tubearchivist-frontend/public/js/cast-videos.js

function initializeCastApi() {
    cast.framework.CastContext.getInstance().setOptions({
        receiverApplicationId: chrome.cast.media.DEFAULT_MEDIA_RECEIVER_APP_ID, // Use built in reciver app on cast device, see https://developers.google.com/cast/docs/styled_receiver if you want to be able to add a theme, splash screen or watermark. Has a $5 one time fee.
        autoJoinPolicy: chrome.cast.AutoJoinPolicy.ORIGIN_SCOPED
    });

    var player = new cast.framework.RemotePlayer();
    var playerController = new cast.framework.RemotePlayerController(player);

    // Add event listerner to check if a connection to a cast device is initiated
    playerController.addEventListener(
        cast.framework.RemotePlayerEventType.IS_CONNECTED_CHANGED, function() { 
            castConnectionChange(player) 
        }
    );
    playerController.addEventListener(
        cast.framework.RemotePlayerEventType.CURRENT_TIME_CHANGED, function() { 
            castVideoProgress(player) 
        }
    );
    playerController.addEventListener(
        cast.framework.RemotePlayerEventType.IS_PAUSED_CHANGED, function() { 
            castVideoPaused(player) 
        }
    );
}


function castConnectionChange(player) {
    // If cast connection is initialized start cast
    if (player.isConnected) {
        // console.log("Cast Connected.");
        castStart();
    } else if (!player.isConnected) {
        // console.log("Cast Disconnected.");
    }
}

function castVideoProgress(player) {
    var videoId = getVideoPlayerVideoId();
    if (player.mediaInfo.contentId.includes(videoId)) {
        var currentTime = player.currentTime;
        var duration = player.duration;
        if ((currentTime % 10) <= 1.0 && currentTime != 0 && duration != 0) { // Check progress every 10 seconds or else progress is checked a few times a second
            postVideoProgress(videoId, currentTime);
            setProgressBar(videoId, currentTime, duration);
            if (!getVideoPlayerWatchStatus()) { // Check if video is already marked as watched
                if (watchedThreshold(currentTime, duration)) {
                    isWatched(videoId);
                }
            }
        }
    }
}

function castVideoPaused(player) {
    var videoId = getVideoPlayerVideoId();
    var currentTime = player.currentTime;
    var duration = player.duration;
    if (player.mediaInfo != null) {
        if (player.mediaInfo.contentId.includes(videoId)) {
            if (currentTime != 0 && duration != 0) {
                postVideoProgress(videoId, currentTime);
            }
        }
    }
}

function castStart() {
    var castSession = cast.framework.CastContext.getInstance().getCurrentSession();
    // Check if there is already media playing on the cast target to prevent recasting on page reload or switching to another video page
    if (!castSession.getMediaSession()) { 
        var videoId = getVideoPlayerVideoId();
        var videoData = getVideoData(videoId);
        var contentId = getURL() + videoData.data.media_url;
        var contentTitle = videoData.data.title;
        var contentImage = getURL() + videoData.data.vid_thumb_url;

        contentType = 'video/mp4'; // Set content type, only videos right now so it is hard coded
        contentCurrentTime = getVideoPlayerCurrentTime(); // Get video's current position
        contentActiveSubtitle = [];
        // Check if a subtitle is turned on.
        for (var i = 0; i < getVideoPlayer().textTracks.length; i++) {
            if (getVideoPlayer().textTracks[i].mode == "showing") {
                contentActiveSubtitle =[i + 1];
            }
        }
        contentSubtitles = [];
        var videoSubtitles = videoData.data.subtitles; // Array of subtitles
        if (typeof(videoSubtitles) != 'undefined' && videoData.config.downloads.subtitle) {
            for (var i = 0; i < videoSubtitles.length; i++) {
                subtitle = new chrome.cast.media.Track(i, chrome.cast.media.TrackType.TEXT);
                subtitle.trackContentId = videoSubtitles[i].media_url;
                subtitle.trackContentType = 'text/vtt';
                subtitle.subtype = chrome.cast.media.TextTrackType.SUBTITLES;
                subtitle.name = videoSubtitles[i].name;
                subtitle.language = videoSubtitles[i].lang;
                subtitle.customData = null;
                contentSubtitles.push(subtitle);
            }
        }

        mediaInfo = new chrome.cast.media.MediaInfo(contentId, contentType); // Create MediaInfo var that contains url and content type
        // mediaInfo.streamType = chrome.cast.media.StreamType.BUFFERED; // Set type of stream, BUFFERED, LIVE, OTHER
        mediaInfo.metadata = new chrome.cast.media.GenericMediaMetadata(); // Create metadata var and add it to MediaInfo
        mediaInfo.metadata.title = contentTitle.replace("&amp;", "&"); // Set the video title
        mediaInfo.metadata.images = [new chrome.cast.Image(contentImage)]; // Set the video thumbnail
        // mediaInfo.textTrackStyle = new chrome.cast.media.TextTrackStyle();
        mediaInfo.tracks = contentSubtitles;

        var request = new chrome.cast.media.LoadRequest(mediaInfo); // Create request with the previously set MediaInfo. 
        // request.queueData = new chrome.cast.media.QueueData(); // See https://developers.google.com/cast/docs/reference/web_sender/chrome.cast.media.QueueData for playlist support.
        request.currentTime = shiftCurrentTime(contentCurrentTime); // Set video start position based on the browser video position
        request.activeTrackIds = contentActiveSubtitle; // Set active subtitle based on video player
        // request.autoplay = false; // Set content to auto play, true by default
        castSession.loadMedia(request).then(
            function() { 
                castSuccessful();
            }, 
            function() { 
                castFailed(errorCode); 
            }
        ); // Send request to cast device
    }   
}

function shiftCurrentTime(contentCurrentTime) { // Shift media back 3 seconds to prevent missing some of the content
    if (contentCurrentTime > 5) {
        return(contentCurrentTime - 3);
    } else {
        return(0);
    }
}

function castSuccessful() {
    // console.log('Cast Successful.');
    getVideoPlayer().pause(); // Pause browser video on successful cast
}

function castFailed(errorCode) {
    console.log('Error code: ' + errorCode);
}

window['__onGCastApiAvailable'] = function(isAvailable) {
    if (isAvailable) {
        initializeCastApi();
    }
}