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

import Foundation
import MediaPlayer

class AttachmentApprovalViewController: UIViewController, OWSAudioAttachmentPlayerDelegate {

    let TAG = "[AttachmentApprovalViewController]"

    // MARK: Properties

    let attachment: SignalAttachment

    var successCompletion : (() -> Void)?

    var videoPlayer: MPMoviePlayerController?

    var audioPlayer: OWSAudioAttachmentPlayer?
    var audioPlayButton: UIButton?
    var isAudioPlayingFlag = false
    var isAudioPaused = false

    // MARK: Initializers

    @available(*, unavailable, message:"use attachment: constructor instead.")
    required init?(coder aDecoder: NSCoder) {
        self.attachment = SignalAttachment.attachment(data: nil,
                                                      dataUTI: kUTTypeContent as String,
                                                      filename:nil)
        super.init(coder: aDecoder)
        assertionFailure()
    }

    required init(attachment: SignalAttachment, successCompletion : @escaping () -> Void) {
        assert(!attachment.hasError)
        self.attachment = attachment
        self.successCompletion = successCompletion
        super.init(nibName: nil, bundle: nil)
    }

    // MARK: View Lifecycle

    override func viewDidLoad() {
        super.viewDidLoad()

        view.backgroundColor = UIColor.white

        self.navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem:.stop,
                                                                target:self,
                                                                action:#selector(donePressed))
        self.navigationItem.title = dialogTitle()

        createViews()
    }

    private func dialogTitle() -> String {
        guard let filename = formattedFileName() else {
            return NSLocalizedString("ATTACHMENT_APPROVAL_DIALOG_TITLE",
                                     comment: "Title for the 'attachment approval' dialog.")
        }
        return filename
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        ViewControllerUtils.setAudioIgnoresHardwareMuteSwitch(true)
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)

        ViewControllerUtils.setAudioIgnoresHardwareMuteSwitch(false)
    }

    // MARK: - Create Views

    private func createViews() {
        let previewTopMargin: CGFloat = 30
        let previewHMargin: CGFloat = 20

        let attachmentPreviewView = UIView()
        self.view.addSubview(attachmentPreviewView)
        attachmentPreviewView.autoPinWidthToSuperview(withMargin:previewHMargin)
        attachmentPreviewView.autoPin(toTopLayoutGuideOf: self, withInset:previewTopMargin)

        createButtonRow(attachmentPreviewView:attachmentPreviewView)

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

    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(attachmentPreviewView: UIView) {
        guard let dataUrl = attachment.getTemporaryDataUrl() else {
            createGenericPreview(attachmentPreviewView:attachmentPreviewView)
            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 stackView = wrapViewsInVerticalStack(subviews:subviews)
        attachmentPreviewView.addSubview(stackView)
        fileNameLabel?.autoPinWidthToSuperview(withMargin: 32)
        stackView.autoPinWidthToSuperview()
        stackView.autoVCenterInSuperview()
    }

    private func createAnimatedPreview(attachmentPreviewView: UIView) {
        // Use Flipboard FLAnimatedImage library to display gifs
        guard let animatedImage = FLAnimatedImage(gifData:attachment.data) else {
            createGenericPreview(attachmentPreviewView:attachmentPreviewView)
            return
        }
        let animatedImageView = FLAnimatedImageView()
        animatedImageView.animatedImage = animatedImage
        animatedImageView.contentMode = .scaleAspectFit
        attachmentPreviewView.addSubview(animatedImageView)
        animatedImageView.autoPinWidthToSuperview()
        animatedImageView.autoPinHeightToSuperview()
    }

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

        let imageView = UIImageView(image:image)
        imageView.layer.minificationFilter = kCAFilterTrilinear
        imageView.layer.magnificationFilter = kCAFilterTrilinear
        imageView.contentMode = .scaleAspectFit
        attachmentPreviewView.addSubview(imageView)
        imageView.autoPinWidthToSuperview()
        imageView.autoPinHeightToSuperview()
    }

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

        videoPlayer.controlStyle = .default
        videoPlayer.shouldAutoplay = false

        attachmentPreviewView.addSubview(videoPlayer.view)
        self.videoPlayer = videoPlayer
        videoPlayer.view.autoPinWidthToSuperview()
        videoPlayer.view.autoPinHeightToSuperview()
    }

    private func createGenericPreview(attachmentPreviewView: UIView) {
        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)
        attachmentPreviewView.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())
    }

    private func formattedFileName() -> String? {
        guard let rawFilename = attachment.filename else {
            return nil
        }
        let filename = rawFilename.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.data.count
        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 createButtonRow(attachmentPreviewView: UIView) {
        let buttonTopMargin = ScaleFromIPhone5To7Plus(30, 40)
        let buttonBottomMargin = ScaleFromIPhone5To7Plus(25, 40)
        let buttonHSpacing = ScaleFromIPhone5To7Plus(20, 30)

        let buttonRow = UIView()
        self.view.addSubview(buttonRow)
        buttonRow.autoPinWidthToSuperview()
        buttonRow.autoPinEdge(toSuperviewEdge:.bottom, withInset:buttonBottomMargin)
        buttonRow.autoPinEdge(.top, to:.bottom, of:attachmentPreviewView, withOffset:buttonTopMargin)

        // We use this invisible subview to ensure that the buttons are centered
        // horizontally.
        let buttonSpacer = UIView()
        buttonRow.addSubview(buttonSpacer)
        // Vertical positioning of this view doesn't matter.
        buttonSpacer.autoPinEdge(toSuperviewEdge:.top)
        buttonSpacer.autoSetDimension(.width, toSize:buttonHSpacing)
        buttonSpacer.autoHCenterInSuperview()

        let cancelButton = createButton(title: NSLocalizedString("TXT_CANCEL_TITLE",
                                                                 comment: ""),
                                        color : UIColor.ows_destructiveRed(),
                                        action: #selector(cancelPressed))
        buttonRow.addSubview(cancelButton)
        cancelButton.autoPinEdge(toSuperviewEdge:.top)
        cancelButton.autoPinEdge(toSuperviewEdge:.bottom)
        cancelButton.autoPinEdge(.right, to:.left, of:buttonSpacer)

        let sendButton = createButton(title: NSLocalizedString("ATTACHMENT_APPROVAL_SEND_BUTTON",
                                                               comment: "Label for 'send' button in the 'attachment approval' dialog."),
                                      color : UIColor(rgbHex:0x2ecc71),
                                      action: #selector(sendPressed))
        buttonRow.addSubview(sendButton)
        sendButton.autoPinEdge(toSuperviewEdge:.top)
        sendButton.autoPinEdge(toSuperviewEdge:.bottom)
        sendButton.autoPinEdge(.left, to:.right, of:buttonSpacer)
    }

    private func createButton(title: String, color: UIColor, action: Selector) -> UIButton {
        let buttonFont = UIFont.ows_mediumFont(withSize:ScaleFromIPhone5To7Plus(18, 22))
        let buttonCornerRadius = ScaleFromIPhone5To7Plus(4, 5)
        let buttonWidth = ScaleFromIPhone5To7Plus(110, 140)
        let buttonHeight = ScaleFromIPhone5To7Plus(35, 45)

        let button = UIButton()
        button.setTitle(title, for:.normal)
        button.setTitleColor(UIColor.white, for:.normal)
        button.titleLabel!.font = buttonFont
        button.backgroundColor = color
        button.layer.cornerRadius = buttonCornerRadius
        button.clipsToBounds = true
        button.addTarget(self, action:action, for:.touchUpInside)
        button.autoSetDimension(.width, toSize:buttonWidth)
        button.autoSetDimension(.height, toSize:buttonHeight)
        return button
    }

    // MARK: - Event Handlers

    func donePressed(sender: UIButton) {
        dismiss(animated: true, completion:nil)
    }

    func cancelPressed(sender: UIButton) {
        dismiss(animated: true, completion:nil)
    }

    func sendPressed(sender: UIButton) {
        let successCompletion = self.successCompletion
        dismiss(animated: true, completion: {
            successCompletion?()
        })
    }

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

    // MARK: - OWSAudioAttachmentPlayerDelegate

    public func isAudioPlaying() -> Bool {
        return isAudioPlayingFlag
    }

    public func setIsAudioPlaying(_ isAudioPlaying: Bool) {
        isAudioPlayingFlag = isAudioPlaying
    }

    public func isPaused() -> Bool {
        return isAudioPaused
    }

    public func setIsPaused(_ isPaused: Bool) {
        isAudioPaused = isPaused
    }

    public func setAudioProgressFrom(_ progress: Float) {
        // Ignore
    }

    public func setAudioIconToPlay() {
        let image = UIImage(named:"audio_play_white_large")
        assert(image != nil)
        audioPlayButton?.setImage(image, for:.normal)
    }

    public func setAudioIconToPause() {
        let image = UIImage(named:"audio_pause_white_large")
        assert(image != nil)
        audioPlayButton?.setImage(image, for:.normal)
    }
}