// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
// This module is browser compatible.

import { extensionsByType } from "./extensions_by_type.ts";

/**
 * For a given media type, return the most relevant extension, or `undefined`
 * if no extension can be found.
 *
 * Extensions are returned without a leading `.`.
 *
 * @example
 * ```ts
 * import { extension } from "@std/media-types/extension";
 *
 * extension("text/plain"); // "txt"
 * extension("application/json"); // "json"
 * extension("text/html; charset=UTF-8"); // "html"
 * extension("application/foo"); // undefined
 * ```
 */
export function extension(type: string): string | undefined {
  const exts = extensionsByType(type);
  if (exts) {
    return exts[0];
  }
  return undefined;
}