// ============================================================
// ANALYZE BTC TREND — EMA9/21/50 + RSI14 + ROC5
// ============================================================

function ema(closes, period) {
  if (closes.length < period) return closes[closes.length - 1] || 0;
  const k = 2 / (period + 1);
  let val = closes.slice(0, period).reduce((s, v) => s + v, 0) / period;
  for (let i = period; i < closes.length; i++) val = closes[i] * k + val * (1 - k);
  return val;
}
function rsiCalc(closes, period) {
  if (closes.length < period + 1) return 50;
  const slice = closes.slice(-(period + 1));
  let g = 0, l = 0;
  for (let i = 1; i < slice.length; i++) {
    const d = slice[i] - slice[i - 1];
    d >= 0 ? (g += d) : (l -= d);
  }
  const ag = g / period, al = l / period;
  return al === 0 ? 100 : 100 - 100 / (1 + ag / al);
}

const allBtcItems = $input.all();
let klines;
if (allBtcItems.length > 1) {
  klines = allBtcItems.map(item => {
    const v = item.json;
    return Array.isArray(v) ? v : Object.values(v);
  });
} else {
  const rawInput = allBtcItems[0].json;
  if (Array.isArray(rawInput) && Array.isArray(rawInput[0])) {
    klines = rawInput;
  } else if (Array.isArray(rawInput)) {
    klines = rawInput.length > 0 && !Array.isArray(rawInput[0]) ? [rawInput] : rawInput;
  } else {
    klines = [];
  }
}

if (klines.length < 22) {
  return [{ json: { btcSignal: { trend: 'neutral', score: 0, ema9: 0, ema21: 0, ema50: 0, rsi: 50, roc5: 0, dataOk: false } } }];
}

const closes = klines.map(k => parseFloat(k[4]));
const n = closes.length;
const price = closes[n - 1];

const EMA9  = ema(closes, 9);
const EMA21 = ema(closes, 21);
const EMA50 = ema(closes, Math.min(50, closes.length));
const RSI   = rsiCalc(closes, 14);
const roc5  = closes[n - 6] > 0 ? +((price - closes[n - 6]) / closes[n - 6] * 100).toFixed(4) : 0;

let score = 0;
if (EMA9 > EMA21)  score += 0.5; else if (EMA9 < EMA21)  score -= 0.5;
if (price > EMA50) score += 0.5; else if (price < EMA50) score -= 0.5;
if (RSI >= 55)     score += 0.5; else if (RSI <= 45)      score -= 0.5;
if (roc5 >= 0.3)   score += 0.5; else if (roc5 <= -0.3)   score -= 0.5;
score = +score.toFixed(2);

const trend = score >= 1.0 ? 'bull' : score <= -1.0 ? 'bear' : 'neutral';

return [{ json: { btcSignal: { trend, score, ema9: +EMA9.toFixed(2), ema21: +EMA21.toFixed(2), ema50: +EMA50.toFixed(2), rsi: +RSI.toFixed(1), roc5, price: +price.toFixed(2), dataOk: true } } }];