(function () {
  var WAIT_MS = 10000;   // durata avviso e blocco click ripetuti
  var busy = false;

  function isDownload(url) {
    url = String(url || "");
    return /\/nodes\/[^\/]+\/content/.test(url) && /[?&](attachment|a)=true/.test(url);
  }

  function banner(msg) {
    var el = document.getElementById("dl-banner");
    if (!el) {
      el = document.createElement("div");
      el.id = "dl-banner";
      el.style.cssText = "position:fixed;top:12px;left:50%;transform:translateX(-50%);" +
        "background:#333;color:#fff;padding:10px 20px;border-radius:4px;" +
        "font:14px sans-serif;z-index:100000;box-shadow:0 2px 8px rgba(0,0,0,.4)";
      document.body.appendChild(el);
    }
    el.textContent = msg;
    el.style.display = "block";
  }

  function lock() {
    busy = true;
    document.body.style.cursor = "progress";
    banner("Downloading ... attendere prego");
    setTimeout(function () {
      busy = false;
      document.body.style.cursor = "";
      var el = document.getElementById("dl-banner");
      if (el) { el.style.display = "none"; }
    }, WAIT_MS);
  }

  // 1) anchor.click() chiamato da codice
  var origClick = HTMLAnchorElement.prototype.click;
  HTMLAnchorElement.prototype.click = function () {
    if (isDownload(this.href)) {
      if (busy) { return; }
      lock();
    }
    return origClick.apply(this, arguments);
  };

  // 2) anchor.dispatchEvent(new MouseEvent('click')) chiamato da codice
  var origDispatch = EventTarget.prototype.dispatchEvent;
  EventTarget.prototype.dispatchEvent = function (ev) {
    if (ev && ev.type === "click" && this instanceof HTMLAnchorElement && isDownload(this.href)) {
      if (busy) { return false; }
      lock();
    }
    return origDispatch.apply(this, arguments);
  };

  // 3) click reale dell'utente su un link (solo eventi "trusted", per non contare due volte)
  document.addEventListener("click", function (e) {
    if (!e.isTrusted) { return; }
    var a = e.target.closest && e.target.closest("a");
    if (a && isDownload(a.href)) {
      if (busy) { e.preventDefault(); e.stopPropagation(); return; }
      lock();
    }
  }, true);
})();