likes/unlikes

votesPost: (req, res) => {
    let votesParams = req.params.votes
    let currentThreadId = req.params.id
    let currentUserId = req.user._id
    // TODO: Add Validation if currentUser is already like the post. It's Done!
    if (votesParams === 'likes') {
      User.findById(currentUserId).then(user => {
        Thread.findById(currentThreadId).then(thread => {
          if (user.votedForThreads.indexOf(currentThreadId) > -1) {
            res.render('users/login',
              { globalError: 'You have already voted for this post' })
            return
          }
          user.votedForThreads.push(currentThreadId)
          user.save()
          ++thread.likes
          if (thread.dislikes < 0) {
            ++thread.dislikes
          }
          thread.save()
            .then(() => {
              res.redirect(`/post/${thread._id}/${thread.title}`)
            })
        })
      })
    } else if (votesParams === 'dislikes') {
      User.findById(currentUserId).then(user => {
        Thread.findById(currentThreadId).then(thread => {
          let index = user.votedForThreads.indexOf(thread._id)
          user.votedForThreads.splice(index, 1)
          user.save()
          if (user.votedForThreads.indexOf(currentThreadId) > -1) {
            res.render('users/login',
              { globalError: 'You have already voted for this post' })
            return
          }
          --thread.likes
          if (thread.likes < 0) {
            thread.likes = 0
          }
          --thread.dislikes
          if (thread.dislikes > 0) {
            thread.dislikes = 0
          }
          thread.save().then(() => {
            res.redirect(`/post/${thread._id}/${thread.title}`)
          })
        })
      })
    }
  }