using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using bbiwarg.Utility;
using Emgu.CV;

namespace bbiwarg.Recognition.FingerRecognition
{
    class FingerSliceTrail
    {
        private List<FingerSlice> slices;
        private LineSegment2D lineSegment;
        private Contour<Point> contour;
        private Contour<Point> innerContour;
        private bool lineSegmentUpToDate;
        private bool contourUpToDate;
        private bool innerContourUpToDate;

        public FingerSlice StartSlice { get { return slices[0]; } }
        public FingerSlice MidSlice { get { return slices[NumSlices / 2]; } }
        public FingerSlice EndSlice { get { return slices[slices.Count - 1]; } }
        public FingerSlice this[int index] { get { return slices[index]; } }
        public int NumSlices { get { return slices.Count; } }
        public LineSegment2D LineSegment { get { if (!lineSegmentUpToDate) updateLineSegment(); return lineSegment; } }
        public Contour<Point> Contour { get { if (!contourUpToDate) updateContour(); return contour; } }
        public Contour<Point> InnerContour { get { if (!innerContourUpToDate) updateInnerContour(); return innerContour; } }

        public FingerSliceTrail(FingerSlice slice)
        {
            slices = new List<FingerSlice>();
            addSlice(slice);
            lineSegmentUpToDate = false;
            contourUpToDate = false;
        }

        public void addSlice(FingerSlice slice)
        {
            slices.Add(slice);
            lineSegmentUpToDate = false;
            contourUpToDate = false;
        }

        public Vector2D getStartDirection()
        {
            int innerStartIndex = Math.Min(NumSlices, Constants.FingerNumSlicesForRelativeDirection);
            return (StartSlice.Mid - slices[innerStartIndex].Mid).normalize();
        }

        public Vector2D getEndDirection()
        {
            int innerEndIndex = Math.Max(0, NumSlices - Constants.FingerNumSlicesForRelativeDirection);
            return (EndSlice.Mid - slices[innerEndIndex].Mid).normalize();
        }

        public void removeFirstSlices(int numSlices)
        {
            slices.RemoveRange(0, numSlices);
            lineSegmentUpToDate = false;
            contourUpToDate = false;
        }

        public void reverse()
        {
            slices.Reverse();
            lineSegmentUpToDate = false;
            contourUpToDate = false;
        }

        private void updateLineSegment()
        {
            lineSegment = new LineSegment2D(EndSlice.Mid, StartSlice.Mid);
            lineSegmentUpToDate = true;
        }

        private void updateContour()
        {
            List<Point> pointsA = new List<Point>();
            List<Point> pointsB = new List<Point>();

            foreach (FingerSlice slice in slices)
            {
                pointsA.Add(slice.StartOuter);
                pointsB.Add(slice.EndOuter);
            }

            pointsA.Reverse();
            pointsA.AddRange(pointsB);

            contour = new Contour<Point>(new MemStorage());
            foreach (Point p in pointsA)
            {
                contour.Push(p);
            }
            contourUpToDate = true;
        }

        private void updateInnerContour()
        {
            List<Point> pointsA = new List<Point>();
            List<Point> pointsB = new List<Point>();

            foreach (FingerSlice slice in slices)
            {
                pointsA.Add(slice.Start);
                pointsB.Add(slice.End);
            }

            pointsA.Reverse();
            pointsA.AddRange(pointsB);

            innerContour = new Contour<Point>(new MemStorage());
            foreach (Point p in pointsA)
            {
                innerContour.Push(p);
            }
            innerContourUpToDate = true;
        }




    }
}