/* 对拍数据：JS 侧 fk / orient / gapMatrix / 特征（ik-policy.js）→ ml/data/parity.json
 *   node ml/eval/dump_parity.cjs [N=2000]
 * 然后 python -m ml.eval.check_parity 比对 PyTorch 版。 */
'use strict';
const fs = require('fs'), path = require('path');
const N = +process.argv[2] || 2000;
const { S } = require('../../tests/route_bench_setup.cjs')();
const POL = require('../../webapp/js/ik-policy.js');
const L = S.LIM, O = S.ORDER;
let st = 99; const rnd = () => { st = (st * 1664525 + 1013904223) >>> 0; return st / 4294967296; };
const rq = () => O.map(id => L[id].lo + rnd() * (L[id].hi - L[id].lo));
const recs = [];
for (let n = 0; n < N; n++) {
  const q = rq(), qp = q.map((v, i) => v - (rnd() - 0.5) * 2);
  const b = rq(); const T = S.fk(b, 0); const pose = rnd() < 0.5; const R = pose ? S.orient(b) : null;
  const r = Math.floor(rnd() * 4); const prefix = []; for (let k = 0; k < r; k++) prefix.push(q.map(() => (rnd() - 0.5) * 2));
  const sub = rnd() < 0.5 ? rq() : null;
  const st0 = { q, qPrev: qp, T, R, prefix, sub };
  const f = POL.features(S, st0);
  recs.push({ q, qPrev: qp, T, R, prefix, sub, fk: S.fk(q, 0), orient: S.orient(q), gm: Array.from(S.gapMatrix(q, 40)), feat: Array.from(f) });
}
const out = path.join(__dirname, '../data/parity.json');
fs.mkdirSync(path.dirname(out), { recursive: true });
fs.writeFileSync(out, JSON.stringify({ fp: S.modelFingerprint(), recs }));
console.log('wrote', out, recs.length);