contentscript.js

(function() {
    const STORAGE_KEY = "video-volume";
    const MAX_VOL_STORAGE_KEY = "max-global-video-volume";
    const STATUS_KEY = "video-volume-status-per-website";

    let store = chrome.storage || window.storage;
    let runtime = chrome.runtime || window.runtime;

    runtime.onMessage.addListener(function(volume) {
        let host = window.location.host;
        data = {};
        data[STORAGE_KEY + '_' + host] = Math.round(volume);
        saveVolumne(data);
    });

    lock = false;
    function setVolume() {
        let host = window.location.host;
        let key = STATUS_KEY + '_' + host;
        let websiteKey = STORAGE_KEY + '_' + host;

        store.local.get([key, MAX_VOL_STORAGE_KEY, websiteKey, STORAGE_KEY], function(data) {

            var videoTags = Array.from(document.getElementsByTagName("video"));
            var audioTags = Array.from(document.getElementsByTagName("audio"));

            var iframes = document.getElementsByTagName('iframe')
            if (iframes.length) {
                for (var x = 0; x < iframes.length; x++) {
                    var iframe = iframes[x];
                    if (iframe.contentDocument) {
                        videoTags = videoTags.concat(Array.from(iframe.contentDocument.getElementsByTagName('video')))
                        audioTags = audioTags.concat(Array.from(iframe.contentDocument.getElementsByTagName('audio')))
                    }
                }
            }

            if (videoTags.length == 0 && audioTags.length == 0) {
                return;
            }

            if (lock) {
                return;
            }

            let maxVol = data[MAX_VOL_STORAGE_KEY] || 0.5;

            for (var x = 0; x < videoTags.length; x++) {
                if (websiteKey in data && key in data && data[key] === true) {
                    videoTags[x].volume = data[websiteKey] / 100;
                } else if (maxVol / 100 < videoTags[x].volume) {
                    videoTags[x].volume = maxVol / 100;
                }
            }
            for (var x = 0; x < audioTags.length; x++) {
                if (websiteKey in data && key in data && data[key] === true) {
                    audioTags[x].volume = data[websiteKey] / 100;
                } else if (maxVol / 100 < audioTags[x].volume) {
                    audioTags[x].volume = maxVol / 100;
                }
            }

            for (var i in videoTags) {
                if (!videoTags[i]) {
                    return;
                }
                if (!(key in data) || !data[key]) {
                    return;
                }
                videoTags[i].onvolumechange = function (argument) {
                    if (argument.target.muted || argument.target.paused) {
                        return;
                    }
                    lock = true;
                    var key = {};
                    key[STORAGE_KEY + '_' + host] = Math.round(argument.target.volume * 100)
                    saveVolumne(key);
                }
            }
            for (var i in audioTags) {
                if (!audioTags[i]) {
                    return;
                }
                if (!(key in data) || !data[key]) {
                    return;
                }
                audioTags[i].onvolumechange = function (argument) {
                    if (argument.target.muted || argument.target.paused) {
                        return;
                    }
                    lock = true;
                    var key = {};
                    key[STORAGE_KEY + '_' + host] = Math.round(argument.target.volume * 100);
                    saveVolumne(key);
                }
            }

        });
    }

    function saveVolumne(data) {
        store.local.set(data, function() {
            lock = false;
        });
    }

    function parseHostFromURL(url) {
        var parser = document.createElement('a');
        parser.href = url;
        return parser.host;
    }

    setVolume();
    window.setInterval(setVolume, 500);
})();