using GeoJSON.Net.Geometry;
using System;

namespace Mapbox.Vector.Tile
{

    public static class CoordinateExtensions
    {
        public static Position ToPosition( this Coordinate c, int x, int y, int z, uint extent )
        {
            var size = extent * Math.Pow(2, z);
            var x0 = extent * x;
            var y0 = extent * y;

            var y2 = 180 - (c.Y + y0) * 360 / size;
            var lon = (c.X + x0) * 360 / size - 180;
            var lat = 360 / Math.PI * Math.Atan(Math.Exp(y2 * Math.PI / 180)) - 90;

            return new Position( lat, lon );
        }
    }

}