// ==UserScript==
// @name         Backpack.tf Keyboard Navigator
// @version      1.04
// @description  Allows for the use of the left and right keyboard keys to navigate backpack.tf classifieds and premium search pages.
// @author       Matt-RJ
// @include      /https?://(www\.)?backpack\.tf/.+/
// @namespace https://greasyfork.org/users/313414
// @downloadURL none
// ==/UserScript==

let openingNewPage = false;
let isFirstPage;
let isLastPage;

window.onkeydown = (e) => {

    const prevButton = document.getElementsByClassName('fa fa-angle-left')[0];
    const nextButton = document.getElementsByClassName('fa fa-angle-right')[0];

    try {
        isFirstPage = prevButton.parentElement.parentElement.className == "disabled";
        isLastPage = nextButton.parentElement.parentElement.className == "disabled";
    }
    catch(error) {
        return;
    }

    if (!openingNewPage) {
        if (e.keyCode === 37) { // Left arrow press
            if (prevButton && !isFirstPage) {
                console.log("Opening previous page...");
                prevButton.click();
                openingNewPage = true;
            }
        }

        else if (e.keyCode === 39) { // Right arrow press
            if (nextButton && !isLastPage) {
                console.log("Opening next page...");
                nextButton.click();
                openingNewPage = true;
            }
        }
    }
};