mainTableView.isPagingEnabled = true
mainTableView.contentInsetAdjustmentBehavior = .never
mainTableView.showsVerticalScrollIndicator = false
mainTableView.separatorStyle = .none
mainTableView.delegate = self
mainTableView.dataSource = self
mainTableView.prefetchDataSource = self

let videoRef = Storage.storage().reference().child("Videos/\(post.video)")
let _ = videoRef.putFile(from: videoURL, metadata: nil) { metadata, error in
    if let error = error {
        failure(error)
        return
    }
    guard let metadata = metadata else { return }
    let size = metadata.size / 1024 / 1024
    print("File Size: \(size)MB")
    videoRef.downloadURL { (url, error) in
        guard let downloadURL = url else { return }
        var tempPost = post
        tempPost.videoURL = downloadURL
        _publishPostToDatabase(post: tempPost)
    }
}

func queryDataFromCache(key: String, fileExtension: String?, completion: @escaping (_ data: Any?) -> Void){
    if let data = dataFromMemoryCache(key: key) {
        completion(data)
    } else if let data = dataFromDiskCache(key: key, fileExtension: fileExtension) {
        storeDataToMemoryCache(data: data, key: key)
        completion(data)
    } else {
        completion(nil)
    }
}

func stretchProfileBackgroundWhenScroll(offsetY: CGFloat)  {
    let scaleRatio: CGFloat = abs(offsetY)/500.0
    let scaledHeight: CGFloat = scaleRatio * profileBackgroundImgView.frame.height
    profileBackgroundImgView.transform = CGAffineTransform.init(scaleX: scaleRatio + 1.0, y: scaleRatio + 1.0).concatenating(CGAffineTransform.init(translationX: 0, y: scaledHeight))
}

struct Post: Codable{
    var id: String
    var video: String
    var videoURL: URL?
    var videoFileExtension: String?
    var videoHeight: Int
    var videoWidth: Int
    var autherID: String
    var autherName: String
    var caption: String
    var music: String
    var likeCount: Int
    var shareCount: Int
    var commentID: String
}

let isLoading = BehaviorSubject<Bool>(value: true)
let posts = PublishSubject<[Post]>()
let error = PublishSubject<Error>()