// Client for the learning-lab engine (FastAPI, /api/v1).
// Auth, document upload/Brain and text generation go through the real backend.
(function (root) {
  const BASE = '/api/v1', KEY = 'lle-engine-tokens';
  const Engine = {};

  let tokens = null;
  try { tokens = JSON.parse(localStorage.getItem(KEY) || 'null'); } catch { tokens = null; }
  const save = t => { tokens = t; try { t ? localStorage.setItem(KEY, JSON.stringify(t)) : localStorage.removeItem(KEY); } catch {} };

  class EngineError extends Error { constructor(message, status) { super(message); this.status = status; } }
  const detail = d => typeof d === 'string' ? d : Array.isArray(d) ? d.map(x => x.msg || JSON.stringify(x)).join('; ') : (d && d.message) || 'Permintaan ke engine gagal.';

  // ── Clerk: the only source of organization-scoped tokens (needed by the agents API) ──
  let clerk = null;
  Engine.initClerk = async () => {
    const key = root.LLE_CONFIG?.clerkKey;
    if (!key) return false;
    if (clerk) return true;
    const domain = atob(key.split('_')[2]).replace(/\$$/, '');
    await new Promise((ok, fail) => {
      const s = document.createElement('script');
      s.src = `https://${domain}/npm/@clerk/clerk-js@5/dist/clerk.browser.js`;
      s.async = true; s.crossOrigin = 'anonymous'; s.setAttribute('data-clerk-publishable-key', key);
      s.onload = ok; s.onerror = () => fail(new EngineError('Clerk tidak dapat dimuat.', 0));
      document.head.appendChild(s);
    });
    await root.Clerk.load();
    clerk = root.Clerk;
    return true;
  };
  Engine.clerkEnabled = () => !!clerk;
  Engine.clerkUser = () => clerk?.user && { email: clerk.user.primaryEmailAddress?.emailAddress, name: clerk.user.fullName || clerk.user.firstName };
  Engine.onClerkChange = cb => clerk?.addListener(() => cb());
  Engine.clerkSignIn = () => clerk.openSignIn({});
  // Agents belong to an organization: make sure one is active on the session before asking for a token.
  Engine.ensureOrg = async () => {
    if (!clerk?.session) return null;
    if (!clerk.organization) {
      const memberships = (await clerk.user.getOrganizationMemberships()).data || [];
      if (!memberships.length) return null;
      await clerk.setActive({ organization: memberships[0].organization.id });
    }
    return clerk.organization;
  };

  async function accessToken() {
    if (clerk?.session) return clerk.session.getToken();
    return tokens?.access;
  }

  async function raw(path, opts = {}) {
    const headers = { ...(opts.headers || {}) };
    const access = await accessToken();
    if (access) headers.Authorization = 'Bearer ' + access;
    if (opts.json !== undefined) { headers['Content-Type'] = 'application/json'; opts = { ...opts, body: JSON.stringify(opts.json) }; }
    let res;
    try { res = await fetch(BASE + path, { ...opts, headers }); }
    catch { throw new EngineError('Engine learning-lab tidak dapat dihubungi.', 0); }
    return res;
  }

  let refreshing = null;
  async function refresh() {
    if (!tokens?.refresh) return false;
    refreshing ||= (async () => {
      const res = await fetch(BASE + '/auth/refresh', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ refresh_token: tokens.refresh }) });
      if (!res.ok) { save(null); return false; }
      const body = await res.json();
      save({ access: body.access_token, refresh: body.refresh_token || tokens.refresh });
      return true;
    })().finally(() => { refreshing = null; });
    return refreshing;
  }

  async function call(path, opts = {}) {
    let res = await raw(path, opts);
    if (res.status === 401 && !path.startsWith('/auth/') && await refresh()) res = await raw(path, opts);
    if (res.status === 204) return null;
    const body = await res.json().catch(() => null);
    if (!res.ok) throw new EngineError(detail(body?.detail), res.status);
    return body;
  }

  Engine.hasSession = () => !!(clerk?.session || tokens?.access);
  Engine.login = async (email, password) => {
    const res = await raw('/auth/login', { method: 'POST', json: { email, password } });
    const body = await res.json().catch(() => null);
    if (!res.ok) throw new EngineError(res.status === 401 ? 'Email atau password salah.' : detail(body?.detail), res.status);
    save({ access: body.access_token, refresh: body.refresh_token });
    return body.user;
  };
  Engine.me = () => call('/auth/me');
  Engine.logout = async () => {
    try { if (tokens?.refresh) await call('/auth/logout', { method: 'POST', json: { refresh_token: tokens.refresh } }); } catch {}
    save(null);
    if (clerk?.session) await clerk.signOut();
  };

  let formats = null;
  Engine.supportedExtensions = async () => (formats ||= call('/upload/supported-formats').then(f => new Set(f.extensions)).catch(() => { formats = null; return new Set(); }));

  const asSource = d => ({
    id: 'doc-' + d.id, docId: d.id, remote: true, sample: false,
    title: (d.original_filename || d.filename).replace(/\.[^.]+$/, ''), originalName: d.original_filename || d.filename,
    format: (d.file_type || (d.original_filename || '').split('.').pop() || '').toUpperCase(), tags: [], text: '',
    createdAt: d.created_at, status: d.status, knowledge: d.knowledge_status, progress: d.progress_percentage, stage: d.processing_stage,
  });
  Engine.listDocuments = async () => (await call('/upload/list')).map(asSource);
  Engine.documentStatus = async id => call('/upload/' + id);
  Engine.upload = async file => {
    const form = new FormData(); form.append('file', file, file.name);
    const body = await call('/upload/', { method: 'POST', body: form });
    return { id: body.id ?? body.document_id, raw: body };
  };
  Engine.deleteDocument = id => call('/upload/' + id, { method: 'DELETE' });

  // Building a knowledge base spends workspace credits; a 402 surfaces as an EngineError with the shortfall.
  const BUILDABLE = new Set(['not_built', 'awaiting_confirmation', 'needs_credits', 'failed']);
  Engine.buildKnowledge = async id => {
    const s = await Engine.documentStatus(id);
    if (!BUILDABLE.has(s.knowledge_status)) return s;
    try { await call(`/upload/${id}/knowledge/build`, { method: 'POST' }); }
    catch (e) { throw e.status === 402 ? new EngineError('Kredit tidak cukup untuk membangun knowledge base: ' + e.message, 402) : e; }
    return s;
  };

  // Polls until the document's knowledge base is built (what generation needs).
  Engine.waitReady = async (id, onProgress, { timeoutMs = 10 * 60 * 1000 } = {}) => {
    const t0 = Date.now();
    for (;;) {
      const s = await Engine.documentStatus(id);
      onProgress?.(s);
      if (s.error || s.status === 'failed') throw new EngineError(s.error || 'Dokumen gagal diproses.', 422);
      if (s.knowledge_status === 'ready') return s;
      if (Date.now() - t0 > timeoutMs) throw new EngineError('Pemrosesan dokumen melebihi batas waktu.', 408);
      await new Promise(r => setTimeout(r, 2500));
    }
  };

  // Text content: a compose set over whole documents, then a generated summary.
  Engine.generateText = async (docIds, name) => {
    const set = await call('/compose/sets', { method: 'POST', json: { name, mode: 'knowledge_documents', source_document_ids: docIds } });
    const summary = await call(`/compose/sets/${set.id}/generate/summary`, { method: 'POST', json: { operation_key: `lle-${set.id}-${Date.now()}` } });
    return { setId: set.id, summary };
  };
  Engine.generateQuiz = (setId, n = 5) => call(`/compose/sets/${setId}/generate/quiz`, { method: 'POST', json: { num_questions: n, question_type: 'mixed', operation_key: `lle-q-${setId}-${Date.now()}` } });

  // ── Agents (organization-scoped): research runs and the recurring schedule ──
  const AGENTS = '/organizations/current/agents', AGENT_NAME = 'Learning Lab Express';
  Engine.agentsAvailable = async () => !!(await Engine.ensureOrg());
  let agentCache = null;
  Engine.ensureAgent = async () => {
    if (agentCache) return agentCache;
    let agent = (await call(AGENTS)).find(a => a.name === AGENT_NAME && a.status !== 'archived');
    agent ||= await call(AGENTS, { method: 'POST', json: {
      name: AGENT_NAME, goal: 'Riset topik pembelajaran dan temukan sumber publik baru untuk Brain tim LND.',
      enabled_tools: ['knowledge.retrieve', 'compose.graph.retrieve', 'browse.search', 'library.add_url'],
      research_options: { max_results: 5 }, timezone: 'Asia/Jakarta', run_budget: 50, monthly_budget: 1000,
    } });
    if (agent.status !== 'active') agent = await call(`${AGENTS}/${agent.id}/activate`, { method: 'POST' });
    return (agentCache = agent);
  };
  Engine.attachSources = async (agentId, docIds) => {
    for (const id of docIds) { try { await call(`${AGENTS}/${agentId}/knowledge-sources`, { method: 'PUT', json: { kind: 'document', source_id: id } }); } catch (e) { if (e.status !== 404) throw e; } }
  };
  // Server-side recurring run. weekday: UI uses 0=Sunday, the engine 0=Monday.
  Engine.setSchedule = async ({ enabled, frequency, time, weekday }) => {
    const agent = await Engine.ensureAgent(), [hour, minute] = String(time || '09:00').split(':').map(Number);
    const cadence = !enabled ? 'off' : frequency === 'weekly' ? 'weekly' : 'daily';
    agentCache = await call(`${AGENTS}/${agent.id}`, { method: 'PATCH', json: { run_schedule: { cadence, hour, minute, weekday: (Number(weekday) + 6) % 7 } } });
    return agentCache;
  };
  Engine.research = async ({ topic, prompt, urls = [], docIds = [] }, onStatus) => {
    const agent = await Engine.ensureAgent();
    await Engine.attachSources(agent.id, docIds);
    const focus = [topic && `Topik: ${topic}`, prompt, urls.length && `Referensi: ${urls.join(' ')}`].filter(Boolean).join('\n');
    await call(`${AGENTS}/${agent.id}`, { method: 'PATCH', json: { goal: (topic ? `Riset topik: ${topic}` : agent.goal).slice(0, 4000), instructions: focus || null } });
    const run = await call(`${AGENTS}/${agent.id}/runs`, { method: 'POST', headers: { 'Idempotency-Key': `lle-${agent.id}-${Date.now()}-${Math.random().toString(36).slice(2, 8)}` }, json: {} });
    for (let detail = run; ; ) {
      onStatus?.(detail);
      if (['completed', 'failed', 'cancelled'].includes(detail.status)) { if (detail.status !== 'completed') throw new EngineError('Riset gagal dijalankan (' + (detail.safe_error_code || detail.status) + ').', 422); break; }
      await new Promise(r => setTimeout(r, 3000));
      detail = await call(`${AGENTS}/${agent.id}/runs/${run.id}`);
    }
    const detail = await call(`${AGENTS}/${agent.id}/runs/${run.id}`);
    const drafts = (await call(`${AGENTS}/${agent.id}/source-drafts`)).filter(d => d.run_id === run.id);
    return { run: detail, drafts };
  };

  root.Engine = Engine; root.EngineError = EngineError;
})(window);