(function (window, document) {
    "use strict";

    const DEFAULT_DURATION = 7000;
    const VALID_TYPES = new Set(["success", "info", "warning", "danger"]);

    function getHost() {
        let host = document.getElementById("cygnus-notifications");
        if (!host) {
            host = document.createElement("div");
            host.id = "cygnus-notifications";
            host.className = "position-fixed top-0 start-50 translate-middle-x p-3";
            host.style.cssText = "z-index:1085;max-width:720px;width:calc(100% - 2rem)";
            host.setAttribute("aria-live", "polite");
            host.setAttribute("aria-atomic", "true");
            document.body.append(host);
        }
        return host;
    }

    function dismiss(alert) {
        const bootstrapAlert = window.bootstrap?.Alert;
        if (bootstrapAlert) {
            bootstrapAlert.getOrCreateInstance(alert).close();
        } else {
            alert.remove();
        }
    }

    function show(options) {
        const settings = options || {};
        const type = VALID_TYPES.has(settings.type) ? settings.type : "info";
        const host = getHost();
        const alert = document.createElement("div");
        alert.className = `alert alert-${type} alert-dismissible fade show shadow-sm`;
        alert.setAttribute("role", type === "danger" ? "alert" : "status");

        if (settings.code) {
            const code = document.createElement("strong");
            code.textContent = `${settings.code}: `;
            alert.append(code);
        }
        alert.append(document.createTextNode(settings.message || ""));

        if (settings.referenceId) {
            const reference = document.createElement("small");
            reference.className = "d-block mt-1";
            reference.textContent = `Reference: ${settings.referenceId}`;
            alert.append(reference);
        }

        if (settings.dismissible !== false) {
            const close = document.createElement("button");
            close.type = "button";
            close.className = "btn-close";
            close.setAttribute("aria-label", "Close");
            close.addEventListener("click", () => dismiss(alert));
            alert.append(close);
        }

        if (settings.stack === true) host.append(alert);
        else host.replaceChildren(alert);

        const duration = settings.duration === undefined ? DEFAULT_DURATION : settings.duration;
        if (Number.isFinite(duration) && duration > 0) {
            window.setTimeout(() => {
                if (alert.isConnected) dismiss(alert);
            }, duration);
        }
        return alert;
    }

    function clear() {
        document.getElementById("cygnus-notifications")?.replaceChildren();
    }

    window.CygnusNotifications = Object.freeze({ show, clear });
}(window, document));