using HalconDotNet;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Bro.UI.hdisplay.ViewROI
{
    public class ROIPolygon : ROI
    {
        private List<double> rows;

        private List<double> cols;

        private double midR, midC;   // midpoint 

        HRegion region;

        private static ROIPolygon instance;

        protected override int NumHandles { get => rows.Count + 1; }
        
        public static ROIPolygon GetCurrentInstance()
        {
            if (instance == null)
                instance = new ROIPolygon();

            return instance;
        }

        private ROIPolygon()
        {
            midR = 0;
            midC = 0;

            rows = new List<double>();
            cols = new List<double>();
        }

        /// <summary>Creates a new ROI instance at the mouse position</summary>
        /// <param name="midX">
        /// x (=column) coordinate for interactive ROI
        /// </param>
        /// <param name="midY">
        /// y (=row) coordinate for interactive ROI
        /// </param>
        public override void createROI(double x, double y)
        {
            region = new HRegion();

            rows.Add(y);
            cols.Add(x);
        }

        public void CreateROIEnd()
        {
            HOperatorSet.GenRegionPolygon(out HObject hObject, new HTuple(rows.ToArray()), new HTuple(cols.ToArray()));
            HOperatorSet.AreaCenter(hObject, out HTuple area, out HTuple row, out HTuple col);

            midR = row;
            midC = col;

        }

        public void DisposeCurrentInstance()
        {
            instance = null;
        }

        /// <summary>Paints the ROI into the supplied window</summary>
		/// <param name="window">HALCON window</param>
		public override void draw(HalconDotNet.HWindow window)
        {
            if (rows.Count > 1)
            {
                region.GenRegionPolygonFilled(new HTuple(rows.ToArray()), new HTuple(cols.ToArray()));
                window.DispRegion(region);
            }
                
            for (int i = 0; i < rows.Count; i++)
            {
                window.DispRectangle2(rows[i], cols[i], 0, 5, 5);
            }

            if (midR != 0 || midC != 0)
                window.DispRectangle2(midR, midC, 0, 5, 5);
        }

        /// <summary> 
        /// Returns the distance of the ROI handle being
        /// closest to the image point(x,y)
        /// </summary>
        /// <param name="x">x (=column) coordinate</param>
        /// <param name="y">y (=row) coordinate</param>
        /// <returns> 
        /// Distance of the closest ROI handle.
        /// </returns>
        public override double distToClosestHandle(double x, double y)
        {

            double max = 10000;
            double[] val = new double[NumHandles];


            for (int i = 0; i < rows.Count; i++)
            {
                val[i] = HMisc.DistancePp(y, x, rows[i], cols[i]);
            }

            val[NumHandles - 1] = HMisc.DistancePp(y, x, midR, midC); // midpoint 

            for (int i = 0; i < NumHandles; i++)
            {
                if (val[i] < max)
                {
                    max = val[i];
                    activeHandleIdx = i;
                }
            }// end of for 

            return val[activeHandleIdx];
        }

        /// <summary> 
		/// Paints the active handle of the ROI object into the supplied window
		/// </summary>
		/// <param name="window">HALCON window</param>
		public override void displayActive(HalconDotNet.HWindow window)
        {
            if (activeHandleIdx == rows.Count)
                window.DispRectangle2(midR, midC, 0, 5, 5);
            else
                window.DispRectangle2(rows[activeHandleIdx], cols[activeHandleIdx], 0, 5, 5);

        }

        /// <summary>
        /// Gets the HALCON region described by the ROI
        /// </summary>
		public override HRegion getRegion()
        {
            region.GenRegionPolygonFilled(new HTuple(rows.ToArray()), new HTuple(cols.ToArray()));
            return region;
        }

        /// <summary>
        /// Gets the model information described by 
        /// the interactive ROI
        /// </summary> 
        public override HTuple getModelData()
        {
            HTuple val = new HTuple();

            val.Append(new HTuple(rows.ToArray()));
            val.Append(new HTuple(cols.ToArray()));

            return val;
        }


        /// <summary> 
		/// Recalculates the shape of the ROI instance. Translation is 
		/// performed at the active handle of the ROI object 
		/// for the image coordinate (x,y)
		/// </summary>
		/// <param name="newX">x mouse coordinate</param>
		/// <param name="newY">y mouse coordinate</param>
		public override void moveByHandle(double newX, double newY)
        {
            var deltaRow = new List<double>();
            var deltaCol = new List<double>();

            for (int i = 0; i < rows.Count; i++)
            {
                deltaRow.Add(rows[i] - midR);
                deltaCol.Add(cols[i] - midC);
            }

            if (activeHandleIdx == rows.Count)
            {
                midR = newY;
                midC = newX;

                for (int i = 0; i < rows.Count; i++)
                {
                    rows[i] = midR + deltaRow[i];
                    cols[i] = midC + deltaCol[i];
                }
            }
            else
            {
                rows[activeHandleIdx] = newY;
                cols[activeHandleIdx] = newX;
            }


        }//end of method

    }
}