/**
 * Is validating inputs for the MultiEmailSelect component.
 * We need to allow domains and sub domains starting with a @ here as well
 * @param {String} string
 */
export default function isEmailValidForWhitelist(string) {
  const emailRE = new RegExp(
    /^(.*)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
  );

  return emailRE.test((typeof string === 'string' && string) || '');
}

/**
 * This regex matches text of the following forms:
 * name <something>
 * name (something)
 * "name" <something> (other valid quote symbols: „"'‚)
 * email@domain
 *
 *
 * The regex is made out of the two following parts:
 *
 * (?:([^,;@]+?)\s<)?
 * An optional name. It checks whether the string is preceded by some text that does not contain a comma, semicolon
 * or @ symbol. The quotes are removed in a second step. If a name is present, the next string must be contained in angle
 * brackets "<" and ">" or normal brackets "(" and ")".
 *
 * (?:([^\s<(,]+@[^\s,;)>]+)>?)
 * Basically checks that the thing contains any characters that can be accepted.
 * This excludes commas and semicolons. This allows invalid emails in the above format to be accepted
 * into the input and later on will be flagged up as an invald entry.
 */
// eslint-disable-next-line no-useless-escape
const TEXT_WITH_NAME_REGEX = /(?:([^,;@]+?)\s[<|\(])?(?:([^\s<(,;)>]+)[>|\)]?)/g;

/**
 * This one is the one the type="email" input uses internally, provided by MDN.
 */
const STRICT_EMAIL_REGEX = /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/;

export { isEmailValidForWhitelist, TEXT_WITH_NAME_REGEX, STRICT_EMAIL_REGEX };