Amazon Force Currency Selector (Interactive)

Forces the currency on Amazon and asks which currency to display, works on all Amazon domains

Aby zainstalować ten skrypt, wymagana jest instalacje jednego z następujących rozszerzeń: Tampermonkey, Greasemonkey lub Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

Aby zainstalować ten skrypt, wymagana jest instalacje jednego z następujących rozszerzeń: Tampermonkey, Violentmonkey.

Aby zainstalować ten skrypt, wymagana będzie instalacja rozszerzenia Tampermonkey lub Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

Aby zainstalować ten skrypt, musisz zainstalować rozszerzenie menedżera skryptów użytkownika.

(Mam już menedżera skryptów użytkownika, pozwól mi to zainstalować!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

Będziesz musiał zainstalować rozszerzenie menedżera stylów użytkownika, aby zainstalować ten styl.

Będziesz musiał zainstalować rozszerzenie menedżera stylów użytkownika, aby zainstalować ten styl.

Musisz zainstalować rozszerzenie menedżera stylów użytkownika, aby zainstalować ten styl.

(Mam już menedżera stylów użytkownika, pozwól mi to zainstalować!)

// ==UserScript==
// @name         Amazon Force Currency Selector (Interactive)
// @namespace    https://amazon.com/
// @version      1.1
// @license      MIT
// @description  Forces the currency on Amazon and asks which currency to display, works on all Amazon domains
// @match        https://*.amazon.*/*
// @run-at       document-start
// ==/UserScript==

(function() {
    // --- 1. Ask user for desired currency at page load ---
    let FORCED_CURRENCY = localStorage.getItem("amazonForcedCurrency");
    if (!FORCED_CURRENCY) {
        FORCED_CURRENCY = prompt("Enter your desired Amazon currency code (e.g., USD, COP, BRL, EUR):", "COP");
        if (FORCED_CURRENCY) {
            FORCED_CURRENCY = FORCED_CURRENCY.toUpperCase();
            localStorage.setItem("amazonForcedCurrency", FORCED_CURRENCY);
        } else {
            // Default to COP if user cancels
            FORCED_CURRENCY = "COP";
        }
    }

    const paramName = "currency";

    // List of main Amazon domains
    const AMAZON_DOMAINS = [
        ".amazon.com",
        ".amazon.com.br",
        ".amazon.com.mx",
        ".amazon.ca",
        ".amazon.co.uk",
        ".amazon.de",
        ".amazon.fr",
        ".amazon.it",
        ".amazon.es",
        ".amazon.in",
        ".amazon.co.jp",
        ".amazon.com.au"
    ];

    // --- 2. Force currency cookies every 500ms ---
    function forceCookies() {
        AMAZON_DOMAINS.forEach(domain => {
            document.cookie = `currencyPreference=${FORCED_CURRENCY}; path=/; domain=${domain}`;
            document.cookie = `i18n-prefs=${FORCED_CURRENCY}; path=/; domain=${domain}`;
        });
    }
    setInterval(forceCookies, 500);

    // --- 3. Rewrite any URL to include ?currency=YOUR_CURRENCY ---
    function ensureURLHasCurrency(url) {
        try {
            let u = new URL(url, location.href);
            if (u.searchParams.get(paramName) !== FORCED_CURRENCY) {
                u.searchParams.set(paramName, FORCED_CURRENCY);
            }
            return u.toString();
        } catch (e) {
            return url;
        }
    }

    // Modify all links on the page
    function fixLinks() {
        document.querySelectorAll("a[href]").forEach(a => {
            if (!a.__fixedCurrency) {
                a.href = ensureURLHasCurrency(a.href);
                a.__fixedCurrency = true;
            }
        });
    }
    document.addEventListener("DOMContentLoaded", fixLinks);
    document.addEventListener("mouseover", fixLinks);
    document.addEventListener("click", fixLinks);

    // --- 4. Intercept SPA URL changes ---
    const pushState = history.pushState;
    history.pushState = function() {
        arguments[2] = ensureURLHasCurrency(arguments[2]);
        return pushState.apply(this, arguments);
    };
    window.addEventListener("popstate", () => {
        if (!location.search.includes(`${paramName}=${FORCED_CURRENCY}`)) {
            location.replace(ensureURLHasCurrency(location.href));
        }
    });

    // --- 5. Intercept fetch/XHR to block Amazon attempts to change currency ---
    function interceptURL(original) {
        return function(url, ...rest) {
            return original.call(this, ensureURLHasCurrency(url), ...rest);
        };
    }
    window.fetch = interceptURL(window.fetch);

    const open = XMLHttpRequest.prototype.open;
    XMLHttpRequest.prototype.open = function(method, url, ...rest) {
        return open.call(this, method, ensureURLHasCurrency(url), ...rest);
    };

})();