(function () {
    var timer = null;

    function fmtDist(v) {
        if (v === null || v === undefined) return '--';
        return v.toFixed(2);
    }

    function pollPrices() {
        var list = document.getElementById('key-monitor-list');
        if (!list || !list.querySelector('.key-item')) return;

        fetch('/api/key_prices')
            .then(function (r) { return r.json(); })
            .then(function (rows) {
                rows.forEach(function (row) {
                    var el = list.querySelector('.key-item[data-key-id="' + row.id + '"]');
                    if (!el) return;
                    var priceEl = el.querySelector('.live-price');
                    var upEl = el.querySelector('.dist-up');
                    var downEl = el.querySelector('.dist-down');
                    if (priceEl) {
                        priceEl.textContent = row.price != null ? row.price : '--';
                    }
                    if (upEl) upEl.textContent = fmtDist(row.dist_upper);
                    if (downEl) downEl.textContent = fmtDist(row.dist_lower);
                });
            })
            .catch(function () { /* ignore */ });
    }

    function startPolling() {
        if (timer) clearInterval(timer);
        pollPrices();
        timer = setInterval(pollPrices, 1000);
    }

    document.addEventListener('DOMContentLoaded', startPolling);
})();