window.addEventListener("DOMContentLoaded", function () {
    var injected = false;

    var observer = new MutationObserver(function () {
        // Rename if Mattermost ever renders the GitLab button natively
        document.querySelectorAll("a[href*='/oauth/gitlab/']").forEach(function (el) {
            if (el.textContent.trim() === "GitLab") {
                el.textContent = "SSO with {{ SOFTWARE_NAME }}";
            }
        });

        // Inject SSO button when login form is present but no native SSO button rendered
        if (injected) return;
        if (!document.getElementById("input_loginId")) return;
        if (document.querySelector("a[href*='/oauth/gitlab/']")) return;

        var btn = document.getElementById("saveSetting");
        if (!btn) return;

        var a = document.createElement("a");
        a.href = "/oauth/gitlab/login";
        a.textContent = "SSO with {{ SOFTWARE_NAME }}";
        a.className = "btn btn-primary login-body-card-form-button-submit large";
        a.style.cssText = "display:flex;align-items:center;justify-content:center;width:100%;box-sizing:border-box;margin:20px 0 0 0;";
        btn.parentNode.insertBefore(a, btn.nextSibling);
        injected = true;
    });

    observer.observe(document.body, { childList: true, subtree: true });
});