function addTimeStamp() {
  const tstmp = new Date();
  return tstmp.getTime();
}

function wonder_RefreshTitleArtist() {
  const xhr = new XMLHttpRequest();
  const url = "https://onair.e-radio.gr/whatson/athensparty/wonder/NowOnAir.xml?timestamp=" + addTimeStamp();
  
  xhr.open("GET", url, true);
  xhr.responseType = "document";

  xhr.onload = function() {
    if (xhr.status >= 200 && xhr.status < 300) {
      wonder_ShowTitleArtist(xhr.responseXML);
    }
  };

  xhr.send();
}

function wonder_ShowTitleArtist(xml) {
  const songs = xml.getElementsByTagName("Song");
  for (let i = 0; i < songs.length; i++) {
    document.getElementById("wonderTitle").innerHTML = songs[i].getAttribute("title");
  }
  
  const artists = xml.getElementsByTagName("Artist");
  for (let i = 0; i < artists.length; i++) {
    document.getElementById("wonderArtist").innerHTML = artists[i].getAttribute("name");
  }
}

var oRefreshwonder = window.setInterval(wonder_RefreshTitleArtist, 50000);

// Adding an event listener for script load
document.addEventListener('scriptLoaded', function() {
  wonder_RefreshTitleArtist();
});