/** @param {number} milliSeconds */
async function sleep(milliSeconds) {
  return new Promise((resolve) => {
    setTimeout(resolve, milliSeconds);
  });
}

const elements = /** @type {HTMLSpanElement[]} */ ([
  ...document.querySelectorAll('span[data-action$="/mark-as-not-watched/"]'),
]);

const tabURL = window.location.href;
const needle = /letterboxd\.com\/[^/]+\/films\/rated\/none\//;

(async () => {
  console.clear();

  if (!needle.test(tabURL)) {
    throw new Error(
      'Only works for pages like "https://letterboxd.com/your-username/films/rated/none/".',
    );
  }

  for (const [index, element] of elements.entries()) {
    console.log(`[${index + 1}/${elements.length}]: ${element.dataset.action}`);

    element.click();

    await sleep(1000);
  }
})().catch((exception) => console.error(exception));