//
//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
//

import Foundation
import MediaPlayer

class MediaMessageView: UIView, OWSAudioAttachmentPlayerDelegate {

    let TAG = "[MediaMessageView]"

    // MARK: Properties

    let attachment: SignalAttachment

    var videoPlayer: MPMoviePlayerController?

    var audioPlayer: OWSAudioAttachmentPlayer?
    var audioStatusLabel: UILabel?
    var audioPlayButton: UIButton?
    var playbackState = AudioPlaybackState.stopped {
        didSet {
            AssertIsOnMainThread()

            updateAudioStatusLabel()
            ensureButtonState()
        }
    }

    var audioProgressSeconds: CGFloat = 0
    var audioDurationSeconds: CGFloat = 0

    // MARK: Initializers

    @available(*, unavailable, message:"use attachment: constructor instead.")
    required init?(coder aDecoder: NSCoder) {
        self.attachment = SignalAttachment.empty()
        super.init(coder: aDecoder)
        owsFail("\(self.TAG) invalid constructor")

        createViews()
    }

    required init(attachment: SignalAttachment) {
        assert(!attachment.hasError)
        self.attachment = attachment
        super.init(frame: CGRect.zero)

        createViews()
    }

    // MARK: View Lifecycle

    func viewWillAppear(_ animated: Bool) {
        ViewControllerUtils.setAudioIgnoresHardwareMuteSwitch(true)
    }

    func viewWillDisappear(_ animated: Bool) {
        ViewControllerUtils.setAudioIgnoresHardwareMuteSwitch(false)
    }

    // MARK: - Create Views

    private func createViews() {
        self.backgroundColor = UIColor.white

        if attachment.isAnimatedImage {
            createAnimatedPreview()
        } else if attachment.isImage {
            createImagePreview()
        } else if attachment.isVideo {
            createVideoPreview()
        } else if attachment.isAudio {
            createAudioPreview()
        } else {
            createGenericPreview()
        }
    }

    private func wrapViewsInVerticalStack(subviews: [UIView]) -> UIView {
        assert(subviews.count > 0)

        let stackView = UIView()

        var lastView: UIView?
        for subview in subviews {

            stackView.addSubview(subview)
            subview.autoHCenterInSuperview()

            if lastView == nil {
                subview.autoPinEdge(toSuperviewEdge:.top)
            } else {
                subview.autoPinEdge(.top, to:.bottom, of:lastView!, withOffset:10)
            }

            lastView = subview
        }

        lastView?.autoPinEdge(toSuperviewEdge:.bottom)

        return stackView
    }

    private func createAudioPreview() {
        guard let dataUrl = attachment.dataUrl else {
            createGenericPreview()
            return
        }

        audioPlayer = OWSAudioAttachmentPlayer(mediaUrl: dataUrl, delegate: self)

        var subviews = [UIView]()

        let audioPlayButton = UIButton()
        self.audioPlayButton = audioPlayButton
        setAudioIconToPlay()
        audioPlayButton.imageView?.layer.minificationFilter = kCAFilterTrilinear
        audioPlayButton.imageView?.layer.magnificationFilter = kCAFilterTrilinear
        audioPlayButton.addTarget(self, action:#selector(audioPlayButtonPressed), for:.touchUpInside)
        let buttonSize = createHeroViewSize()
        audioPlayButton.autoSetDimension(.width, toSize:buttonSize)
        audioPlayButton.autoSetDimension(.height, toSize:buttonSize)
        subviews.append(audioPlayButton)

        let fileNameLabel = createFileNameLabel()
        if let fileNameLabel = fileNameLabel {
            subviews.append(fileNameLabel)
        }

        let fileSizeLabel = createFileSizeLabel()
        subviews.append(fileSizeLabel)

        let audioStatusLabel = createAudioStatusLabel()
        self.audioStatusLabel = audioStatusLabel
        updateAudioStatusLabel()
        subviews.append(audioStatusLabel)

        let stackView = wrapViewsInVerticalStack(subviews:subviews)
        self.addSubview(stackView)
        fileNameLabel?.autoPinWidthToSuperview(withMargin: 32)
        stackView.autoPinWidthToSuperview()
        stackView.autoVCenterInSuperview()
    }

    private func createAnimatedPreview() {
        guard attachment.isValidImage else {
            createGenericPreview()
            return
        }
        guard let dataUrl = attachment.dataUrl else {
            createGenericPreview()
            return
        }
        guard let image = YYImage(contentsOfFile:dataUrl.path) else {
            createGenericPreview()
            return
        }
        let animatedImageView = YYAnimatedImageView()
        animatedImageView.image = image
        animatedImageView.contentMode = .scaleAspectFit
        self.addSubview(animatedImageView)
        animatedImageView.autoPinToSuperviewEdges()
    }

    private func createImagePreview() {
        var image = attachment.image
        if image == nil {
            image = UIImage(data:attachment.data)
        }
        guard image != nil else {
            createGenericPreview()
            return
        }

        let imageView = UIImageView(image:image)
        imageView.layer.minificationFilter = kCAFilterTrilinear
        imageView.layer.magnificationFilter = kCAFilterTrilinear
        imageView.contentMode = .scaleAspectFit
        self.addSubview(imageView)
        imageView.autoPinToSuperviewEdges()
    }

    private func createVideoPreview() {
        guard let dataUrl = attachment.dataUrl else {
            createGenericPreview()
            return
        }
        guard let videoPlayer = MPMoviePlayerController(contentURL:dataUrl) else {
            createGenericPreview()
            return
        }
        videoPlayer.prepareToPlay()

        videoPlayer.controlStyle = .default
        videoPlayer.shouldAutoplay = false

        self.addSubview(videoPlayer.view)
        self.videoPlayer = videoPlayer
        videoPlayer.view.autoPinToSuperviewEdges()
    }

    private func createGenericPreview() {
        var subviews = [UIView]()

        let imageView = createHeroImageView(imageName: "file-thin-black-filled-large")
        subviews.append(imageView)

        let fileNameLabel = createFileNameLabel()
        if let fileNameLabel = fileNameLabel {
            subviews.append(fileNameLabel)
        }

        let fileSizeLabel = createFileSizeLabel()
        subviews.append(fileSizeLabel)

        let stackView = wrapViewsInVerticalStack(subviews:subviews)
        self.addSubview(stackView)
        fileNameLabel?.autoPinWidthToSuperview(withMargin: 32)
        stackView.autoPinWidthToSuperview()
        stackView.autoVCenterInSuperview()
    }

    private func createHeroViewSize() -> CGFloat {
        return ScaleFromIPhone5To7Plus(175, 225)
    }

    private func createHeroImageView(imageName: String) -> UIView {
        let imageSize = createHeroViewSize()
        let image = UIImage(named:imageName)
        assert(image != nil)
        let imageView = UIImageView(image:image)
        imageView.layer.minificationFilter = kCAFilterTrilinear
        imageView.layer.magnificationFilter = kCAFilterTrilinear
        imageView.layer.shadowColor = UIColor.black.cgColor
        let shadowScaling = 5.0
        imageView.layer.shadowRadius = CGFloat(2.0 * shadowScaling)
        imageView.layer.shadowOpacity = 0.25
        imageView.layer.shadowOffset = CGSize(width: 0.75 * shadowScaling, height: 0.75 * shadowScaling)
        imageView.autoSetDimension(.width, toSize:imageSize)
        imageView.autoSetDimension(.height, toSize:imageSize)

        return imageView
    }

    private func labelFont() -> UIFont {
        return UIFont.ows_regularFont(withSize:ScaleFromIPhone5To7Plus(18, 24))
    }

    private func formattedFileExtension() -> String? {
        guard let fileExtension = attachment.fileExtension else {
            return nil
        }

        return String(format:NSLocalizedString("ATTACHMENT_APPROVAL_FILE_EXTENSION_FORMAT",
                                               comment: "Format string for file extension label in call interstitial view"),
                      fileExtension.uppercased())
    }

    public func formattedFileName() -> String? {
        guard let sourceFilename = attachment.sourceFilename else {
            return nil
        }
        let filename = sourceFilename.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines)
        guard filename.characters.count > 0 else {
            return nil
        }
        return filename
    }

    private func createFileNameLabel() -> UIView? {
        let filename = formattedFileName() ?? formattedFileExtension()

        guard filename != nil else {
            return nil
        }

        let label = UILabel()
        label.text = filename
        label.textColor = UIColor.ows_materialBlue()
        label.font = labelFont()
        label.textAlignment = .center
        label.lineBreakMode = .byTruncatingMiddle
        return label
    }

    private func createFileSizeLabel() -> UIView {
        let label = UILabel()
        let fileSize = attachment.dataLength
        label.text = String(format:NSLocalizedString("ATTACHMENT_APPROVAL_FILE_SIZE_FORMAT",
                                                     comment: "Format string for file size label in call interstitial view. Embeds: {{file size as 'N mb' or 'N kb'}}."),
                            ViewControllerUtils.formatFileSize(UInt(fileSize)))

        label.textColor = UIColor.ows_materialBlue()
        label.font = labelFont()
        label.textAlignment = .center

        return label
    }

    private func createAudioStatusLabel() -> UILabel {
        let label = UILabel()
        label.textColor = UIColor.ows_materialBlue()
        label.font = labelFont()
        label.textAlignment = .center

        return label
    }

    // MARK: - Event Handlers

    func audioPlayButtonPressed(sender: UIButton) {
        audioPlayer?.togglePlayState()
    }

    // MARK: - OWSAudioAttachmentPlayerDelegate

    public func audioPlaybackState() -> AudioPlaybackState {
        return playbackState
    }

    public func setAudioPlaybackState(_ value: AudioPlaybackState) {
        playbackState = value
    }

    private func ensureButtonState() {
        if playbackState == .playing {
            setAudioIconToPause()
        } else {
            setAudioIconToPlay()
        }
    }

    public func setAudioProgress(_ progress: CGFloat, duration: CGFloat) {
        audioProgressSeconds = progress
        audioDurationSeconds = duration

        updateAudioStatusLabel()
    }

    private func updateAudioStatusLabel() {
        guard let audioStatusLabel = self.audioStatusLabel else {
            owsFail("Missing audio status label")
            return
        }

        let isAudioPlaying = playbackState == .playing
        if isAudioPlaying && audioProgressSeconds > 0 && audioDurationSeconds > 0 {
            audioStatusLabel.text = String(format:"%@ / %@",
                ViewControllerUtils.formatDurationSeconds(Int(round(self.audioProgressSeconds))),
                ViewControllerUtils.formatDurationSeconds(Int(round(self.audioDurationSeconds))))
        } else {
            audioStatusLabel.text = " "
        }
    }

    private func setAudioIconToPlay() {
        let image = UIImage(named:"audio_play_black_large")?.withRenderingMode(.alwaysTemplate)
        assert(image != nil)
        audioPlayButton?.setImage(image, for:.normal)
        audioPlayButton?.imageView?.tintColor = UIColor.ows_materialBlue()
    }

    private func setAudioIconToPause() {
        let image = UIImage(named:"audio_pause_black_large")?.withRenderingMode(.alwaysTemplate)
        assert(image != nil)
        audioPlayButton?.setImage(image, for:.normal)
        audioPlayButton?.imageView?.tintColor = UIColor.ows_materialBlue()
    }
}