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.Fingers;
using bbiwarg.Detectors.Palm;
using bbiwarg.Utility;
using bbiwarg.Graphics;

namespace bbiwarg.Detectors.Touch
{
    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>();
            float floodValueThreshold = 0.33f;

            foreach (Finger finger in fingers)
            {
                Vector2D tipPoint = finger.Tip;

                float floodValue = getFloodValue(tipPoint);
                if (floodValue > floodValueThreshold)
                {
                    //correct touchEvent position
                    Vector2D direction = finger.LineSegment.Line.Direction;
                    float directionFactor = 10;
                    float x = HelperFunctions.thresholdRange<float>(0, depthImage.Width - 1, tipPoint.X + directionFactor * direction.X);
                    float y = HelperFunctions.thresholdRange<float>(0, depthImage.Height - 1, tipPoint.Y + directionFactor * direction.Y);
                    Vector2D tep = new Vector2D(x, y);

                    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 searchSize = 15;
            int maxDepthDifference = 20;
            Int16 fingerDiameter = 5;
            Int16 depthAtTouch = (Int16)(depthImage.getDepthAt(touchPoint) + fingerDiameter);

            int minX = Math.Max(touchPoint.X - searchSize, 0);
            int maxX = Math.Min(touchPoint.X + searchSize, depthImage.Width);
            int minY = Math.Max(touchPoint.Y - searchSize, 0);
            int maxY = Math.Min(touchPoint.Y + searchSize, depthImage.Height);

            int matchedPixels = 0;
            int countedPixels = 0;
            for (int x = minX; x < maxX; x++)
            {
                for (int y = minY; y < maxY; y++)
                {
                    Int16 depth = depthImage.getDepthAt(x, y);
                    Color color = outputImage.getColotAt(x, y);
                    Color subtractColor;
                    if (depthAtTouch < depth && Math.Abs(depthAtTouch - depth) < maxDepthDifference)
                    {
                        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;

            //status bar (% of matched pixels) -> green
            for (int x = minX; x < minX + (maxX - minX) * rel; x++)
            {
                outputImage.drawPixel(x, maxY - 1, Constants.TouchEventStatusBarColor);
            }

            return rel;
        }
    }
}