import { ApiError } from './board.mjs';

const COOKIE = 'ridebus_board_device';
const tokenFrom = req => { const value = req.headers.cookie?.split(';').map(item => item.trim()).find(item => item.startsWith(`${COOKIE}=`))?.slice(COOKIE.length + 1); return /^[A-Za-z0-9_-]{43}$/.test(value || '') ? value : ''; };
export function createDeviceBridge({ enabled = process.env.BOARD_REMOTE_SETTINGS === 'true', baseUrl = process.env.RIDEBUS_API_BASE_URL || 'https://api.ridebus.by/', adminUrl = process.env.BOARD_ADMIN_URL || '', fetchData = fetch } = {}) {
  const cache = new Map();
  async function upstream(path, token, body) {
    let response;
    try { response = await fetchData(new URL(`api/v1/board-devices/${path}`, baseUrl.endsWith('/') ? baseUrl : `${baseUrl}/`), {
      method: body === undefined ? 'GET' : 'POST', headers: { Accept: 'application/json', ...(body !== undefined ? { 'Content-Type': 'application/json' } : {}), ...(token ? { 'X-Board-Token': token } : {}) },
      ...(body !== undefined ? { body: JSON.stringify(body) } : {}), redirect: 'error', signal: AbortSignal.timeout(10000),
    }); } catch { throw new ApiError(502, 'devices_unavailable'); }
    if (!response.ok) {
      const codes = { 401: 'device_unpaired', 410: 'device_revoked', 429: 'device_rate_limit' };
      throw new ApiError(codes[response.status] ? response.status : 502, codes[response.status] || 'devices_unavailable');
    }
    return response.json();
  }
  async function status(req, force = false) {
    const token = tokenFrom(req);
    if (!token) return { state: 'unpaired' };
    const cached = cache.get(token);
    if (!force && cached?.until > Date.now()) return cached.value;
    try {
      const value = await upstream('self', token);
      if (cache.size >= 1000) cache.delete(cache.keys().next().value);
      cache.set(token, { value, until: Date.now() + 15000 }); return value;
    } catch (error) { cache.delete(token); if (error.code === 'device_unpaired') return { state: 'unpaired' }; throw error; }
  }
  return {
    enabled,
    async status(req, config) {
      if (!enabled) return { enabled: false };
      const value = await status(req, true);
      return { ...value, enabled: true, adminUrl, ...(value.state === 'paired' ? { config: { ...config, cityId: value.device.cityId, cityName: value.device.cityName, stopName: value.device.stopName, defaultStopId: value.device.settings.stopId } } : {}) };
    },
    async start(req, res) {
      if (!enabled) throw new ApiError(404, 'not_found');
      const previous = await status(req, true).catch(error => { if (error.code === 'device_revoked') return { state: 'revoked' }; throw error; });
      if (['paired', 'pending'].includes(previous.state)) return { ...previous, enabled: true, adminUrl };
      const value = await upstream('pairings', '', req.body || {});
      if (!/^[A-Za-z0-9_-]{43}$/.test(value.token || '')) throw new ApiError(502, 'devices_unavailable');
      const oldToken = tokenFrom(req); if (oldToken) cache.delete(oldToken);
      res.cookie(COOKIE, value.token, { httpOnly: true, sameSite: 'strict', secure: req.secure || req.get('X-Forwarded-Proto') === 'https' || process.env.BOARD_COOKIE_SECURE === 'true', path: '/api', maxAge: 365 * 86400000 });
      const { token: _token, ...publicValue } = value;
      return { ...publicValue, enabled: true, adminUrl };
    },
    async heartbeat(req) {
      if (!enabled || !tokenFrom(req)) throw new ApiError(401, 'device_unpaired');
      return upstream('self/heartbeat', tokenFrom(req), req.body || {});
    },
    async context(req) {
      if (!enabled) return null;
      const value = await status(req);
      if (value.state !== 'paired') throw new ApiError(401, 'device_unpaired');
      return value.device;
    },
  };
}