiwarg.Images;
using bbiwarg.Detectors.FingerDetection;
using bbiwarg.Detectors.PalmDetection;
using bbiwarg.Utility;
using bbiwarg.Graphics;

namespace bbiwarg.Detectors.TouchDetection
{
    class TouchDetector
    {
        private DepthImage depthImage;
        private OutputImage outputImage;
        private List<Finger> fingers;
        public List<TouchEvent> TouchEvents { get; private set; }

        public TouchDetector(List<Finger> fingers, DepthImage depthImage, OutputImage outputImage)
        {
            this.depthImage = depthImage;
            this.outputImage = outputImage;
            this.fingers = fingers;
            this.TouchEvents = new List<TouchEvent>();

            foreach (Finger finger in fingers)
            {
                Vector2D tipPoint = finger.TipPoint;
                outputImage.fillCircle(tipPoint.IntX, tipPoint.IntY, 3, Constants.TouchEventTipColor);

                float floodValue = getFloodValue(tipPoint);
                if (floodValue > Constants.TouchEventMinFloodValue)
                {
                    //correct touchEvent position
                    Vector2D direction = finger.Direction;
                    Vector2D tep = (tipPoint + Constants.TouchEventTipCorrectionFactor * direction.getInverse()).moveInBound(Vector2D.Zero, depthImage.BottomRight, direction);

                    outputImage.fillCircle(tep.IntX, tep.IntY, 5, Constants.TouchEventDetectedColor);
                    TouchEvent touchEvent = new TouchEvent(tep, floodValue, finger);
                    TouchEvents.Add(touchEvent);
                }
            }
        }

        private float getFloodValue(Point touchPoint)
        {
            int minX = Math.Max(touchPoint.X - 2*Constants.TouchEventAreaSize / 3, 0);
            int maxX = Math.Min(touchPoint.X + Constants.TouchEventAreaSize / 3, depthImage.Width-1);
            int minY = Math.Max(touchPoint.Y - 2*Constants.TouchEventAreaSize / 3, 0);
            int maxY = Math.Min(touchPoint.Y + Constants.TouchEventAreaSize / 3, depthImage.Height-1);


            Vector2D relTouch = new Vector2D(touchPoint.X - minX, touchPoint.Y - minY);
            Rectangle rect = new Rectangle(minX, minY, maxX - minX + 1, maxY - minY + 1);
            Image<Gray, byte> touchArea = depthImage.Image.Copy(rect);

            MCvConnectedComp comp = new MCvConnectedComp();
            CvInvoke.cvFloodFill(touchArea, relTouch, new MCvScalar(255), new MCvScalar(0), new MCvScalar(2), out comp, Emgu.CV.CvEnum.CONNECTIVITY.EIGHT_CONNECTED, Emgu.CV.CvEnum.FLOODFILL_FLAG.DEFAULT, IntPtr.Zero);

            int matchedPixels = 0;
            int countedPixels = 0;
            for (int x = minX; x <= maxX; x++)
            {
                for (int y = minY; y <= maxY; y++)
                {
                    Color color = outputImage.getColotAt(x, y);
                    byte depth = touchArea.Data[y - minY, x - minX, 0];
                    Color subtractColor;
                    if(depth == 255)
                    {
                        matchedPixels++;
                        subtractColor = Constants.TouchEventAreaMatchedSubtractColor;
                    }
                    else
                    {
                        subtractColor = Constants.TouchEventAreaNonMatchedSubtractColor;
                    }
                    Color newColor = Color.FromArgb(Math.Max(color.R - subtractColor.R, 0), Math.Max(color.G - subtractColor.G, 0), Math.Max(color.B - subtractColor.B, 0));
                    outputImage.drawPixel(x, y, newColor);
                    countedPixels++;
                }
            }

            float rel = (float)matchedPixels / (float)countedPixels;

            outputImage.drawLineSegment(new Utility.LineSegment2D(new Vector2D(minX, maxY), new Vector2D(minX + rel * Constants.TouchEventAreaSize, maxY)), Constants.TouchEventStatusBarColor);
            outputImage.drawLineSegment(new Utility.LineSegment2D(new Vector2D(minX, maxY-1), new Vector2D(minX + rel * Constants.TouchEventAreaSize, maxY-1)), Constants.TouchEventStatusBarColor);
            
            return rel;
        }
    }
}