'use strict';
// Unit tests for the Deezer metadata mapping/matching (backend/lib/deezer.js).
// Pure logic only — no network. Run: `node --test` from backend/ (or `npm test`).
// A live smoke test against api.deezer.com is included but only runs with RUN_LIVE=1.

const test = require('node:test');
const assert = require('node:assert/strict');
const dz = require('../lib/deezer');

// ── Fixtures: the exact Deezer shapes the mappers consume ─────────────────────
const ALBUM = {
  id: 302127,
  title: 'Discovery',
  cover_xl: 'https://img/cover_xl.jpg',
  cover_big: 'https://img/cover_big.jpg',
  release_date: '2001-03-07',
  nb_tracks: 14,
  record_type: 'album',
  genres: { data: [{ id: 113, name: 'Dance' }] },
  artist: { id: 27, name: 'Daft Punk' },
};
const TRACK = {
  id: 3135556,
  title: 'Harder, Better, Faster, Stronger',
  duration: 224,
  explicit_lyrics: false,
  preview: 'https://img/preview.mp3',
  artist: { id: 27, name: 'Daft Punk' },
};

test('mapAlbumTrack: numbers by album order and inherits album-level fields', () => {
  const item = dz.mapAlbumTrack(TRACK, ALBUM, 3); // 4th track
  assert.equal(item.wrapperType, 'track');
  assert.equal(item.kind, undefined);            // shape has no kind here; downloadAlbumTracks doesn't read it
  assert.equal(item.trackNumber, 4);             // index + 1 (Deezer album tracks carry no track_position)
  assert.equal(item.trackName, 'Harder, Better, Faster, Stronger');
  assert.equal(item.collectionName, 'Discovery');
  assert.equal(item.collectionArtistName, 'Daft Punk');
  assert.equal(item.primaryGenreName, 'Dance');
  assert.equal(item.releaseDate, '2001-03-07');
  assert.equal(item.trackCount, 14);
  assert.equal(item.trackTimeMillis, 224000);    // seconds → ms
  assert.equal(item.trackExplicitness, 'notExplicit');
  assert.equal(item.artworkUrl100, 'https://img/cover_xl.jpg');
});

test('mapAlbumTrack: per-track artist wins over the album artist (mixed-artist albums)', () => {
  const feat = { ...TRACK, artist: { id: 99, name: 'MeloMance' } };
  const item = dz.mapAlbumTrack(feat, ALBUM, 0);
  assert.equal(item.artistName, 'MeloMance');        // drives the per-track YTM search
  assert.equal(item.collectionArtistName, 'Daft Punk'); // album_artist stays stable → no album split
});

test('mapAlbumTrack: explicit flag maps through', () => {
  const item = dz.mapAlbumTrack({ ...TRACK, explicit_lyrics: true }, ALBUM, 0);
  assert.equal(item.trackExplicitness, 'explicit');
});

test('pickTrackMatch: strict match on artist + title', () => {
  const results = [
    { title: 'Some Other Song', artist: { name: 'Daft Punk' } },
    { title: 'Harder, Better, Faster, Stronger', artist: { name: 'Daft Punk' } },
  ];
  const m = dz.pickTrackMatch(results, 'Daft Punk', 'Harder, Better, Faster, Stronger');
  assert.equal(m, results[1]);
});

test('pickTrackMatch: title-only fallback for non-Japanese when artist differs', () => {
  const results = [{ title: 'Levitating', artist: { name: 'Some Cover Act' } }];
  const m = dz.pickTrackMatch(results, 'Dua Lipa', 'Levitating');
  assert.equal(m, results[0]); // ASCII title → title-only fallback allowed
});

test('pickTrackMatch: NO title-only fallback for Japanese titles', () => {
  const results = [{ title: '残酷な天使のテーゼ', artist: { name: 'Someone Else' } }];
  const m = dz.pickTrackMatch(results, '高橋洋子', '残酷な天使のテーゼ');
  assert.equal(m, null); // JP title + wrong artist must not match a same-titled cover
});

test('pickTrackMatch: Japanese title DOES match when the artist matches', () => {
  const results = [{ title: '残酷な天使のテーゼ', artist: { name: '高橋洋子' } }];
  const m = dz.pickTrackMatch(results, '高橋洋子', '残酷な天使のテーゼ');
  assert.equal(m, results[0]);
});

test('pickTrackMatch: leading aesthetic punctuation is ignored on the artist', () => {
  const results = [{ title: 'nostalgia', artist: { name: '.diedlonely' } }];
  const m = dz.pickTrackMatch(results, '.diedlonely', 'nostalgia');
  assert.equal(m, results[0]);
});

test('pickTrackMatch: empty / no match returns null', () => {
  assert.equal(dz.pickTrackMatch([], 'x', 'y'), null);
  assert.equal(dz.pickTrackMatch([{ title: 'A', artist: { name: 'B' } }], 'C', 'D'), null);
});

test('normalizeTitle: unifies variant suffixes and punctuation', () => {
  assert.equal(dz.normalizeTitle("don't rush - slowed"), dz.normalizeTitle("don't rush (slowed)"));
  assert.equal(dz.normalizeTitle('Mr. Lawrence'), dz.normalizeTitle('Mr Lawrence'));
});

// ── Live smoke test (opt-in): confirms the real Deezer shape still maps ────────
test('LIVE: lookupTrackMeta returns enriched fields', { skip: process.env.RUN_LIVE !== '1' }, async () => {
  const meta = await dz.lookupTrackMeta('Daft Punk', 'Harder, Better, Faster, Stronger');
  assert.ok(meta.album, 'album present');
  assert.ok(meta.genre, 'genre present');
  assert.ok(meta.year, 'year present');
  assert.ok(meta.durationMs > 0, 'duration present');
});