// ==UserScript==
// @name         DDG-like Vim keybindings for Ecosia
// @namespace    https://gist.github.com/tycho01/f5d319a89d0c21ebcdae94f68b6bf604
// @version      0.01
// @description  plants trees while navigating search results by keyboard!
// @author       tycho01
// @match        https://www.ecosia.org/search?q=*
// @grant        none
// @esversion   6
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    const get_res = i => document.getElementsByClassName('result')[i];

    var hit = -1; // global

    function select_hit(next = true) {
        const el_ = get_res(hit);
        if(el_) el_.classList.remove("highlight");
        hit = Math.max(0, next ? hit + 1 : hit - 1);
        const el = get_res(hit);
        el.classList.add("highlight");
        el.getElementsByTagName("a")[0].focus();
        var y = window.scrollY + el.getBoundingClientRect().top;
        window.scroll({ top: y, behavior: 'smooth' });
    }

    document.addEventListener('keydown', function(event) {
        const code = event.keyCode;
        if (code == 13) { // enter
            get_res(hit).click();
        }
        // if not in the search box
        if (code == 40 || code == 74) { // down / j
            event.preventDefault();
            select_hit(true);
        }
        if (code == 38 || code == 75) { // up / k
            event.preventDefault();
            select_hit(false);
        }
    });

    // define css class
    var style = document.createElement('style');
    style.type = 'text/css';
    style.innerHTML = '.highlight { background-color: rgba(220, 220, 255, 0.1); }';
    document.getElementsByTagName('head')[0].appendChild(style);
})();