// volterra.js — the whole read this page performs.
// nothing here is private. paste it into a console and you
// get the same predator/prey call this page shows.

const N      = 240;   // window: 240 one-minute candles (4h)
const MAXLAG = 60;    // search lead-lag across ±60 minutes

// 1. last N one-minute closes for one coin, from hyperliquid's
//    public info endpoint — the same request a bot would make.
async function fetchSeries(coin) {
  const now = Date.now();
  const r = await fetch('https://api.hyperliquid.xyz/info', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ type: 'candleSnapshot', req: {
      coin, interval: '1m', startTime: now - N*60*1000, endTime: now } }),
  });
  return (await r.json()).map(c => Number(c.c));
}

// 2. detrend each price into a population that oscillates around
//    its own EMA baseline, then z-score it. removes the secular
//    trend so what's left is the predator-prey swing.
function detrendZ(arr, halflife = 60) {
  const log = arr.map(p => Math.log(p));
  const k = Math.exp(-Math.log(2) / halflife);
  const ema = [log[0]];
  for (let i = 1; i < log.length; i++)
    ema.push(k*ema[i-1] + (1-k)*log[i]);
  const dev = log.map((x,i) => x - ema[i]);
  const m = dev.reduce((a,b)=>a+b,0)/dev.length;
  const s = Math.sqrt(dev.reduce((a,b)=>a+(b-m)**2,0)/dev.length) || 1e-9;
  return dev.map(x => (x-m)/s);
}

// 3. lagged cross-correlation. C(tau) = corr(HYPE[t], SOL[t-tau]).
//    tau>0 means SOL's past predicts HYPE's present: SOL LEADS,
//    HYPE LAGS — so HYPE is the predator. tau<0 flips it.
function crossCorr(h, s, maxLag) {
  const out = [];
  for (let tau = -maxLag; tau <= maxLag; tau++) {
    let num = 0, n = 0;
    for (let t = 0; t < h.length; t++) {
      const j = t - tau;
      if (j >= 0 && j < s.length) { num += h[t]*s[j]; n++; }
    }
    out.push({ tau, c: n ? num / n : 0 });
  }
  return out;
}

// 4. compose. the peak of |C| names predator + pressure.
const H = detrendZ(await fetchSeries('HYPE'));
const S = detrendZ(await fetchSeries('SOL'));
const spec = crossCorr(H, S, MAXLAG);
const peak = spec.reduce((a,b) => Math.abs(b.c) > Math.abs(a.c) ? b : a);

// peak.tau > 0  → HYPE is the predator (it lags, it feeds)
// peak.tau < 0  → SOL  is the predator
// |peak.c|      → predation pressure, 0..1 → 0..100