const images = document.getElementsByClassName('current_webcam_image');
const reload_interval = setInterval(reloadImages, 60000);

window.onload = function() {
    reloadImages();
  };

function checkImageSource(image_url) {
    var http_request = new XMLHttpRequest();
    http_request.open('HEAD', image_url, false);
    http_request.send();

    return http_request.status;
}

function reloadImages() {
    console.log('reload in progress');

    Array.prototype.forEach.call(images, function(image) {

        if (checkImageSource(image.src) == 200) {
            if (!image.src.includes('?')) {
                image.src = `${image.src}?${Date.now()}`;
            } else {
                image.src = image.src.slice(0, image.src.indexOf('?') + 1) + Date.now();
            }
        } else {
            console.log('unable to find image on server');
            image.alt = "Webcam nicht erreichbar."

            
        }
    });
    console.log('reload finished');
}