// tools/test_midi_polyphony.js — runnable check cho Phase A (dedup/legato/polyphony).
// Đọc app.jsx, extract 2 hàm thuần, eval, assert spec §II.1 + §II.5.
const fs = require('fs');
const path = require('path');
const src = fs.readFileSync(path.join(__dirname, '..', 'app', 'static', 'js', 'app.jsx'), 'utf8');

const start = src.indexOf('const _cleanNativeNotes = (notes) => {');
const end = src.indexOf('const _nativeTrackKey', start);
if (start < 0 || end < 0) { console.error('FAIL: khong tim thay 2 ham'); process.exit(1); }
const code = src.slice(start, end) +
  ';globalThis._cleanNativeNotes=_cleanNativeNotes;' +
  'globalThis._scaleNativePolyphony=_scaleNativePolyphony;';
// eslint-disable-next-line no-eval
(0, eval)(code); // indirect eval: const khai báo ở global scope

let fails = 0;
const assert = (cond, msg) => { if (!cond) { fails++; console.error('FAIL: ' + msg); } else { console.log('ok: ' + msg); } };
const near = (a, b, eps) => Math.abs(a - b) < (eps || 1e-9);

// 1. 8-note chord cùng lúc → tổng peak ≈ 0.3*8/sqrt(8) ≤ 1.0
const chord = [];
for (let i = 0; i < 8; i++) chord.push({ pitch: 60 + i, start_beat: 0, duration_beats: 2, velocity: 0.3 });
const sc = _scaleNativePolyphony(_cleanNativeNotes(chord));
const sum = sc.reduce((a, n) => a + n.velocity, 0);
assert(sc.length === 8, 'chord giu 8 note');
assert(near(sum, 8 * 0.3 / Math.sqrt(8)), 'tong peak ' + sum.toFixed(4) + ' ~= ' + (8 * 0.3 / Math.sqrt(8)).toFixed(4));
assert(sum <= 1.0, 'tong peak <= 1.0');

// 2. Solo → giữ nguyên velocity
const solo = _scaleNativePolyphony([{ pitch: 60, start_beat: 0, duration_beats: 1, velocity: 0.8 }]);
assert(near(solo[0].velocity, 0.8), 'solo velocity giu nguyen 0.8');

// 3. Dedup: cùng pitch + start_beat → gộp, velocity max
const dup = _cleanNativeNotes([
  { pitch: 60, start_beat: 1, duration_beats: 2, velocity: 0.5 },
  { pitch: 60, start_beat: 1, duration_beats: 3, velocity: 0.7 },
]);
assert(dup.length === 1, 'dedup gop 2 note');
assert(near(dup[0].velocity, 0.7), 'dedup giu velocity cao 0.7');
assert(near(dup[0].duration_beats, 3), 'dedup giu duration dai nhat');

// 4. Legato: note trước cắt 0.01 beats trước note sau cùng pitch
const leg = _cleanNativeNotes([
  { pitch: 60, start_beat: 0, duration_beats: 4, velocity: 0.8 },
  { pitch: 60, start_beat: 2, duration_beats: 1, velocity: 0.8 },
]);
assert(leg.length === 2, 'legato giu 2 note');
assert(near(leg[0].duration_beats, 2 - 0.01, 1e-6), 'note dau cat con ' + leg[0].duration_beats);
assert(near(leg[1].duration_beats, 1), 'note sau giu nguyen');

// 5. Nối tiếp khác pitch → không cắt
const seq = _cleanNativeNotes([
  { pitch: 60, start_beat: 0, duration_beats: 4, velocity: 0.8 },
  { pitch: 64, start_beat: 2, duration_beats: 1, velocity: 0.8 },
]);
assert(near(seq[0].duration_beats, 4), 'khac pitch khong bi cat');

console.log(fails ? 'FAILED: ' + fails : 'ALL PASS');
process.exit(fails ? 1 : 0);