import type { GeoPoint } from "../model/mapTypes";

export function pointInPolygon(point: GeoPoint, polygon: GeoPoint[]): boolean {
  if (polygon.length < 3) return false;

  let inside = false;
  for (let i = 0, j = polygon.length - 1; i < polygon.length; j = i++) {
    const pi = polygon[i]!;
    const pj = polygon[j]!;
    const intersects =
      pi.lat > point.lat !== pj.lat > point.lat &&
      point.lon < ((pj.lon - pi.lon) * (point.lat - pi.lat)) / (pj.lat - pi.lat) + pi.lon;

    if (intersects) {
      inside = !inside;
    }
  }

  return inside;
}