class RedditNewOld
{
  // required: an id for this behavior, will be displayed in the logs
  // when the behavior is run.
  static id = "reddit-new-old";

  // required: a function that checks if a behavior should be run
  // for a given page.
  // This function can check the DOM / window.location to determine
  // what page it is on. The first behavior that returns 'true'
  // for a given page is used on that page.
  static isMatch() {
    return window.location.href.match(
      /https:\/\/(www\.)?reddit\.com\/r\/[A-Za-z0-9]+(\/?$|best|hot|new|rising|top\/?(\?t=(hour|day|week|month|year|all))?|\/comments\/.+)$/
    );
  }

  // required: typically should be left as-is.
  // must return an object, with optional fields:
  //   state: passes fixed state to behavior context (ctx)
  //   opts: passes options to behavior context (ctx). this may be
  // useful when injecting behaviors directly into the browser, and
  // provides a basis for passing options to custom behaviors from
  // browsertrix and archiveweb.page in the future.
  static init() {
    return {};
  }

  // optional: if true, will also check isMatch() and possibly run
  // this behavior in each iframe.
  // if false, or not defined, this behavior will be skipped for iframes.
  static runInIframe = false;

  // optional: if defined, provides a way to define a custom way to determine
  // when a page has finished loading beyond the standard 'load' event.
  //
  // if defined, the crawler will await 'awaitPageLoad()' before moving on to
  // post-crawl processing operations, including link extraction, screenshots,
  // and running main behavior
  async awaitPageLoad() {

  }

  // required: the main behavior async iterator, which should yield for
  // each 'step' in the behavior.
  // When the iterator finishes, the behavior is done.
  // (See below for more info)
  async* run(ctx) {
    const { Lib } = ctx;

    // archive the old view of the subreddit as well
    const url = new URL(window.location.href)
    if (url.hostname === "reddit.com" || url.hostname === "www.reddit.com") {
      url.hostname = "old.reddit.com";
    }
    const old_url = url.toString();

    await Lib.addLink(old_url);
    yield Lib.getState(ctx, "old-reddit link added to queue");
  }
}