import path from "path";
import process from "node:process";

function isStringOrURL(icon: any): icon is string | URL {
  return typeof icon === "string" || icon instanceof URL;
}

function resolveUrl(url: null | undefined, metadataBase: URL | null): null;
function resolveUrl(url: string | URL, metadataBase: URL | null): URL;
function resolveUrl(
  url: string | URL | null | undefined,
  metadataBase: URL | null,
): URL | null;
function resolveUrl(
  url: string | URL | null | undefined,
  metadataBase: URL | null,
): URL | null {
  if (url instanceof URL) return url;
  if (!url) return null;

  try {
    // If we can construct a URL instance from url, ignore metadataBase
    const parsedUrl = new URL(url);
    return parsedUrl;
  } catch (_) {}

  if (!metadataBase) {
    metadataBase = new URL(`http://localhost:${process.env.PORT || 3000}`);
  }

  // Handle relative or absolute paths
  const basePath = metadataBase.pathname || "";
  const joinedPath = path.join(basePath, url);

  return new URL(joinedPath, metadataBase);
}

export { isStringOrURL, resolveUrl };