using System;
using BigInt;
using System.Text;
using System.Runtime.CompilerServices;

namespace Crypto.EC
{
	public class CurvePoint
	{
		public CurvePoint(EllipticCurve curve,UInteger x,UInteger y){
			Curve = curve;
			X = x;
			Y = y;
		}

		public string toHexString(){
			StringBuilder sb = new StringBuilder();
			sb.Append(X.toHexString());
			sb.Append(".");
			sb.Append(Y.toHexString());
			return sb.ToString();
		}

		public EllipticCurve Curve { get; private set; }
		public UInteger X { get; private set; }
		public UInteger Y { get; private set; }

		public bool isOnCurve(){
			return this.Curve.isOnCurve(this);
		}

		public static CurvePoint operator +(CurvePoint p1, CurvePoint p2)
		{
			return p1.Curve.Add(p1,p2);
		}
		public static CurvePoint operator *(CurvePoint p1, UInteger n)
		{
			if (p1.Y == UInteger.ZERO){
				throw new NotImplementedException("Eternity point not implemented");
			}

			CurvePoint result = null;
			CurvePoint p = p1;

			int i;

			for (i = 0; i < 256; i++)
			{
				if (n[i]){
					result = p;
					break;
				}
				p += p;
			}
			for (; i < 256; i++)
			{
				p += p;
				if (n[i]){
					result += p;
				}
			}

			return result;
		}

		public static bool operator ==(CurvePoint p1, CurvePoint p2)
		{
			if (((object)p1 == null)||((object)p2==null)){
				return false;
			}
			return (p1.X == p2.X) && (p1.Y == p2.Y);
		}
		public static bool operator !=(CurvePoint p1, CurvePoint p2)
		{
			return (p1.X != p2.X) || (p1.Y != p2.Y);
		}

		public override bool Equals(object obj)
		{
			if (this.GetType().IsInstanceOfType(obj)){
				return (this == (CurvePoint)obj);
			} else {
				return false;
			}
		}


	}
}