let basePath = '';

/** Sets the library's base path to the specified directory. */
export function setBasePath(path: string) {
  basePath = path;
}

/**
 * Gets the library's base path.
 *
 * The base path is used to load assets such as icons and images, so it needs to be set for components to work properly.
 * By default, this script will look for a script ending in shoelace.js or shoelace-autoloader.js and set the base path
 * to the directory that contains that file. To override this behavior, you can add the data-shoelace attribute to any
 * script on the page (it probably makes the most sense to attach it to the Shoelace script, but it could also be on a
 * bundle). The value can be a local folder or it can point to a CORS-enabled endpoint such as a CDN.
 *
 *   <script src="bundle.js" data-shoelace="/custom/base/path"></script>
 *
 * Alternatively, you can set the base path manually using the exported setBasePath() function.
 *
 * @param subpath - An optional path to append to the base path.
 */
export function getBasePath(subpath = '') {
  if (!basePath) {
    const scripts = [...document.getElementsByTagName('script')] as HTMLScriptElement[];
    const configScript = scripts.find(script => script.hasAttribute('data-shoelace'));

    if (configScript) {
      // Use the data-shoelace attribute
      setBasePath(configScript.getAttribute('data-shoelace')!);
    } else {
      const fallbackScript = scripts.find(s => {
        return /shoelace(\.min)?\.js($|\?)/.test(s.src) || /shoelace-autoloader(\.min)?\.js($|\?)/.test(s.src);
      });
      let path = '';

      if (fallbackScript) {
        path = fallbackScript.getAttribute('src')!;
      }

      setBasePath(path.split('/').slice(0, -1).join('/'));
    }
  }

  // Return the base path without a trailing slash. If one exists, append the subpath separated by a slash.
  return basePath.replace(/\/$/, '') + (subpath ? `/${subpath.replace(/^\//, '')}` : ``);
}