import { z } from "zod";

/** @see https://github.com/colinhacks/zod/issues/3155#issuecomment-2060045794 */

export const emailRegex =
  /* eslint-disable-next-line no-useless-escape */
  /^(?!\.)(?!.*\.\.)([A-Z0-9_+-\.']*)[A-Z0-9_+'-]@([A-Z0-9][A-Z0-9\-]*\.)+[A-Z]{2,}$/i;

/**
 * Domain regex for watchlist entries
 * Supports international domains with Unicode characters
 * Examples: example.com, münchen.de, example.co.uk
 */
export const domainRegex =
  /^[a-zA-Z0-9\u00a1-\uffff]([a-zA-Z0-9\u00a1-\uffff-]*[a-zA-Z0-9\u00a1-\uffff])?(\.[a-zA-Z0-9\u00a1-\uffff]([a-zA-Z0-9\u00a1-\uffff-]*[a-zA-Z0-9\u00a1-\uffff])?)*$/;

/**
 * RFC 5321 Section 4.5.3.1.3 specifies:
 * - Maximum email address length: 254 characters
 * - Local part (before @): max 64 characters
 * - Domain part (after @): max 253 characters
 */
const MAX_EMAIL_LENGTH = 254;

export const emailSchema = z
  .string()
  .max(MAX_EMAIL_LENGTH, { message: "Email address is too long" })
  .regex(emailRegex);