Access to fetch at 'https://loyce.club/trust/latestversion.txt' from origin 'https://bitcointalk.org' has been blocked by
CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your
needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

// ==UserScript==
// @name         Loyce Trust List Viewer Button
// @version      0.1
// @description  adds a button under each user's profile with the latest link to Loyce's Trust Viewer list.
// @author       TryNinja
// @match        https://bt.irlbtc.com/view/*
// @match        https://bitcointalk.org/index.php?action=profile;u=*
// @grant        none
// @credits      A big part of the code was taken (copy-pasted and modified) from BPIP's extension. https://bt.irlbtc.com/view/5224821.0
// ==/UserScript==

(function() {
    const MAX_VALID_USER_ID = 1500000000;
    const PROFILE_URL_PREFIX = "https://bitcointalk.org/index.php?action=profile;u=";
    const LOYCE_TRUST_LAST_VERSION_URL = "https://loyce.club/trust/latestversion.txt";

    let LOYCE_TRUST_URL;
    let LOYCE_TRUST_URL_PROFILE;
    let LOYCE_TRUST_PROFILE_BUTTON_HTML;

    function injectLoyceTrustButtons() {
        LOYCE_TRUST_URL_PROFILE = LOYCE_TRUST_URL + "%%USERID%%.html";
        LOYCE_TRUST_PROFILE_BUTTON_HTML = '<a href="' + LOYCE_TRUST_URL_PROFILE + '" target="_blank"><img src="https://talkimg.com/images/2023/05/14/blobf2a1ef7d63fd727a.png" style="width: 16px; height: 16px;" title="Loyce\'s Trust Viewer"></a>';

        if (window.location.href.startsWith(PROFILE_URL_PREFIX)) {
            const user_id = window.location.href.replace(PROFILE_URL_PREFIX, "");
            const user_name_cell = document.querySelector("tr.titlebg ~ tr td.windowbg table tr").lastElementChild;
            LOYCE_TRUST_PROFILE_BUTTON_HTML = LOYCE_TRUST_PROFILE_BUTTON_HTML.replace("%%USERID%%", user_id);
            setTimeout(() => {
                user_name_cell.innerHTML = user_name_cell.innerHTML + " " + LOYCE_TRUST_PROFILE_BUTTON_HTML;
            }, 50)
        } else {
            document.querySelectorAll("img[title='View Profile']")
                .forEach(img => {
                    let profile_box = img.parentElement.parentElement.parentElement;
                    let user_name_link = profile_box.querySelector("b > a");
                    let profile_link = profile_box.querySelector("div.smalltext a[href*='action=profile']");
                    if (user_name_link && profile_link) {
                        let user_id = user_name_link.getAttribute("href")
                            .replace(PROFILE_URL_PREFIX, "");
                        if (user_id > MAX_VALID_USER_ID) {
                            return;
                        }
                        const loyceTrustProfileFullURL = LOYCE_TRUST_URL_PROFILE.replace("%%USERID%%", user_id);

                        const loyceTrustButtonElement = document.createElement("a");
                        loyceTrustButtonElement.setAttribute('href', loyceTrustProfileFullURL);
                        loyceTrustButtonElement.setAttribute('target', '_blank');

                        const loyceTrustButtonImageElement = document.createElement("img");
                        loyceTrustButtonImageElement.setAttribute('src', 'https://talkimg.com/images/2023/05/14/blobf2a1ef7d63fd727a.png');
                        loyceTrustButtonImageElement.setAttribute('style', 'width: 16px; height: 16px;');
                        loyceTrustButtonImageElement.setAttribute('title', 'Loyce\'s Trust Viewer');

                        loyceTrustButtonElement.appendChild(loyceTrustButtonImageElement);
                        profile_link.before(loyceTrustButtonElement);
                    }
                });
        }
    }

    function getLatestLoyceTrustURL() {
        let cached = JSON.parse(localStorage.getItem('@btt-ninja-cache/loyce-trust-link'));

        if (!cached) {
            fetch(LOYCE_TRUST_LAST_VERSION_URL)
                .then((response) => response.text())
                .then(data => {
                    LOYCE_TRUST_URL = data;
                    cached = {
                        last_url: data,
                        time: Date.now()
                    };
                    localStorage.setItem('@btt-ninja-cache/loyce-trust-link', JSON.stringify(cached));
                    injectLoyceTrustButtons();
                });
        } else {
            LOYCE_TRUST_URL = cached.last_url;
            const oneHourAgo = Date.now() - 1000 * 60 * 60;

            if (cached.time < oneHourAgo) {
                localStorage.setItem('@btt-ninja-cache/loyce-trust-link', null);
            }

            injectLoyceTrustButtons();
        }
    }

    getLatestLoyceTrustURL();
})();

<Files "latestversion.txt">
  Header set Access-Control-Allow-Origin "https://bitcointalk.org"
</Files>