import mongoose from 'mongoose';
import Track from '../models/Track.js';

export const searchController = {
  async search(req, res, next) {
    try {
      const query = (req.query.q || '').trim();

      if (!query) {
        return res.json({
          success: true,
          data: { tracks: [], artists: [], albums: [] },
        });
      }

      const regex = new RegExp(query.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'), 'i');

      const tracks = await Track.find({
        $or: [
          { title: regex },
          { artist: regex },
          { album: regex },
        ],
      })
        .select('-__v')
        .sort({ createdAt: -1 })
        .limit(50)
        .lean();

      const artistMap = new Map();
      tracks.forEach(t => {
        if (!artistMap.has(t.artist)) {
          artistMap.set(t.artist, {
            _id: new mongoose.Types.ObjectId(),
            name: t.artist,
            imageUrl: t.coverUrl || '',
            trackCount: 0,
          });
        }
        const entry = artistMap.get(t.artist);
        entry.trackCount++;
        if (t.coverUrl && !entry.imageUrl) {
          entry.imageUrl = t.coverUrl;
        }
      });
      const artists = [...artistMap.values()];

      const albumMap = new Map();
      tracks.forEach(t => {
        if (!albumMap.has(t.album)) {
          albumMap.set(t.album, {
            _id: new mongoose.Types.ObjectId(),
            title: t.album,
            artist: t.artist,
            coverUrl: t.coverUrl || '',
            trackCount: 0,
          });
        }
        const entry = albumMap.get(t.album);
        entry.trackCount++;
        if (t.coverUrl && !entry.coverUrl) {
          entry.coverUrl = t.coverUrl;
        }
      });
      const albums = [...albumMap.values()];

      const data = { tracks, artists, albums };

      return res.json({ success: true, data });
    } catch (error) {
      return next(error);
    }
  },
};