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

const _kThemeMode = 'app_theme_mode';
const _kNotificationsEnabled = 'app_notifications_enabled';

String _themeToStr(ThemeMode m) {
  return switch (m) {
    ThemeMode.light => 'light',
    _ => 'system',
  };
}

ThemeMode _themeFromStr(String? s) {
  return switch (s) {
    'light' => ThemeMode.light,
    // Legacy: app no longer offers dark; map old saves to light.
    'dark' => ThemeMode.light,
    _ => ThemeMode.system,
  };
}

final themeModeProvider = NotifierProvider<ThemeModeNotifier, ThemeMode>(ThemeModeNotifier.new);

class ThemeModeNotifier extends Notifier<ThemeMode> {
  @override
  ThemeMode build() {
    Future.microtask(_load);
    return ThemeMode.system;
  }

  Future<void> _load() async {
    final p = await SharedPreferences.getInstance();
    final s = p.getString(_kThemeMode);
    if (s != null) {
      state = _themeFromStr(s);
    }
  }

  Future<void> setThemeMode(ThemeMode mode) async {
    state = mode;
    final p = await SharedPreferences.getInstance();
    await p.setString(_kThemeMode, _themeToStr(mode));
  }
}

final notificationsEnabledProvider =
    NotifierProvider<NotificationsEnabledNotifier, bool>(NotificationsEnabledNotifier.new);

class NotificationsEnabledNotifier extends Notifier<bool> {
  @override
  bool build() {
    Future.microtask(_load);
    return true;
  }

  Future<void> _load() async {
    final p = await SharedPreferences.getInstance();
    if (p.containsKey(_kNotificationsEnabled)) {
      state = p.getBool(_kNotificationsEnabled) ?? true;
    }
  }

  Future<void> setEnabled(bool value) async {
    state = value;
    final p = await SharedPreferences.getInstance();
    await p.setBool(_kNotificationsEnabled, value);
  }
}

/// Reads persisted value (default true if never set). Use before first notifier tick if needed.
Future<bool> readNotificationsEnabledFromPrefs() async {
  final p = await SharedPreferences.getInstance();
  if (!p.containsKey(_kNotificationsEnabled)) return true;
  return p.getBool(_kNotificationsEnabled) ?? true;
}