import 'package:flutter_riverpod/flutter_riverpod.dart';

import 'api.dart';
import 'format.dart';
import 'models.dart';

final apiProvider = Provider<Api>((ref) => throw UnimplementedError());

final startDateProvider = Provider<DateTime>(
  (ref) => throw UnimplementedError(),
);

class DataVersion extends Notifier<int> {
  @override
  int build() => 0;
  void bump() => state++;
}

final dataVersionProvider = NotifierProvider<DataVersion, int>(DataVersion.new);

class SessionNotifier extends Notifier<AppUser?> {
  SessionNotifier(this.initial);
  final AppUser? initial;

  @override
  AppUser? build() {
    final sub = ref.read(apiProvider).sessionEnded.listen((_) => _end());
    ref.onDispose(sub.cancel);
    return initial;
  }

  Future<void> login(String username, String password) async {
    final api = ref.read(apiProvider);
    final u = await api.login(username, password);
    state = u;
    try {
      ref.read(selectedDateProvider.notifier).set(await api.latestDrawDate());
    } on ApiException {// ignore: empty_catches
    }
  }

  Future<void> logout() async {
    ref.read(apiProvider).logout();
    _end();
  }

  void _end() {
    state = null;
    ref.invalidate(selectedDateProvider);
  }
}

final sessionProvider = NotifierProvider<SessionNotifier, AppUser?>(
  () => SessionNotifier(null),
);

class SelectedDate extends Notifier<DateTime> {
  @override
  DateTime build() => ref.read(startDateProvider);
  void set(DateTime d) => state = dateOnly(d);
}

final selectedDateProvider = NotifierProvider<SelectedDate, DateTime>(
  SelectedDate.new,
);

final resultsProvider = FutureProvider.family<DrawResults, DateTime>((ref, d) {
  ref.watch(dataVersionProvider);
  return ref.read(apiProvider).results(d);
});

final shopsProvider = FutureProvider.family<List<ShopDay>, DateTime>((ref, d) {
  ref.watch(dataVersionProvider);
  return ref.read(apiProvider).shops(d);
});

final shopDetailProvider = FutureProvider.family<ShopDetail, (int, DateTime)>((
  ref,
  k,
) {
  ref.watch(dataVersionProvider);
  return ref.read(apiProvider).shopDetail(k.$1, k.$2);
});

final ordersProvider = FutureProvider.family<List<Order>, DateTime>((ref, d) {
  ref.watch(dataVersionProvider);
  return ref.read(apiProvider).orders(d);
});

final orderProvider = FutureProvider.family<Order, int>((ref, id) {
  ref.watch(dataVersionProvider);
  return ref.read(apiProvider).order(id);
});

final monthProvider = FutureProvider.family<List<DrawInfo>, (int, int)>((
  ref,
  k,
) {
  ref.watch(dataVersionProvider);
  return ref.read(apiProvider).month(k.$1, k.$2);
});

final activeShopsProvider = FutureProvider<List<Shop>>((ref) {
  ref.watch(dataVersionProvider);
  return ref.read(apiProvider).activeShops();
});

final usersProvider = FutureProvider<List<AppUser>>((ref) {
  ref.watch(dataVersionProvider);
  return ref.read(apiProvider).users();
});

final userProvider = FutureProvider.family<AppUser, int>((ref, id) {
  ref.watch(dataVersionProvider);
  return ref.read(apiProvider).user(id);
});

Future<T> mutate<T>(WidgetRef ref, Future<T> Function() fn) async {
  final r = await fn();
  ref.read(dataVersionProvider.notifier).bump();
  return r;
}