const ENGINE_URL = process.env.ENGINE_URL || 'http://127.0.0.1:3040';
const ENGINE_SECRET = process.env.ENGINE_SECRET || 'zeropost_internal_2026';

async function call(path, options = {}) {
  const res = await fetch(`${ENGINE_URL}${path}`, {
    ...options,
    headers: {
      'Content-Type': 'application/json',
      'x-internal-secret': ENGINE_SECRET,
      ...(options.headers || {}),
    },
    cache: options.cache || 'no-store',
    next: options.next,
  });
  if (!res.ok) {
    const txt = await res.text();
    throw new Error(`Engine ${res.status}: ${txt}`);
  }
  return res.json();
}

export async function listArticles({ limit = 20, offset = 0, tag } = {}) {
  const params = new URLSearchParams({ limit, offset });
  if (tag) params.set('tag', tag);
  return call(`/api/articles?${params}`, { next: { revalidate: 60 } });
}

export async function getArticle(slug) {
  try {
    return await call(`/api/articles/${slug}`, { next: { revalidate: 60 } });
  } catch {
    return null;
  }
}

export async function listTags() {
  return call('/api/articles/tags', { next: { revalidate: 300 } });
}

export async function getLive() {
  try { return await call('/api/stats/live', { cache: 'no-store' }); }
  catch { return null; }
}

export async function listSeries() {
  try { return await call('/api/series', { cache: 'no-store' }); }
  catch { return []; }
}

export async function getSeries(slug) {
  try { return await call(`/api/series/${slug}`, { cache: 'no-store' }); }
  catch { return null; }
}

export async function listNotes({ limit = 20 } = {}) {
  try { return await call(`/api/notes?limit=${limit}`, { cache: 'no-store' }); }
  catch { return []; }
}

export async function getStats() {
  try {
    return await call('/api/stats', { cache: 'no-store' });
  } catch {
    return null;
  }
}

export async function generateArticle(data) {
  return call('/api/articles/generate', {
    method: 'POST',
    body: JSON.stringify(data),
  });
}

// ── Admin API ─────────────────────────────────────────────────────────────────

export async function adminListArticles({ limit = 100, offset = 0 } = {}) {
  return call(`/api/articles/admin?limit=${limit}&offset=${offset}`);
}

export async function adminGetArticle(id) {
  return call(`/api/articles/id/${id}`);
}

export async function adminUpdateArticle(id, data) {
  return call(`/api/articles/${id}`, {
    method: 'PATCH',
    body: JSON.stringify(data),
  });
}

export async function adminDeleteArticle(id) {
  return call(`/api/articles/${id}`, { method: 'DELETE' });
}

export async function adminBackfillCovers(limit = 5) {
  return call('/api/articles/backfill-covers', {
    method: 'POST',
    body: JSON.stringify({ limit }),
  });
}

export async function adminGenerateArticle(topic, tags = []) {
  return call('/api/articles/generate', {
    method: 'POST',
    body: JSON.stringify({ topic, tags, autoPublish: false }),
  });
}