audio.js

function Audio(game) {

    var files = [],
        endEvents = [],
        progressEvents = [],
        playing = [];

    function load(name, path, cb) {

        var f = files[name] = document.createElement("audio");

        progressEvents[name] = function (event) { progress(event, name, cb); };

        f.addEventListener("canplaythrough", progressEvents[name], true);
        f.setAttribute("preload", "true");
        f.setAttribute("autobuffer", "true");
        f.setAttribute("src", path);
        f.pause();
    };

    function progress(event, name, callback) {
        if (event.loaded === event.total && typeof callback === "function") {
            callback();
            files[name].removeEventListener("canplaythrough",
                progressEvents[name], true);
        }
    };

    function disableSound() {
        for (let i = 0; i < playing.length; i++) {
            files[playing[i]].pause();
            files[playing[i]].currentTime = 0;
        }
        playing = [];
    };

    function ended(name) {

        var tmp = [], found = false;

        files[name].removeEventListener("ended", endEvents[name], true);

        for (let i = 0; i < playing.length; i++) {
            if (!found && playing[i]) {
                found = true;
            } else {
                tmp.push(playing[i]);
            }
        }
        playing = tmp;
    };

    function play(name) {
        if (!game.soundDisabled()) {
            endEvents[name] = function () { ended(name); };
            playing.push(name);
            files[name].addEventListener("ended", endEvents[name], true);
            files[name].play();
        }
    };

    function pause() {
        for (let i = 0; i < playing.length; i++) {
            files[playing[i]].pause();
        }
    };

    function resume() {
        for (let i = 0; i < playing.length; i++) {
            files[playing[i]].play();
        }
    };

    return {
        disableSound: disableSound,
        load: load,
        play: play,
        pause: pause,
        resume: resume
    };
};

export { Audio };