enum PostType: String {

    case image = "image"
    case gif = "gif"
    case video = "video"
    case text = "text"
    case link = "link"
    case audio = "audio"
    case poll = "poll"
    case chat = "chat"
    case quote = "quote"
}

func loadPosts() {
        activityIndicator.startAnimating()
        Api.Feed.observeFeedPosts(withUserId: Api.Users.CURRENT_USER!.uid) {
            post in
            guard let userId = post.userUid else { return }
            self.fetchUser(uid: userId, completed: {
                self.posts.insert(post, at: 0)
                self.activityIndicator.stopAnimating()
                self.collectionView.reloadData()
            })
        }
        Api.Feed.observeFeedRemoved(withUserId: Api.Users.CURRENT_USER!.uid) { (post) in

            self.posts = self.posts.filter { $0.id != post.id } // removed all array elements matching the key
            self.users = self.users.filter { $0.id != post.userUid }
            self.collectionView.reloadData()
        }
    }

    func fetchUser(uid: String, completed: @escaping () -> Void ) {
        Api.Users.observeUsersShort(withId: uid) {
            user in
            self.users.insert(user, at: 0)
            completed()
        }
    }

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return posts.count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CellName.postTextCVC, for: indexPath) as! PostTextCVC
    let user = users[indexPath.row]
    let post = posts[indexPath.row]
    cell.delegatePostTextCVC = self
    cell.user = user
    cell.dashboardVC = self
    cell.post = post
    return cell
}