import {
  LIST_IDS_BY_COMPANY,
  UPDATE_SORT,
} from '../../sql/customergroup.js';
import request from '../request.js';
import resolveCompanyAccess from '../companyuser/resolveCompanyAccess.js';

/**
 * Reorders the customer groups of a company.
 *
 * @param {object} pool - The mssql connection pool.
 * @returns {Function} An async function that reorders customer groups.
 *
 * @example
 * const fn = order(pool);
 * const result = await fn(42, 1, { customergroupIds: [3, 1, 2] });
 * // => { customergroupIds: [3, 1, 2] }
 */
export default function order(pool) {
  const access = resolveCompanyAccess(pool);

  return async (googleAuthId, companyId, { customergroupIds } = {}) => {
    if (!Array.isArray(customergroupIds)) {
      throw new Error('Invalid customer group order');
    }

    await access(googleAuthId, companyId);

    const groups = await pool
      .request()
      .input('companyId', companyId)
      .query(LIST_IDS_BY_COMPANY);

    const existing = new Set(groups.recordset.map((r) => r.id));

    if (customergroupIds.length !== existing.size) {
      throw new Error('Invalid customer group order');
    }

    const seen = new Set();
    for (const customergroupId of customergroupIds) {
      if (
        !Number.isFinite(customergroupId) ||
        !existing.has(customergroupId) ||
        seen.has(customergroupId)
      ) {
        throw new Error('Invalid customer group order');
      }
      seen.add(customergroupId);
    }

    const tx = pool.transaction();
    await tx.begin();

    try {
      for (let sort = 0; sort < customergroupIds.length; sort++) {
        await request(pool, tx)
          .input('id', customergroupIds[sort])
          .input('companyId', companyId)
          .input('sort', sort)
          .query(UPDATE_SORT);
      }

      await tx.commit();

      return { customergroupIds };
    } catch (err) {
      try {
        await tx.rollback();
      } catch {
        // ignore
      }
      throw err;
    }
  };
}