
const Ci = SpecialPowers.Ci;
const Cc = SpecialPowers.Cc;

var didDialog;

var timer; // keep in outer scope so it's not GC'd before firing
function startCallbackTimer() {
  didDialog = false;

  // Delay before the callback twiddles the prompt.
  const dialogDelay = 10;

  // Use a timer to invoke a callback to twiddle the authentication dialog
  timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
  timer.init(observer, dialogDelay, Ci.nsITimer.TYPE_ONE_SHOT);
}

var observer = {
  QueryInterface : function (iid) {
    const interfaces = [Ci.nsIObserver,
                        Ci.nsISupports, Ci.nsISupportsWeakReference];

    if (!interfaces.some( function(v) { return iid.equals(v) } ))
      throw Components.results.NS_ERROR_NO_INTERFACE;
      return this;
  },

  observe : function (subject, topic, data) {

    var doc = getDialogDoc();
    if (doc)
      handleDialog(doc);
    else
      startCallbackTimer(); // try again in a bit
  }
};

function getDialogDoc() {
  // Find the <browser> which contains notifyWindow, by looking
  // through all the open windows and all the <browsers> in each.
  var wm = Cc["@mozilla.org/appshell/window-mediator;1"].
           getService(Ci.nsIWindowMediator);
  //var enumerator = wm.getEnumerator("navigator:browser");
  var enumerator = wm.getXULWindowEnumerator(null);

  while (enumerator.hasMoreElements()) {
    var win = enumerator.getNext();
    var windowDocShell = win.QueryInterface(Ci.nsIXULWindow).docShell;

    var containedDocShells = windowDocShell.getDocShellEnumerator(
                                      Ci.nsIDocShellTreeItem.typeChrome,
                                      Ci.nsIDocShell.ENUMERATE_FORWARDS);
    while (containedDocShells.hasMoreElements()) {
      // Get the corresponding document for this docshell
      var childDocShell = containedDocShells.getNext();
      // We don't want it if it's not done loading.
      if (childDocShell.busyFlags != Ci.nsIDocShell.BUSY_FLAGS_NONE)
        continue;
      var childDoc = childDocShell.QueryInterface(Ci.nsIDocShell).
                     contentViewer.DOMDocument;

      //ok(true, "Got window: " + childDoc.location.href);
      if (childDoc.location.href == "chrome://global/content/commonDialog.xul")
        return childDoc;
    }
  }

return null;
}
