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

namespace Geo
{
    [Serializable]
    public class Point2d
    {
        double[] arr = new double[2];

        public double this[int i] { get => arr[i]; set => arr[i] = value; }
        public double X { get => arr[0]; set => arr[0] = value; }
        public double Y { get => arr[1]; set => arr[1] = value; }

        public Point2d()
        {
            arr = new double[2];
        }

        public Point2d(double x, double y)
        {
            arr = new double[2];
            arr[0] = x; arr[1] = y;
        }

        public Point2d(Point2d source)
        {
            arr = new double[2];
            arr = (double[])source.arr.Clone();
        }

        public Point2d(Point3d source)
        {
            arr = new double[2];
            arr[0]=source.X; arr[1] = source.Y;
        }

        public Point2d(double[] source)
        {
            arr = new double[2];
            if (source.Length >= 2)
            {
                arr[0] = source[0]; arr[1] = source[1];
            }
        }

        public double[] ToArray()
        {
            return new double[] { X, Y };
        }

        public Vector2d ToVector2d()
        {
            return new Vector2d { Vx = X, Vy = Y};
        }

        public Vector3d ToVector3d()
        {
            return new Vector3d { Vx = X, Vy = Y, Vz = 0 };
        }

        public Point3d ToPoint3d()
        {
            return new Point3d { X = X, Y = Y, Z = 0 };
        }

        public Point2d FromArray(double[] arr)
        {
            X = arr[0]; Y = arr[1];
            return this;
        }

        public double LengthTo(Point2d node)
        {
            Line2d line = new Line2d(this, node);
            return line.Length;
        }

        public static Vector2d operator -(Point2d pt1, Point2d pt2)
        {
            Vector2d res = new Vector2d();
            res[0] = pt1.X - pt2.X;
            res[1] = pt1.Y - pt2.Y;
            return res;
        }

        public static bool operator ==(Point2d p1, Point2d p2)
        {
            bool check = false;
            if (p1.X == p2.X && p1.Y == p2.Y)
            {
                check = true;
            }
            return (check);
        }

        public static bool operator !=(Point2d p1, Point2d p2)
        {
            bool check = true;
            if (p1.X == p2.X && p1.Y == p2.Y)
            {
                check = false;
            }
            return (check);
        }

        public override bool Equals(object obj)
        {
            return base.Equals(obj);
        }

        public override int GetHashCode()
        {
            return base.GetHashCode();
        }
    }
}