helper.js

/* Generates a random string, used for creating short URLs and userIDs */
function generateRandomString() {
  return Math.random().toString(36).replace(/[^a-z]+/g, '').substr(0, 5);
};

// returns true if the email is already in use
const emailTaken = function(email, userDatabase) {
  for (const user in userDatabase) {
    if (userDatabase[user].email === email) {
      return true;
    }
  }
  return false;
};

// returns the id for the user
const userIdFromEmail = function(email, userDatabase) {
  for (const user in userDatabase) {
    if (userDatabase[user].email === email) {
      return userDatabase[user].id;
    }
  }
};

// returns an object of short urls for the user
const urlsForUser = function(id, urlDatabase) {
  const userUrls = {};
  for (const shortURL in urlDatabase) {
    if (urlDatabase[shortURL].userID === id) {
      userUrls[shortURL] = urlDatabase[shortURL];
    }
  }
  return userUrls;
};

// returns true if the current cookie is found in the users object
const userLoggedIn = function(cookie, userDatabase) {
  for (const user in userDatabase) {
    if (cookie === user) {
      return true;
    }
  } return false;
};

module.exports = {
  generateRandomString,
  emailTaken,
  userIdFromEmail,
  urlsForUser,
  userLoggedIn
};