}
function ema(values, period) {
const k = 2 / (period + 1);
const out = Array(values.length).fill(null);
let prev;
for (let i = 0; i < values.length; i++) {
const v = values[i];
prev = (prev === undefined) ? v : (v - prev) * k + prev;
out[i] = prev;
}
return out;
}
async function load() {
const ticker = tickerEl.value.trim().toUpperCase() || 'AAPL';
let timespan = tfEl.value;
let multiplier = 1;
if (timespan === '5' || timespan === '15') { multiplier = parseInt(timespan, 10); timespan = 'minute'; }
const params = new URLSearchParams({
ticker,
multiplier: String(multiplier),
timespan,
from: fromEl.value,
to: toEl.value,
limit: '5000',
});
const barsResp = await fetch(`${WORKER_URL}/api/bars?${params.toString()}`);
const barsJson = await barsResp.json();
const results = Array.isArray(barsJson.results) ? barsJson.results : [];
const cdata = results.map(b => ({
time: Math.floor(b.t / 1000),
open: b.o, high: b.h, low: b.l, close: b.c,
}));
candleSeries.setData(cdata);
// Volume
const vdata = results.map(b => ({ time: Math.floor(b.t / 1000), value: b.v }));
volSeries.setData(vdata);
// Indicators
const closes = results.map(b => b.c);
const sma20 = sma(closes, 20).map((v, i) => v ? { time: Math.floor(results[i].t / 1000), value: v } : null).filter(Boolean);
const ema50 = ema(closes, 50).map((v, i) => v ? { time: Math.floor(results[i].t / 1000), value: v } : null).filter(Boolean);
sma20Series.setData(sma20);
ema50Series.setData(ema50);
sma20Series.applyOptions({ visible: sma20El.checked });
ema50Series.applyOptions({ visible: ema50El.checked });
// Quote snapshot
const snapResp = await fetch(`${WORKER_URL}/api/snapshot?ticker=${ticker}`);
const snap = await snapResp.json();
if (snap && snap.ticker) {
const q = snap.ticker;
const last = q.lastTrade?.p ?? '—';
const bid = q.lastQuote?.p ?? '—';
const ask = q.lastQuote?.P ?? '—';
quoteEl.innerHTML = `${ticker}
Last: ${last}
Bid: ${bid} / Ask: ${ask}
`;
} else {
quoteEl.textContent = '—';
}
}
loadBtn.addEventListener('click', load);
sma20El.addEventListener('change', () => sma20Series.applyOptions({ visible: sma20El.checked }));
ema50El.addEventListener('change', () => ema50Series.applyOptions({ visible: ema50El.checked }));
// Initial load
load();
// Handle resize
const fit = () => {
chart.timeScale().fitContent();
subChart.timeScale().fitContent();
};
window.addEventListener('resize', fit);