/**
 * A manga's `genre` field may hold multiple comma-separated genres
 * (e.g. "冒险, 恋爱, 魔幻"). This normalizes the raw string into a
 * deduped, trimmed list.
 */
export function parseGenres(raw: string): string[] {
  if (!raw) return [];
  const seen = new Set<string>();
  const out: string[] = [];
  for (const part of raw.split(",")) {
    const g = part.trim();
    if (!g) continue;
    if (seen.has(g)) continue;
    seen.add(g);
    out.push(g);
  }
  return out;
}

/**
 * Flatten all genres across a collection of manga into a sorted unique list.
 */
export function collectGenres(
  mangas: { genre: string }[]
): string[] {
  const seen = new Set<string>();
  for (const m of mangas) {
    for (const g of parseGenres(m.genre)) seen.add(g);
  }
  return [...seen].sort();
}