benfluleck/HelloBooks

import { nullValidationFnMap, nullValidFieldMessage } from '././validators';

const fieldMap = (bookId, categoryId) => ({
  '/auth/users/signin': ['username',
    'password'],

  '/auth/users/signup': ['email',
    'password',
    'username',
    'firstname',
    'lastname'],

  '/users/changepassword': ['newPassword'],

  '/admin/category': ['categoryName'],

  '/admin/books': ['title',
    'description',
    'author',
    'quantity',
    'categoryId'],

  [`/admin/books/${bookId}`]: ['title',
    'author',
    'description'],

  [`/admin/category/${categoryId}`]: ['categoryName'],

  '/admin/changeuserlevel': ['newLevelId']
});

/**
 * middleware to check for null validations and other bad requests
 * @param {object} req
 *
 * @param {object} res
 *
 * @param {function} next
 *
 * @returns {void|response} res
 */
export default (req, res, next) => {
  const { path } = req;
  const { bookId } = req.params;
  const { categoryId } = req.params;
  const nullField = fieldMap(bookId, categoryId)[path]
    .find((field) => {
      if (req.body[field]) {
        const validationFn = nullValidationFnMap[field];
        return !validationFn.every(fn => fn(req.body[field]));
      }
      return true;
    });
  if (nullField) {
    return res.status(400).send({
      message: nullValidFieldMessage[nullField]

    });
  }
  next();
};