Update users similarity scores

updateUserSimilarityScores.js

async function updateUserSimilarityScores (username) {
  const users = await db.user.getVals()
  const mainUser = await db.user.get(username)

  mainUser.reviews = await getUserMovieReviews(mainUser)
  const mainUserMovies = _.map(mainUser.reviews, 'movieId')

  return Promise.map(users, async function (user) {
    user.reviews = await getUserMutualMovieReviews(user, mainUserMovies)

    if (user.username === mainUser.username) {
      return
    }

    const clonedUsers = filterUserMutualMovies(mainUser, user)

    return db.similarity.put([user.username, mainUser.username].sort().join('-'), {
      euclideanDistance: algorithms.euclideanDistance(clonedUsers[0], clonedUsers[1]),
      pcc: algorithms.pcc(clonedUsers[0], clonedUsers[1]),
      users: [user.username, mainUser.username].sort(),
    })
  })
}