const config = require('../config');
const { proxyRequest } = require('./websocket');
const { parseStoreNumber } = require('../utils/validate');
const logger = require('../utils/logger');

function getSiwAuthHeaders() {
  const { username, password } = config.siw;
  if (!username || !password) {
    throw new Error('SIW credentials are not configured (SIW_USERNAME / SIW_PASSWORD)');
  }
  const authString = Buffer.from(`${username}:${password}`).toString('base64');
  return { Authorization: `Basic ${authString}` };
}

function buildSiwRequest(path) {
  if (!config.siw.baseUrl) {
    throw new Error('SIW_BASE_URL is not configured');
  }
  return {
    method: 'GET',
    url: `${config.siw.baseUrl}${path}`,
    headers: getSiwAuthHeaders(),
  };
}

/**
 * Perform a SIW request and gracefully degrade when the remote agent isn't
 * connected. Returns `fallback` (default: null) so downstream code can keep
 * rendering Meraki/MDM sections without crashing.
 *
 * Any other error is propagated so the integration layer can decide whether
 * to swallow or surface it.
 */
async function siwGet(path, { fallback = null, storeNumber } = {}) {
  try {
    const result = await proxyRequest(buildSiwRequest(path));
    return result?.data ?? fallback;
  } catch (err) {
    if (err.code === 'AGENT_NOT_CONNECTED') {
      logger.warn('SIW request skipped — remote agent not connected', { path, storeNumber });
      return fallback;
    }
    throw err;
  }
}

async function getStoreLocation(storeNumber) {
  const normalized = parseStoreNumber(storeNumber);
  if (!normalized) throw new Error('Invalid store number');

  const data = await siwGet(`/StoreLocation/${normalized}`, { storeNumber: normalized });
  if (!data) {
    logger.warn('SIW returned no location record', { storeNumber: normalized });
  }
  return data;
}

/**
 * /StoreGeneral/{n} returns brand info, environment, POS type, status,
 * open/close dates, etc. Distinct from /StoreLocation which is the address.
 */
async function getStoreGeneral(storeNumber) {
  const normalized = parseStoreNumber(storeNumber);
  if (!normalized) throw new Error('Invalid store number');

  const data = await siwGet(`/StoreGeneral/${normalized}`, { storeNumber: normalized });
  if (!data) {
    logger.warn('SIW returned no general record', { storeNumber: normalized });
  }
  return data;
}

async function getStoreRegisters(storeNumber) {
  const normalized = parseStoreNumber(storeNumber);
  if (!normalized) throw new Error('Invalid store number');

  return siwGet(`/StoreRegister/${normalized}`, { fallback: [], storeNumber: normalized });
}

async function getStorePrinters(storeNumber) {
  const normalized = parseStoreNumber(storeNumber);
  if (!normalized) throw new Error('Invalid store number');

  return siwGet(`/StorePrinter/${normalized}`, { fallback: [], storeNumber: normalized });
}

async function getStorePaymentTerminals(storeNumber) {
  const normalized = parseStoreNumber(storeNumber);
  if (!normalized) throw new Error('Invalid store number');

  return siwGet(`/StorePayment/${normalized}`, { fallback: [], storeNumber: normalized });
}

module.exports = {
  getStoreLocation,
  getStoreGeneral,
  getStoreRegisters,
  getStorePrinters,
  getStorePaymentTerminals,
};