import fs from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";
import midiPackage from "../frontend/node_modules/@tonejs/midi/build/Midi.js";

const { Midi } = midiPackage;
const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..", "backend", "sample_midi");
const expected = [
  ["starlight-steps-beginner.mid", 4],
  ["starlight-steps-easy.mid", 4],
  ["evening-waltz-beginner.mid", 3],
  ["sunrise-arpeggio-easy.mid", 4],
  ["black-key-pentatonic-beginner.mid", 4],
];

for (const [name, meter] of expected) {
  const midi = new Midi(fs.readFileSync(path.join(root, name)));
  const [right, left] = midi.tracks;
  if (midi.tracks.length !== 2 || !right?.notes.length || !left?.notes.length) {
    throw new Error(`${name}: 오른손과 왼손 트랙이 각각 필요합니다`);
  }
  if (midi.duration < 60 || midi.duration > 90) {
    throw new Error(`${name}: 곡 길이가 1분에서 1분 30초 사이여야 합니다 (${midi.duration.toFixed(1)}초)`);
  }
  if (midi.header.timeSignatures[0]?.timeSignature[0] !== meter) {
    throw new Error(`${name}: 박자가 일치하지 않습니다`);
  }
  if ([...right.notes, ...left.notes].some((note) => note.midi < 21 || note.midi > 108)) {
    throw new Error(`${name}: 피아노 음역을 벗어났습니다`);
  }
  console.log(`${name}: ${midi.duration.toFixed(1)}초, 오른손 ${right.notes.length}음, 왼손 ${left.notes.length}음`);
}