import {
  CLEAR_COMPANYHISTORY_USER as MSSQL_CLEAR_COMPANYHISTORY,
  CLEAR_ENTITYHISTORY_USER as MSSQL_CLEAR_ENTITYHISTORY,
  CLEAR_SELECTED_COMPANY as MSSQL_CLEAR_SELECTED,
  COUNT_ADMINS as MSSQL_COUNT_ADMINS,
  DELETE as MSSQL_DELETE,
  GET_IN_COMPANY as MSSQL_GET,
} from '../../providers/mssql/queries/companyuser.js';
import {
  CLEAR_COMPANYHISTORY_USER as SQLITE_CLEAR_COMPANYHISTORY,
  CLEAR_ENTITYHISTORY_USER as SQLITE_CLEAR_ENTITYHISTORY,
  CLEAR_SELECTED_COMPANY as SQLITE_CLEAR_SELECTED,
  COUNT_ADMINS as SQLITE_COUNT_ADMINS,
  DELETE as SQLITE_DELETE,
  GET_IN_COMPANY as SQLITE_GET,
} from '../../providers/sqlite3/queries/companyuser.js';
import requireAdmin from './requireAdmin.js';
import withTransaction from './withTransaction.js';

export default function remove(provider) {
  const isSqlite = provider?.dialect === 'sqlite3';
  const pick = (mssql, sqlite) => (isSqlite ? sqlite : mssql);
  const getSql = pick(MSSQL_GET, SQLITE_GET);
  const countSql = pick(MSSQL_COUNT_ADMINS, SQLITE_COUNT_ADMINS);
  const deleteSql = pick(MSSQL_DELETE, SQLITE_DELETE);
  const clearEntityHistorySql = pick(MSSQL_CLEAR_ENTITYHISTORY, SQLITE_CLEAR_ENTITYHISTORY);
  const clearCompanyHistorySql = pick(MSSQL_CLEAR_COMPANYHISTORY, SQLITE_CLEAR_COMPANYHISTORY);
  const clearSelectedSql = pick(MSSQL_CLEAR_SELECTED, SQLITE_CLEAR_SELECTED);
  const admin = requireAdmin(provider);

  /**
   * Removes a member from the admin's selected company. History entries keep
   * existing but lose their author link; if the removed user had this company
   * selected, their selection is cleared.
   *
   * @param {number} googleAuthId - The id of the acting Google auth user (must be admin of the selected company).
   * @param {number} id - The company user id to remove.
   * @param {object} [tx] - Optional transaction to run within.
   * @returns {Promise<{id: number, googleAuthId: number}>} The removed company user.
   * @throws {Error} 'Not authorized', 'Company user not found', 'Cannot remove the last admin'
   *
   * @example
   * await store.companyuser.remove(42, 7);
   */
  return async (googleAuthId, id, tx) =>
    withTransaction(provider, tx, async (runner) => {
      const { companyId } = await admin(googleAuthId, runner);

      const member = (await runner.query(getSql, { id, companyId })).rows[0];
      if (!member) throw new Error('Company user not found');

      if (member.role === 'admin') {
        const { count } = (await runner.query(countSql, { companyId })).rows[0];
        if (Number(count) <= 1) throw new Error('Cannot remove the last admin');
      }

      await runner.query(clearEntityHistorySql, { id });
      await runner.query(clearCompanyHistorySql, { id });
      await runner.query(clearSelectedSql, { googleAuthId: member.googleAuthId, companyId });
      await runner.query(deleteSql, { id });
      return { id: member.id, googleAuthId: member.googleAuthId };
    });
}