// detectPlatform — which platform a URL is on, by host.
//
// Plain JS (with JSDoc types) rather than TS for ONE reason: umtool's
// report-to-video scripts are `.mjs` run by bare `node` (20 in the runtime
// image — no type stripping), and they spawn yt-dlp too, so they need the same
// answer the editor gets. `lib/platform.ts` re-exports this; every TS caller
// keeps importing it from there. Do not grow a second host table anywhere.

/** @typedef {import("./platform").Platform} Platform */

// Forums known to run XenForo, by host. Any other XenForo forum is recognised
// by its thread URL (THREAD_PATH_RE) instead — a host table is a convenience,
// not the rule.
export const XENFORO_HOSTS = ["kiwifarms.st", "kiwifarms.net"];

// Hosts that serve ONE forum under several domains (a page saved from one is a
// page of the same thread on the other). Compared by `sameXenforoForum`.
export const XENFORO_MIRRORS = [["kiwifarms.st", "kiwifarms.net"]];

/**
 * Whether two hosts are the same forum: equal, or mirrors of one another.
 * @param {string} a
 * @param {string} b
 * @returns {boolean}
 */
export function sameXenforoForum(a, b) {
  const x = a.toLowerCase().replace(/^www\./, "");
  const y = b.toLowerCase().replace(/^www\./, "");
  if (x === y) return true;
  return XENFORO_MIRRORS.some((group) => group.includes(x) && group.includes(y));
}

// A XenForo thread path: /threads/<slug>.<id>/ or /threads/<id>/, optionally
// under a prefix (/community/threads/…) or behind index.php? (non-friendly
// URLs).
export const XENFORO_THREAD_PATH_RE = /(?:^|\/|\?)threads\/(?:[^/?#]*\.)?(\d+)(?:\/|$)/;

/**
 * @param {string | undefined | null} url
 * @returns {Platform | null}
 */
export function detectPlatform(url) {
  if (!url) return null;
  try {
    const host = new URL(url).hostname.toLowerCase();
    if (host.endsWith("youtube.com") || host === "youtu.be") return "youtube";
    if (host.endsWith("rumble.com")) return "rumble";
    if (host.endsWith("odysee.com")) return "odysee";
    if (host.endsWith("twitch.tv")) return "twitch";
    if (host.endsWith("kick.com")) return "kick";
    if (host === "x.com" || host.endsWith(".x.com")) return "twitter";
    if (host.endsWith("twitter.com")) return "twitter";
    if (host === "bsky.app" || host.endsWith(".bsky.app")) return "bluesky";
    // archive.org ITEMS only. Not web.archive.org (the Wayback Machine's page
    // captures are a different kind of record) — see lib/archiveOrgId.ts.
    if (host === "archive.org" || host === "www.archive.org") return "archiveorg";
    // bitchute.com, www. and old. (the pages), api. and the seedNNN. media
    // hosts — every host BitChute serves from is the one platform's.
    if (host === "bitchute.com" || host.endsWith(".bitchute.com")) return "bitchute";
    if (XENFORO_HOSTS.some((h) => host === h || host.endsWith(`.${h}`))) {
      return "xenforo";
    }
    const u = new URL(url);
    if (XENFORO_THREAD_PATH_RE.test(u.pathname + u.search)) return "xenforo";
  } catch {
    /* fall through */
  }
  return null;
}