import { BadRequestException } from '@nestjs/common';
import { faToEn } from '../modules/customer-auth/digits';

/**
 * PERS-03: the birth date both customer forms collect (legacy bulkCustomer
 * `birth_date`, singleCustomer `birth_day`). DateInput sends the Gregorian
 * 'YYYY-MM-DD' of the Jalali date picked; stored at UTC midnight, as the
 * import stores legacy's. undefined = not sent (leave as is), '' = cleared.
 *
 * Shared by the admin customer forms and the sales expert's «ویرایش مشتری» in
 * the app, so both read a date the same way.
 */
export function birthDateOrNull(raw: unknown): Date | null | undefined {
  if (raw === undefined) return undefined;
  if (raw === null || String(raw).trim() === '') return null;
  const m = /^(\d{4})-(\d{1,2})-(\d{1,2})/.exec(String(raw).trim());
  const d = m ? new Date(Date.UTC(+m[1], +m[2] - 1, +m[3])) : null;
  if (!d || d.getUTCMonth() !== +m![2] - 1 || d.getUTCFullYear() < 1900 || d > new Date()) {
    throw new BadRequestException('تاریخ تولد معتبر نیست');
  }
  return d;
}

/**
 * A national code as the operator typed it, digits normalised; empty -> null.
 * The column is optional and unique (2026-10-07): an absent code is NULL,
 * never the mobile or '' — two customers without one must not collide, and
 * the column must only ever hold a national code.
 */
export function nationalCodeOrNull(raw: unknown): string | null {
  return faToEn(String(raw ?? '').trim()) || null;
}