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

namespace Geo
{
    [Serializable]
    public class Point3d : IVector
    {
        double[] arr;
        //int n = 3;

        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 double Z { get => arr[2]; set => arr[2] = value; }

        public int N => 3;

        //int N { get => n; }

        public Point3d()
        {
            arr = new double[3];
        }

        public Point3d(double x, double y, double z)
        {
            arr = new double[3];
            arr[0] = x; arr[1] = y; arr[2] = z;
        }
        
        public Point3d(double x, double y)
        {
            arr = new double[3];
            arr[0] = x; arr[1] = y; arr[2] = 0;
        }

        public Point3d(Point3d source)
        {
            arr = new double[3];
            arr = (double[])source.arr.Clone();
        }

        public Point3d(double[] source)
        {
            arr = new double[3];
            if (source.Length >= 3) { arr[0] = source[0]; arr[1] = source[1]; arr[2] = source[2]; }
            else if (source.Length == 2) { arr[0] = source[0]; arr[1] = source[1]; }
            else { arr[0] = source[0]; }
        }

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

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

        public Point2d ToPoint2d()
        {
            return new Point2d { X = X, Y = Y };
        }

        public Point3d FromArray(double[] arr)
        {
            X = arr[0]; Y = arr[1]; Z = arr[2];
            return this;
        }

        public double LengthTo(Point3d node)
        {
            Line3d line = new Line3d(this, node);
            return line.Length;
        }

        public double AngleTo(Point3d startPoint, Point3d endPoint)
        {
            Point3d tempNode = new Point3d();

            Line3d tempLine1 = new Line3d(this, startPoint);
            Line3d tempLine2 = new Line3d(this, endPoint);
            double cosTo = Vector3d.CosAngleBetVectors(tempLine1.Directive, tempLine2.Directive);
            return RadToDeg(Math.Acos(cosTo));
        }

        public bool NormalDirection(Point3d startNode, Point3d endNode)
        {
            Line3d tempLine1 = new Line3d(this, startNode);
            Line3d tempLine2 = new Line3d(this, endNode);
            double norm = (tempLine1.Directive ^ tempLine2.Directive).Vz;
            bool res = false;
            if (norm > 0) res = true;
            return res;
        }

        private double RadToDeg(double radians)
        {
            return radians * 180 / Math.PI;
        }

        public static Point3d operator *(Point3d pt, double prime)
        {
            return new Point3d
            {
                X = pt.X * prime,
                Y = pt.Y * prime,
                Z = pt.Z * prime
            };
        }

        public static Vector3d operator -(Point3d pt1, Point3d pt2)
        {
            Vector3d res = new Vector3d();
            res[0] = pt1.X - pt2.X;
            res[1] = pt1.Y - pt2.Y;
            res[2] = pt1.Z - pt2.Z;
            return res;
        }

        public static bool operator ==(Point3d p1, Point3d p2)
        {
            bool check = false;
            if (p1.X == p2.X && p1.Y == p2.Y && p1.Z == p2.Z)
            {
                check = true;
            }
            return (check);
        }

        public static bool operator !=(Point3d p1, Point3d p2)
        {
            bool check = true;
            if (p1.X == p2.X && p1.Y == p2.Y && p1.Z == p2.Z)
            {
                check = false;
            }
            return (check);
        }

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

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