type Item = browser.history.HistoryItem;

const filterHttp = (items: Item[]): Item[] => {
  const httpsHosts = items
    .map((x) => new URL(x.url as string))
    .filter((x) => x.protocol === "https:")
    .map((x) => x.host);
  const hostsSet = new Set(httpsHosts);

  return items.filter((item: Item) => {
    const url = new URL(item.url as string);
    return url.protocol === "https:" || !hostsSet.has(url.host);
  });
};

const filterBlankTitle = (items: Item[]): Item[] => {
  return items.filter((item) => item.title && item.title !== "");
};

const filterByTailingSlash = (items: Item[]): Item[] => {
  const urls = items.map((item) => new URL(item.url as string));
  const simplePaths = urls
    .filter((url) => url.hash === "" && url.search === "")
    .map((url) => url.origin + url.pathname);
  const pathsSet = new Set(simplePaths);

  return items.filter((item) => {
    const url = new URL(item.url as string);
    if (
      url.hash !== "" ||
      url.search !== "" ||
      url.pathname.slice(-1) !== "/"
    ) {
      return true;
    }
    return !pathsSet.has(url.origin + url.pathname.slice(0, -1));
  });
};

const filterByPathname = (items: Item[], min: number): Item[] => {
  const hash: { [key: string]: Item } = {};
  for (const item of items) {
    const url = new URL(item.url as string);
    const pathname = url.origin + url.pathname;
    if (!hash[pathname]) {
      hash[pathname] = item;
    } else if (
      (hash[pathname].url as string).length > (item.url as string).length
    ) {
      hash[pathname] = item;
    }
  }
  const filtered = Object.values(hash);
  if (filtered.length < min) {
    return items;
  }
  return filtered;
};

const filterByOrigin = (items: Item[], min: number): Item[] => {
  const hash: { [key: string]: Item } = {};
  for (const item of items) {
    const origin = new URL(item.url as string).origin;
    if (!hash[origin]) {
      hash[origin] = item;
    } else if (
      (hash[origin].url as string).length > (item.url as string).length
    ) {
      hash[origin] = item;
    }
  }
  const filtered = Object.values(hash);
  if (filtered.length < min) {
    return items;
  }
  return filtered;
};

export {
  filterHttp,
  filterBlankTitle,
  filterByTailingSlash,
  filterByPathname,
  filterByOrigin,
};