// It doesn't matter if the scripts exist or not
// Browser won't try to load them either way
var scripts = [
    '//testdomain.test/script1.js',
    '//testdomain.test/script2.js',
    '//testdomain.test/script3.js'
];

function createIFrame(win, onCreated) {
    var iframe = win.document.createElement('iframe');
    iframe.onload = function () {
        onCreated(iframe);
    };
    win.document.body.appendChild(iframe);
}

function loadScript(win, url) {
    var script = win.document.createElement('script');
    script.src = url;
    script.onload = function() {
        console.log("Script " + url + " is loaded.");
    };
    win.document.getElementsByTagName('head')[0].appendChild(script);
}

createIFrame(window, function(iframe1) {
    loadScript(iframe1.contentWindow, scripts[0]);
    createIFrame(iframe1.contentWindow, function (iframe2) {
        loadScript(iframe2.contentWindow, scripts[1]);
        createIFrame(iframe2.contentWindow, function (iframe3) {
            loadScript(iframe3.contentWindow, scripts[2]);
        });
    });
});

var scripts = [
    'https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.1/jquery.js',
    'https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.2/jquery.js',
    'https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js'
];

function createIFrame(win, onCreated) {
    var iframe = win.document.createElement('iframe');
    iframe.onload = function () {
        onCreated(iframe);
    };
    win.document.body.appendChild(iframe);
}

function loadScript(win, url) {
    var script = win.document.createElement('script');
    script.src = url;
    script.onload = function() {
        console.log("Script " + url + " is loaded.");
    };
    win.document.getElementsByTagName('head')[0].appendChild(script);
}
window.onload = function(){
createIFrame(window, function(iframe1) {
    loadScript(iframe1.contentWindow, scripts[0]);
    createIFrame(iframe1.contentWindow, function (iframe2) {
        loadScript(iframe2.contentWindow, scripts[1]);
        createIFrame(iframe2.contentWindow, function (iframe3) {
            loadScript(iframe3.contentWindow, scripts[2]);
        });
    });
});
};

/* This is valid to omit the http:/https: protocol.
   In that case, browser should automatically append
   protocol used by the parent page */
var scripts = [
    '//testdomain.test/script1.js',
    '//testdomain.test/script2.js',
    '//testdomain.test/script3.js'
];

function appendSchema(win, url) {
    if (url.startsWith('//')) {
        var protocol = 'https:';
        try {
            var wPrev = undefined;
            var wCur = win;
            while (wPrev != wCur) {
                console.log(wCur.location.protocol);
                if (wCur.location.protocol.startsWith("http")) {
                    protocol = wCur.location.protocol;
                    break;
                }
                wPrev = wCur;
                wCur = wCur.parent;
            }
        } catch (e) {
            /* We cannot get protocol of a cross-site iframe.
             * So in case we are inside cross-site iframe, and
             * there are no http/https iframes before it,
             * we will just use https: */
        }
        return protocol + url;
    }
    return url;
}

new URL(scriptURL, window.location.href).toString();

function url(win: Window, path: string): string {
  // We search up the window hierarchy for the first window which uses
  // a protocol that starts with "http".
  while (true) {
    if (win.location.protocol.startsWith("http")) {
      // Interpret the path relative to that window's href. So the path
      // will acquire the protocol used by the window. And the less we
      // specify in `path`, the more it gets from the window. For
      // instance, if path is "/foo.js", then the host name will also be
      // acquired from the window's location.
      return new URL(path, win.location.href).toString();
    }

    // We searched all the way to the top and found nothing useful.
    if (win === win.parent) {
      break;
    }

    win = win.parent;
  }

  // I've got a big problem on my hands if there's nothing that works.
  throw new Error("cannot normalize the URL");
}