document.querySelectorAll(".gx-select").forEach(select => {
    const trigger = select.querySelector(".gx-select-trigger");
    const menu = select.querySelector(".gx-select-menu");
    const valueElement = select.querySelector(".gx-select-value");
    const items = menu.querySelectorAll(".gx-select-item");

    let open = false;
    let index = -1;

    /* OPEN/CLOSE */
    trigger.addEventListener("click", () => toggleMenu());

    function toggleMenu() {
        open = !open;
        select.classList.toggle("open", open);

        if (open) {
            index = -1;
            positionMenu();
        }
    }

    /* SMART POSITIONING */
    function positionMenu() {
        const rect = menu.getBoundingClientRect();
        if (rect.bottom > window.innerHeight) {
            menu.style.top = "auto";
            menu.style.bottom = "calc(100% + 6px)";
        }
    }

    /* ITEM CLICK */
    items.forEach((item, i) => {
        item.addEventListener("click", () => {
            items.forEach(i => i.classList.remove("selected"));
            item.classList.add("selected");
            valueElement.textContent = item.textContent;

            select.dataset.value = item.dataset.value;
            toggleMenu();
        });
    });

    /* CLICK OUTSIDE */
    document.addEventListener("click", e => {
        if (!select.contains(e.target)) {
            select.classList.remove("open");
            open = false;
        }
    });

    /* KEYBOARD NAVIGATION */
    trigger.addEventListener("keydown", e => {
        if (!open && (e.key === "ArrowDown" || e.key === "Enter")) {
            toggleMenu();
            return;
        }

        if (!open) return;

        if (e.key === "ArrowDown") {
            index = (index + 1) % items.length;
            highlight();
        } else if (e.key === "ArrowUp") {
            index = (index - 1 + items.length) % items.length;
            highlight();
        } else if (e.key === "Enter") {
            if (index >= 0) items[index].click();
        } else if (e.key === "Escape") {
            toggleMenu();
        }
    });

    function highlight() {
        items.forEach(i => i.classList.remove("selected"));
        if (index >= 0) items[index].classList.add("selected");
    }
});