import { NextRequest, NextResponse } from "next/server";
import { searchSongs as searchSongsDB, upsertSong } from "@/lib/db/client";
import { searchSongs as searchMB } from "@/lib/musicbrainz/client";
import { z } from "zod";

const QuerySchema = z.object({
  q: z.string().min(1).max(200),
  limit: z.coerce.number().int().min(1).max(50).default(20),
});

export async function GET(req: NextRequest) {
  const params = Object.fromEntries(req.nextUrl.searchParams);
  const parsed = QuerySchema.safeParse(params);

  if (!parsed.success) {
    return NextResponse.json(
      { error: "Invalid query parameters", details: parsed.error.flatten() },
      { status: 400 }
    );
  }

  const { q, limit } = parsed.data;

  // Try local DB first
  let songs = await searchSongsDB(q, limit);

  // Augment from MusicBrainz when local results are thin
  if (songs.length < 3) {
    try {
      const mbResults = await searchMB(q, limit);
      for (const s of mbResults) {
        await upsertSong({
          mbid: s.mbid,
          title: s.title,
          artist: s.artist,
          duration_seconds: s.duration_seconds,
          acousticbrainz_bpm: null,
          acousticbrainz_time_sig_num: null,
          source: "musicbrainz",
        });
      }
      songs = await searchSongsDB(q, limit);
    } catch (err) {
      console.error("[songs] MusicBrainz search failed:", err);
    }
  }

  return NextResponse.json({ songs, total: songs.length });
}