/**
 * Engine client — единая точка вызовов к zeropost-engine
 */
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 { userId, body, method = 'GET' } = options;
  const headers = {
    'Content-Type': 'application/json',
    'x-internal-secret': ENGINE_SECRET,
  };
  if (userId) headers['x-user-id'] = String(userId);

  const url = `${ENGINE_URL}${path}`;
  const res = await fetch(url, {
    method,
    headers,
    body: body ? JSON.stringify(body) : undefined,
    cache: 'no-store',
  });
  if (!res.ok) {
    const err = await res.json().catch(() => ({ error: res.statusText }));
    throw new Error(err.error || `Engine ${res.status}`);
  }
  return res.json();
}

export const engine = {
  // Channels
  listChannels: (userId) => call('/api/channels/', { userId }),
  getChannel: (userId, id) => call(`/api/channels/${id}`, { userId }),
  createChannel: (userId, data) => call('/api/channels/', { userId, method: 'POST', body: data }),
  updateChannel: (userId, id, data) => call(`/api/channels/${id}`, { userId, method: 'PATCH', body: data }),
  deleteChannel: (userId, id) => call(`/api/channels/${id}`, { userId, method: 'DELETE' }),

  // Generation
  generate: (userId, data) => call('/api/generate/', { userId, method: 'POST', body: data }),
  getJob: (userId, id) => call(`/api/generate/${id}`, { userId }),
};