// Copyright (c) 2020-2021 Drew Lemmy
// This file is part of KristWeb 2 under AGPL-3.0.
// Full details: https://github.com/tmpim/KristWeb2/blob/master/LICENSE.txt

// Implementation sourced from MDN:
// https://developer.mozilla.org/en-US/docs/Web/API/Web_Storage_API/Using_the_Web_Storage_API#feature-detecting_localstorage
export function localStorageAvailable(
  type: "localStorage" | "sessionStorage" = "localStorage"
): boolean {
  let storage;
  try {
    storage = window[type];
    const x = "__storage_test__";
    storage.setItem(x, x);
    storage.removeItem(x);
    return true;
  } catch(e) {
    return e instanceof DOMException && (
      // everything except Firefox
      e.code === 22 ||
      // Firefox
      e.code === 1014 ||
      // test name field too, because code might not be present
      // everything except Firefox
      e.name === "QuotaExceededError" ||
      // Firefox
      e.name === "NS_ERROR_DOM_QUOTA_REACHED") &&
      // acknowledge QuotaExceededError only if there's something already stored
      (!!storage && storage.length !== 0);
  }
}