import _ from 'lodash';
import type { GroupPermissions, Permissions } from './chmod-calculator.types';

export { computeChmodOctalRepresentation, computeChmodSymbolicRepresentation };

function computeChmodOctalRepresentation({ permissions }: { permissions: Permissions }): string {
  const permissionValue = { read: 4, write: 2, execute: 1 };

  const getGroupPermissionValue = (permission: GroupPermissions) =>
    _.reduce(permission, (acc, isPermSet, key) => acc + (isPermSet ? _.get(permissionValue, key, 0) : 0), 0);

  return [
    getGroupPermissionValue(permissions.owner),
    getGroupPermissionValue(permissions.group),
    getGroupPermissionValue(permissions.public),
  ].join('');
}

function computeChmodSymbolicRepresentation({ permissions }: { permissions: Permissions }): string {
  const permissionValue = { read: 'r', write: 'w', execute: 'x' };

  const getGroupPermissionValue = (permission: GroupPermissions) =>
    _.reduce(permission, (acc, isPermSet, key) => acc + (isPermSet ? _.get(permissionValue, key, '') : '-'), '');

  return [
    getGroupPermissionValue(permissions.owner),
    getGroupPermissionValue(permissions.group),
    getGroupPermissionValue(permissions.public),
  ].join('');
}