// /home/def/monitor/backend/providers/klingex.js
//
// Minimal KlingEx provider used ONLY for ETHO and EGAZ (spot price).
// We intentionally do NOT try to use KlingEx for all assets.
// This provider returns a consistent shape expected by server.js:
//
//   { price: <number>, points: [], source: 'klingex:sdk' }
//
// Pair input accepted as "ETHO-USDT" or "ETHO_USDT" (case-insensitive).

const { KlingEx } = require("klingex");

let client = null;
async function getClient() {
  if (client) return client;
  client = new KlingEx(); // public endpoints work without auth for markets/tickers
  return client;
}

function normalizePair(pair) {
  const p = String(pair || "").trim().toUpperCase().replace("_", "-");
  const m = p.match(/^([A-Z0-9]+)-([A-Z0-9]+)$/);
  if (!m) return null;
  return { base: m[1], quote: m[2], dash: `${m[1]}-${m[2]}`, underscore: `${m[1]}_${m[2]}` };
}

async function fetchPair(pair) {
  const norm = normalizePair(pair);
  if (!norm) throw new Error(`Bad klingex_pair: ${pair}`);

  const kx = await getClient();

  // KlingEx SDK: client.markets.tickers() -> array of tickers like:
  // { ticker_id: 'ETHO_USDT', last_price: '0.005', ... }  (or sometimes integer-ish strings)
  const tickers = await kx.markets.tickers();

  if (!Array.isArray(tickers)) {
    throw new Error(`KlingEx tickers() returned non-array`);
  }

  const t = tickers.find(x => String(x?.ticker_id || "").toUpperCase() === norm.underscore);
  if (!t) {
    throw new Error(`KlingEx: pair not found in tickers(): ${norm.underscore}`);
  }

  // Prefer last_price. Some exchanges also provide "last" etc, but your data uses last_price.
  const raw = t.last_price ?? t.last ?? t.price ?? null;
  const price = raw != null ? Number(raw) : NaN;

  if (!isFinite(price)) {
    throw new Error(`KlingEx: non-numeric last_price for ${norm.underscore}: ${String(raw)}`);
  }

  return {
    price,          // <-- server.js expects r.price
    points: [],     // no OHLCV implemented yet
    source: "klingex:sdk"
  };
}

module.exports = { fetchPair };