function getCookie(name) {
    var cookieValue = null;
    if (document.cookie && document.cookie !== '') {
        var cookies = document.cookie.split(';');
        for (var i = 0; i < cookies.length; i++) {
            var cookie = cookies[i].trim();
            // Does this cookie string begin with the name we want?
            if (cookie.substring(0, name.length + 1) === (name + '=')) {
                cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
                break;
            }
        }
    }
    return cookieValue;
}

var csrftoken = getCookie('csrftoken');
var button = document.getElementById("BUTTON");
var count = document.getElementById("COUNT");

button.addEventListener("click", event => {
    button.disabled = true;
    fetch('/button', {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
            'X-CSRFToken': csrftoken
        }
    })
        .then((response) => {
            return response.json();
        })
        .then((data) => {
            count.innerText = data.pressed;
        }).finally(() => {
            button.disabled = false;
        });
});

button.focus();