import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:shared_preferences/shared_preferences.dart';

class M3uSourcesState {
  final List<String> sources;
  final String? defaultUrl;

  M3uSourcesState({required this.sources, this.defaultUrl});

  M3uSourcesState copyWith({List<String>? sources, String? defaultUrl}) =>
      M3uSourcesState(
        sources: sources ?? this.sources,
        defaultUrl: defaultUrl ?? this.defaultUrl,
      );
}

class M3uSourcesNotifier extends StateNotifier<M3uSourcesState> {
  static const _kSourcesKey = 'm3u_sources';
  static const _kDefaultKey = 'm3u_default';

  M3uSourcesNotifier() : super(M3uSourcesState(sources: [], defaultUrl: null));

  Future<void> load() async {
    final sp = await SharedPreferences.getInstance();
    final list = sp.getStringList(_kSourcesKey) ?? <String>[];
    final def = sp.getString(_kDefaultKey);
    state = state.copyWith(sources: list, defaultUrl: def);
  }

  Future<void> add(String url) async {
    final u = url.trim();
    if (u.isEmpty) return;
    if (state.sources.contains(u)) return;
    final updated = [...state.sources, u];
    state = state.copyWith(sources: updated);
    final sp = await SharedPreferences.getInstance();
    await sp.setStringList(_kSourcesKey, updated);
  }

  Future<void> remove(String url) async {
    final updated = state.sources.where((s) => s != url).toList();
    String? def = state.defaultUrl;
    if (def == url) def = null;
    state = state.copyWith(sources: updated, defaultUrl: def);
    final sp = await SharedPreferences.getInstance();
    await sp.setStringList(_kSourcesKey, updated);
    if (def == null)
      await sp.remove(_kDefaultKey);
    else
      await sp.setString(_kDefaultKey, def);
  }

  Future<void> setDefault(String? url) async {
    state = state.copyWith(defaultUrl: url);
    final sp = await SharedPreferences.getInstance();
    if (url == null)
      await sp.remove(_kDefaultKey);
    else
      await sp.setString(_kDefaultKey, url);
  }
}

final m3uSourcesProvider =
    StateNotifierProvider<M3uSourcesNotifier, M3uSourcesState>((ref) {
  return M3uSourcesNotifier();
});