steam-usd-tl-ceviricisi.js

// ==UserScript==
// @name Steam USD/TL Çeviricisi
// @namespace http://tampermonkey.net/
// @author Kemal Ersin YILMAZ
// @icon http://store.steampowered.com/favicon.ico
// @match http://store.steampowered.com/*
// @match https://store.steampowered.com/*
// @run-at document-body
// @grant GM.xmlHttpRequest
// ==/UserScript==
/* jshint -W097 */

(async function() {
    'use strict';

    var request = await GM.xmlHttpRequest({
        url: 'https://api.genelpara.com/embed/doviz.json'
    });

    if (!request.response) {
        return;
    }

    var json = JSON.parse(request.response);

    if (!json.USD) {
        return;
    }

    var usdRate = json.USD.satis;

    var regex = /\$([0-9,]+\.\d{2})\s*(USD)?/;
    var elements = document.querySelectorAll('.discount_final_price, .game_purchase_price, .game_area_dlc_price, .your_price div');

    if (!elements.length) {
        return;
    }

    elements.forEach(function(element) {
        var match = element.textContent.match(regex);

        if (match) {
            var usdPrice = parseFloat(match[1]);
            var multipliedPrice = usdPrice * usdRate;

            var formattedMultipliedPrice = multipliedPrice.toLocaleString('tr-TR', {
                style: 'currency',
                currency: 'TRY'
            });

            element.textContent += ` (${formattedMultipliedPrice})`;
        }
    });
})();