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, int> idTranslations;
        private Dictionary<int, List<Vector2D>> positions;
        private Dictionary<int, long> lastUpdates;
        private int nextFreeID;


        public TouchEventVisualizer(int width, int height)
        {
            this.width = width;
            this.height = height;
            reset();

        }

        public void reset()
        {
            timer = new Stopwatch();
            timer.Start();

            nextFreeID = 1;
            idTranslations = new Dictionary<int, int>();
            positions = new Dictionary<int, List<Vector2D>>();
            lastUpdates = new Dictionary<int, long>();

        }

        public void touchDown(object sender, TouchEventArgs tea)
        {
            int id = nextFreeID;
            nextFreeID++;

            idTranslations.Add(tea.TrackID, id);
            positions.Add(id, new List<Vector2D>());
            positions[id].Add(tea.RelativePosition);
            lastUpdates.Add(id, timer.ElapsedMilliseconds);
        }


        public void touchMove(object sender, TouchEventArgs tea)
        {
            int id = idTranslations[tea.TrackID];
            positions[id].Add(tea.RelativePosition);
            lastUpdates[id] = timer.ElapsedMilliseconds;
        }

        public void touchUp(object sender, TouchEventArgs tea)
        {
            int id = idTranslations[tea.TrackID];
            positions[id].Add(tea.RelativePosition);
            lastUpdates[id] = timer.ElapsedMilliseconds;

            idTranslations.Remove(tea.TrackID);
        }

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

            List<int> ids = new List<int>(lastUpdates.Keys);
            for (int i = ids.Count - 1; i >= 0; i--) {
                int id = ids[i];
                if (currentTime - lastUpdates[id] > Constants.TouchEventVisualizerFadeOutTime) {
                    positions.Remove(id);
                    lastUpdates.Remove(id);
                }
            }

            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);
            }
                        
            for (int row = 0; row < numRows; row++) {
                for (int col = 0; col < numColumns; col++) {
                    int x = (int)((col+0.5f)*widthPerColumn)-5;
                    int y = (int)((row+0.5f)*heightPerRow)+5;
                    OutputImage.drawText(x,y,(1+row*numColumns+col).ToString(),Constants.TouchEventVisualizerTextColor);
                }
            }

            foreach (int id in positions.Keys)
                drawTouchGesture(positions[id], 1 - ((currentTime - lastUpdates[id]) / (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);
        }
    }
}