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;

namespace bbiwarg.Detectors.Touch
{
    class TouchDetector
    {
        private DepthImage depthImage;
        private TouchImage touchImage;
        private List<Finger> fingers;
        private List<TouchEvent> touchEvents;

        public TouchDetector(List<Finger> fingers, DepthImage depthImage, TouchImage touchImage) {
            this.depthImage = depthImage;
            this.touchImage = touchImage;
            this.fingers = fingers;
            this.touchEvents = new List<TouchEvent>();
            float floodValueThreshold = 0.5f;

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

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

                    touchImage.setTouchAt(tep.IntX, tep.IntY, TouchImageState.touchDetected);
                    TouchEvent touchEvent = new TouchEvent(tep, floodValue, finger);
                    touchEvents.Add(touchEvent);
                }
            }
        }

        public List<TouchEvent> getTouchEvents() {
            return touchEvents;
        }

        private float getFloodValue(int touchX, int touchY) {
            int searchSize = 15;
            int maxDepthDifference = 20;
            Int16 fingerDiameter = 5;
            Int16 depthAtTouch = (Int16) (depthImage.getDepthAt(touchX, touchY) + fingerDiameter);

            int minX = Math.Max(touchX - searchSize, 0);
            int maxX = Math.Min(touchX + searchSize, depthImage.getWidth());
            int minY = Math.Max(touchY - searchSize, 0);
            int maxY = Math.Min(touchY + searchSize, depthImage.getHeight());

            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);
                    touchImage.setTouchAt(x, y, TouchImageState.touchArea);
                    if (Math.Abs(depthAtTouch - depth) < maxDepthDifference) {
                        matchedPixels++;
                        touchImage.setTouchAt(x, y, TouchImageState.touchAreaMatched);
                    }
                    countedPixels++;
                }
            }

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

            //status bar (% of matched pixels) -> green
            for (int x = minX; x < minX + (maxX-minX)*rel; x++) {
                touchImage.setTouchAt(x, maxY - 1, TouchImageState.touchAreaStatusBar);
            }

                return rel;
        }
    }
}