import 'dart:math';
import 'dart:typed_data';

import 'package:supabase_flutter/supabase_flutter.dart';

import '../../domain/models/track_model.dart';

class MusicService {
  const MusicService(this._client);

  final SupabaseClient _client;

  User get _currentUser {
    final user = _client.auth.currentUser;
    if (user == null) {
      throw StateError('No authenticated user');
    }
    return user;
  }

  /// Uploads a new track with an MP3 file and metadata.
  Future<void> uploadTrack({
    required Uint8List bytes,
    required String title,
    required String genreTag,
    required String extension,
  }) async {
    final user = _currentUser;
    final ts = DateTime.now().millisecondsSinceEpoch;
    final random = Random().nextInt(99999);
    final fileName = '$ts-$random.$extension';
    final path = 'tracks/${user.id}/$fileName';

    // Upload audio to Supabase Storage
    await _client.storage.from('tracks').uploadBinary(
          path,
          bytes,
          fileOptions: const FileOptions(upsert: false),
        );

    final audioUrl = _client.storage.from('tracks').getPublicUrl(path);

    // Insert track record into PostgreSQL
    await _client.from('tracks').insert({
      'user_id': user.id,
      'title': title.trim().isEmpty ? 'UNTITLED' : title.trim().toUpperCase(),
      'audio_url': audioUrl,
      'genre_tag': genreTag.trim().isEmpty ? 'UNKNOWN' : genreTag.trim().toUpperCase(),
      'plays': 0,
    });
  }

  /// Lists all tracks in chronological order.
  Future<List<TrackModel>> fetchTracks() async {
    final response = await _client
        .from('tracks')
        .select('*, profiles(username)')
        .order('created_at', ascending: false);

    return List<Map<String, dynamic>>.from(response).map((row) {
      final username = (row['profiles'] as Map<String, dynamic>?)?['username'] as String?;
      return TrackModel.fromJson(row, username: username);
    }).toList();
  }

  /// Increments the play count of a track.
  Future<void> incrementPlays(String trackId) async {
    await _client.rpc('increment_track_plays', params: {'track_id': trackId});
  }

  /// Fetches tracks for a specific user.
  Future<List<TrackModel>> fetchUserTracks(String userId) async {
    final response = await _client
        .from('tracks')
        .select('*, profiles(username)')
        .eq('user_id', userId)
        .order('created_at', ascending: false);

    return List<Map<String, dynamic>>.from(response).map((row) {
      final username = (row['profiles'] as Map<String, dynamic>?)?['username'] as String?;
      return TrackModel.fromJson(row, username: username);
    }).toList();
  }
}