import { CONFIG } from "./config.js";

// Lazily load @huggingface/hub (resolved via the importmap in index.html).
// Dynamic import means a CDN hiccup degrades liking only — never the whole app.
let _hub = null;
async function hub() {
  if (!_hub) _hub = await import("@huggingface/hub");
  return _hub;
}

function load(key) {
  try { return JSON.parse(localStorage.getItem(key) || "null"); } catch { return null; }
}
function save(key, v) {
  try { localStorage.setItem(key, JSON.stringify(v)); } catch { /* ignore */ }
}

/** Returns the active OAuthResult or null (handles the redirect-back leg on load). */
export async function initOAuth() {
  let oauth = null;
  try {
    const { oauthHandleRedirectIfPresent } = await hub();
    oauth = await oauthHandleRedirectIfPresent();
  } catch {
    oauth = null;
  }
  oauth = oauth || load(CONFIG.oauthKey);
  if (oauth) {
    const exp = new Date(oauth.accessTokenExpiresAt).getTime();
    if (Number.isFinite(exp) && exp < Date.now()) oauth = null; // expired
  }
  if (oauth) save(CONFIG.oauthKey, oauth);
  return oauth;
}

export async function signIn() {
  try {
    const { oauthLoginUrl } = await hub();
    const opts = CONFIG.oauthScopes ? { scopes: CONFIG.oauthScopes } : {};
    window.location.href = await oauthLoginUrl(opts);
  } catch {
    /* OAuth lib unavailable — stay signed out; likes go local */
  }
}

export function signOut() {
  try { localStorage.removeItem(CONFIG.oauthKey); } catch { /* ignore */ }
}

/**
 * Attempts a real HF like/unlike. Returns "hf" on success, "local" on any failure/offline.
 * Caller persists the local fallback + UI.
 */
export async function likeOnHf(id, on, token) {
  if (!token) return "local";
  try {
    const res = await fetch(`${CONFIG.apiBase}/api/spaces/${id}/like`, {
      method: on ? "POST" : "DELETE",
      headers: { Authorization: `Bearer ${token}` },
    });
    return res.ok ? "hf" : "local";
  } catch {
    return "local";
  }
}