// ==UserScript==
// @name         Google digits
// @description  Press 1-9 on Google search page to open the corresponding link
// @include      https://www.google.tld/*
// @version      1.1.0
// @author       wOxxOm
// @namespace    wOxxOm.scripts
// @license      MIT License
// @run-at       document-start
// @grant        none
// @downloadURL none
// ==/UserScript==

(document.head || document.documentElement).appendChild(document.createElement('style')).textContent = '\
body {\
  counter-reset: digitnav;\
}\
#res a h3 {\
  counter-increment: digitnav;\
}\
#res a h3::before {\
  content: counter(digitnav);\
  position: absolute;\
  margin-left: -1em;\
}';

window.addEventListener('keydown', function(e) {
  var digit = e.keyCode - 48;
  if (digit >= 1 && digit <= 9 &&
      location.href.match(/[#&?]q=/) &&
      !e.altKey && !e.ctrlKey && !e.shiftKey && !e.metaKey &&
      e.target.localName != 'input') {
    var el = document.querySelectorAll('a h3')[digit - 1];
    var link = el && el.closest('a');
    if (link) {
      el.style.backgroundColor = 'yellow';
      location.href = link.href;
      e.preventDefault();
      e.stopPropagation();
      e.stopImmediatePropagation();
    }
  }
}, true);