hummingbird-me/kitsu-web

import { get } from '@ember/object';
import { isPresent } from '@ember/utils';
import { isArray } from '@ember/array';
import { capitalize } from '@ember/string';

// http://tools.ietf.org/html/rfc6749#section-5.2
const lookupTable = {
  invalid_grant: 'The provided credentials are invalid.'
};

export default function errorMessages(obj) {
  const defaultMessage = 'There was an issue with your request, please try again.';
  let reason = defaultMessage;
  if (obj === undefined) {
    return reason;
  }

  let errors = get(obj, 'payload') || get(obj, 'errors') || get(obj, 'error');
  errors = errors === undefined ? get(obj, 'jqXHR.responseJSON.errors') : errors;
  if (isPresent(errors)) {
    reason = isArray(errors) ? capitalize(get(errors[0], 'detail') || get(errors[0], 'title'))
      : get(lookupTable, errors);
  }
  if (!reason || reason === 'Internal Server Error' || reason.charAt(0) === '<') {
    reason = defaultMessage;
  }
  return reason;
}