/** Ensure the passed path starts with a leading slash. */
export function ensureLeadingSlash(href: string): string {
  if (href[0] !== "/") href = "/" + href;
  return href;
}

/** Ensure the passed path ends with a trailing slash. */
export function ensureTrailingSlash(href: string): string {
  if (href[href.length - 1] !== "/") href += "/";
  return href;
}

/** Ensure the passed path starts and ends with slashes. */
export function ensureLeadingAndTrailingSlashes(href: string): string {
  href = ensureLeadingSlash(href);
  href = ensureTrailingSlash(href);
  return href;
}

/** Ensure the passed path does not start with a leading slash. */
export function stripLeadingSlash(href: string) {
  if (href[0] === "/") href = href.slice(1);
  return href;
}

/** Ensure the passed path does not end with a trailing slash. */
export function stripTrailingSlash(href: string) {
  if (href[href.length - 1] === "/") href = href.slice(0, -1);
  return href;
}

/** Ensure the passed path does not start and end with slashes. */
export function stripLeadingAndTrailingSlashes(href: string): string {
  href = stripLeadingSlash(href);
  href = stripTrailingSlash(href);
  return href;
}

/** Remove the extension from a path. */
export function stripHtmlExtension(path: string) {
  const pathWithoutTrailingSlash = stripTrailingSlash(path);
  return pathWithoutTrailingSlash.endsWith(".html")
    ? pathWithoutTrailingSlash.slice(0, -5)
    : path;
}

/** Add '.html' extension to a path. */
export function ensureHtmlExtension(path: string) {
  path = stripLeadingAndTrailingSlashes(path);
  if (!path.endsWith(".html")) {
    path = path ? path + ".html" : "/index.html";
  }
  return ensureLeadingSlash(path);
}