lib.js

window.BrowserDetector = (function() {
  function detect() {
    var ua = navigator.userAgent;
    var tem;
    var M = ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+\.\d+)/i) || [];

    if (/trident/i.test(M[1])) {
      tem = /\brv[ :]+(\d+\.\d+)/g.exec(ua) || [];
      return {
        name: 'Internet Explorer',
        version: (tem[1] || '')
      };
    }

    if (/(coc_coc_browser|edge(?=\/))\/?\s*(\d+\.\d+)/i.test(ua)) {
      tem = ua.match(/(coc_coc_browser|edge(?=\/))\/?\s*(\d+)\.\d+/i);

      if (tem != null) {
        return {
          name: (tem[1] == 'Edge' ? tem[1] : 'CocCoc'),
          version: tem[2]
        };
      }
    }

    if (M[1] === 'Chrome') {
      tem = ua.match(/\bOPR\/(\d+\.\d+)/);

      if (tem != null) {
        return {
          name: 'Opera',
          version: tem[1]
        };
      }
    }

    M = M[2] ? [M[1], M[2]] : [navigator.appName, navigator.appVersion, '-?'];

    if ((tem = ua.match(/version\/(\d+\.\d+)/i)) != null) {
      M.splice(1, 1, tem[1]);
    }

    if (M[0] == 'MSIE') {
      M[0] = 'Internet Explorer';
    }

    return {
      name: M[0],
      version: M[1]
    };
  }

  var detect = detect();

  return {
    name: detect.name,
    version: detect.version,
    msie: (detect.name == 'Internet Explorer'),
    msedge: (detect.name == 'Edge'),
    coccoc: (detect.name == 'CocCoc'),
    firefox: (detect.name == 'Firefox'),
    safari: (detect.name == 'Safari'),
    chrome: (detect.name == 'Chrome'),
    opera: (detect.name == 'Opera'),
  };
})();

// Leaving just for page to not throw error on body click
function enableSound() {
  return;
}

!function() {
  if (!(BrowserDetector.chrome && BrowserDetector.version >= 66)) {
    return;
  }

  function buildSoundOverlay() {
    const overlay = document.createElement('div');
    overlay.classList.add('sound-overlay');
    overlay.setAttribute('id', 'sound-overlay');
    return overlay;
  }

  function buildSoundText() {
    const textNode = document.createTextNode('Click here to enable sound');
    const textSpan = document.createElement('span');
    textSpan.classList.add('sound-text');
    textSpan.appendChild(textNode);
    return textSpan;
  }

  const soundOverlay = buildSoundOverlay();
  soundOverlay.appendChild(buildSoundText());

  document.addEventListener('DOMContentLoaded', function() {
    var root = document.getElementsByClassName('webgl-content')[0];

    if (!root) {
      root = document.getElementsByClassName('template-wrap')[0];
    }

    root.appendChild(soundOverlay);
  });

  'click removeSoundOverlay'
    .split(' ')
    .forEach(e => document.addEventListener(e, function() {
      soundOverlay.style.display = 'none';
    }, false));
}();