Normalising Genres Across Spotify, Beatport, and Discogs

const API_KEY = process.env.SONOVAULT_API_KEY!;
const BASE    = "https://api.sonovault.now/v1";

interface Genre      { id: number; name: string; type: "main" | "subgenre"; parent: string | null; }
interface Hierarchy  { mains: string[]; subsByMain: Record<string, string[]>; }

async function buildHierarchy(): Promise<Hierarchy> {
  const res = await fetch(`${BASE}/genres`, {
    headers: { "x-api-key": API_KEY },
  });
  const { genres }: { genres: Genre[] } = await res.json();

  const mains      = genres.filter(g => g.type === "main").map(g => g.name);
  const subsByMain: Record<string, string[]> = {};

  for (const g of genres) {
    if (g.type === "subgenre" && g.parent) {
      (subsByMain[g.parent] ??= []).push(g.name);
    }
  }
  return { mains, subsByMain };
}

const tree = await buildHierarchy();
console.log(`${tree.mains.length} main genres, ${
  Object.values(tree.subsByMain).flat().length
} subgenres`);

// Same track via two different sources — same canonical taxonomy.

// Spotify-flavoured ISRC:
{
  "id": 123,
  "title": "One More Time",
  "genre":     ["House"],
  "subgenre":  ["French House"]
}

// Beatport-flavoured ISRC:
{
  "id": 123,
  "title": "One More Time",
  "genre":     ["House"],
  "subgenre":  ["French House"]
}

// Map a mixed-source library to the canonical taxonomy.
// Input rows already have ISRC (see the cross-platform backfill article).

interface LibraryRow { id: string; isrc: string; source_genre: string; }
interface NormalisedRow { id: string; main: string[]; sub: string[]; }

async function resolveBatch(isrcs: string[]) {
  const res = await fetch(`${BASE}/tracks/resolve`, {
    method:  "POST",
    headers: { "x-api-key": API_KEY, "content-type": "application/json" },
    body:    JSON.stringify({ input_type: "isrc", items: isrcs }),
  });
  return (await res.json()).results;
}

const out: NormalisedRow[] = [];
const BATCH = 100;

for (let i = 0; i < rows.length; i += BATCH) {
  const chunk   = rows.slice(i, i + BATCH);
  const results = await resolveBatch(chunk.map(r => r.isrc));

  chunk.forEach((row, j) => {
    const track = results[j]?.track;
    if (!track) return;
    out.push({
      id:   row.id,
      main: track.genre    ?? [],
      sub:  track.subgenre ?? [],
    });
  });
}

console.log(`Normalised ${out.length} / ${rows.length} rows`);