/*
 * L.Circle is a circle overlay (with a certain radius in meters).
 * It's an approximation and starts to diverge from a real circle closer to poles (due to projection distortion)
 */

L.Circle = L.CircleMarker.extend({

	initialize: function (latlng, radius, options) {
		L.setOptions(this, options);
		this._latlng = L.latLng(latlng);
		this._mRadius = radius;
	},

	setRadius: function (radius) {
		this._mRadius = radius;
		return this.redraw();
	},

	getRadius: function () {
		return this._mRadius;
	},

	getBounds: function () {
		var half = [this._radius, this._radiusY];

		return new L.LatLngBounds(
			this._map.layerPointToLatLng(this._point.subtract(half)),
			this._map.layerPointToLatLng(this._point.add(half)));
	},

	setStyle: L.Path.prototype.setStyle,

	_project: function () {

		var lng = this._latlng.lng,
		    lat = this._latlng.lat,
		    map = this._map,
		    crs = map.options.crs;

		if (crs.distance === L.CRS.Earth.distance) {
			var d = Math.PI / 180,
			    latR = (this._mRadius / L.CRS.Earth.R) / d,
			    top = map.project([lat + latR, lng]),
			    bottom = map.project([lat - latR, lng]),
			    p = top.add(bottom).divideBy(2),
			    lat2 = map.unproject(p).lat,
			    lngR = Math.acos((Math.cos(latR * d) - Math.sin(lat * d) * Math.sin(lat2 * d)) /
			            (Math.cos(lat * d) * Math.cos(lat2 * d))) / d;

			this._point = p.subtract(map.getPixelOrigin());
			this._radius = isNaN(lngR) ? 0 : Math.max(Math.round(p.x - map.project([lat2, lng - lngR]).x), 1);
			this._radiusY = Math.max(Math.round(p.y - top.y), 1);

		} else {
			var latlng2 = crs.unproject(crs.project(this._latlng).subtract([this._mRadius, 0]));

			this._point = map.latLngToLayerPoint(this._latlng);
			this._radius = this._point.x - map.latLngToLayerPoint(latlng2).x;
		}

		this._updateBounds();
	}
});

L.circle = function (latlng, radius, options) {
	return new L.Circle(latlng, radius, options);
};
