import assertString from './util/assertString';
import merge from './util/merge';
var default_fqdn_options = {
  require_tld: true,
  allow_underscores: false,
  allow_trailing_dot: false
};
export default function isFQDN(str, options) {
  assertString(str);
  options = merge(options, default_fqdn_options);
  /* Remove the optional trailing dot before checking validity */

  if (options.allow_trailing_dot && str[str.length - 1] === '.') {
    str = str.substring(0, str.length - 1);
  }

  var parts = str.split('.');

  for (var i = 0; i < parts.length; i++) {
    if (parts[i].length > 63) {
      return false;
    }
  }

  if (options.require_tld) {
    var tld = parts.pop();

    if (!parts.length || !/^([a-z\u00a1-\uffff]{2,}|xn[a-z0-9-]{2,})$/i.test(tld)) {
      return false;
    } // disallow spaces


    if (/[\s\u2002-\u200B\u202F\u205F\u3000\uFEFF\uDB40\uDC20]/.test(tld)) {
      return false;
    }
  }

  for (var part, _i = 0; _i < parts.length; _i++) {
    part = parts[_i];

    if (options.allow_underscores) {
      part = part.replace(/_/g, '');
    }

    if (!/^[a-z\u00a1-\uffff0-9-]+$/i.test(part)) {
      return false;
    } // disallow full-width chars


    if (/[\uff01-\uff5e]/.test(part)) {
      return false;
    }

    if (part[0] === '-' || part[part.length - 1] === '-') {
      return false;
    }
  }

  return true;
}