import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter/material.dart';
import 'package:hive_flutter/hive_flutter.dart';
import 'app_lifecycle_provider.dart'; // v2.0: Battery-efficient observer
import '../models/user_profile.dart';
import '../theme/app_theme.dart';

// v2.0: Theme Mode Enum
enum AppThemeMode {
  light,
  dark,
  system,
  autoTime, // Night Mode (20:00 - 06:00)
}

// Provider for the UserProfile box
// Provider for the UserProfile box
final userProfileBoxProvider = Provider<Box<UserProfile>>((ref) {
  // Directly access the open box (Splash Screen ensures this is open)
  return Hive.box<UserProfile>('user_profile');
});

// Central Notifier for User Profile (Font, Theme, Identity)
final userProfileProvider = NotifierProvider<UserProfileNotifier, UserProfile>(UserProfileNotifier.new);

class UserProfileNotifier extends Notifier<UserProfile> {
  late Box<UserProfile> _box;

  @override
  UserProfile build() {
    // Phase 1 Optimization: Access box directly as it's guaranteed to be open by SplashScreen
    _box = Hive.box<UserProfile>('user_profile');
    
    // Return existing profile or create default
    return _box.get('current_user') ?? 
           UserProfile(createdAt: DateTime.now());
  }

  Future<void> _save(UserProfile profile) async {
    state = profile; // Update UI immediately
    await _box.put('current_user', profile);
  }

  Future<void> setFontPreference(String preference) async {
    final newState = state.copyWith(
      fontPreference: preference,
      updatedAt: DateTime.now(),
    );
    await _save(newState);
  }

  Future<void> setThemeMode(String mode) async {
    final newState = state.copyWith(
      themeMode: mode,
      updatedAt: DateTime.now(),
    );
    await _save(newState);
  }

  Future<void> setIdentity({String? mbti, String? sakePersonaMbti, DateTime? birthdate, String? nickname, String? gender}) async {
    final newState = state.copyWith(
      mbti: mbti ?? state.mbti,
      sakePersonaMbti: sakePersonaMbti ?? state.sakePersonaMbti,
      birthdate: birthdate ?? state.birthdate,
      nickname: nickname ?? state.nickname,
      gender: gender ?? state.gender,
      updatedAt: DateTime.now(),
    );
    await _save(newState);
  }

  Future<void> setSakePersonaMbti(String? persona) async {
    final newState = state.copyWith(
      sakePersonaMbti: persona,
      updatedAt: DateTime.now(),
    );
    await _save(newState);
  }

  Future<void> toggleBusinessMode() async {
     final newState = state.copyWith(
       isBusinessMode: !state.isBusinessMode,
       updatedAt: DateTime.now(),
     );
     await _save(newState);
  }

  Future<void> setDefaultMarkup(double value) async {
     final newState = state.copyWith(
       defaultMarkup: value,
       updatedAt: DateTime.now(),
     );
     await _save(newState);
  }

  Future<void> completeOnboarding() async {
     final newState = state.copyWith(
       hasCompletedOnboarding: true,
       updatedAt: DateTime.now(),
     );
     await _save(newState);
  }

  Future<void> updateTotalExp(int newExp) async {
    final newState = state.copyWith(
      totalExp: newExp,
      updatedAt: DateTime.now(),
    );
    await _save(newState);
  }

  Future<void> updateUnlockedBadges(List<String> badges) async {
    final newState = state.copyWith(
      unlockedBadges: badges,
      updatedAt: DateTime.now(),
    );
    await _save(newState);
  }

  // REMOVED: completeTutorial() - Tutorial system removed in favor of guide screen

  Future<void> setLocale(String locale) async {
    final newState = state.copyWith(
      locale: locale,
      updatedAt: DateTime.now(),
    );
    await _save(newState);
  }

  Future<void> setColorVariant(String variant) async {
    final newState = state.copyWith(
      colorVariant: variant,
      updatedAt: DateTime.now(),
    );
    await _save(newState);
  }
}

// Helper Providers for easy access
final fontPreferenceProvider = Provider<String>((ref) {
  return ref.watch(userProfileProvider).fontPreference;
});

// v2.0: Enhanced Theme Logic
final themeModeProvider = Provider<ThemeMode>((ref) {
  final modeString = ref.watch(userProfileProvider).themeMode;
  
  // Mapping String -> Enum logic
  if (modeString == 'auto_time') {
    // Dependency on lifecycle to trigger updates when app resumes
    ref.watch(appLifecycleProvider);
    
    final hour = DateTime.now().hour;
    // 20:00 - 06:00 is Night
    final isNight = hour >= 20 || hour < 6;
    return isNight ? ThemeMode.dark : ThemeMode.light;
  }
  
  switch (modeString) {
    case 'light': return ThemeMode.light;
    case 'dark': return ThemeMode.dark;
    default: return ThemeMode.system;
  }
});

// Helper Providers
final colorVariantProvider = Provider<String>((ref) {
  return ref.watch(userProfileProvider).colorVariant;
});

// Helper function to map font string to enum
AppFontStyle _mapFontString(String fontString) {
  switch (fontString) {
    case 'sans':
      return AppFontStyle.sans;
    case 'serif':
      return AppFontStyle.serif;
    case 'pottaOne':
      return AppFontStyle.pottaOne;
    case 'digital':
      return AppFontStyle.digital;
    default:
      return AppFontStyle.sans; // Default to sans
  }
}

// Helper function to map color variant string to enum
ColorVariant _mapColorVariant(String variantString) {
  switch (variantString) {
    case 'washi_sumi_kohaku':
      return ColorVariant.washiSumiKohaku;
    case 'current':
      return ColorVariant.current;
    default:
      return ColorVariant.washiSumiKohaku; // Default to Theme A
  }
}

// Theme Data Providers
final lightThemeProvider = Provider<ThemeData>((ref) {
  final fontString = ref.watch(fontPreferenceProvider);
  final fontStyle = _mapFontString(fontString);
  final variantString = ref.watch(colorVariantProvider);
  final colorVariant = _mapColorVariant(variantString);
  return AppTheme.createTheme(fontStyle, Brightness.light, colorVariant);
});

final darkThemeProvider = Provider<ThemeData>((ref) {
  final fontString = ref.watch(fontPreferenceProvider);
  final fontStyle = _mapFontString(fontString);
  final variantString = ref.watch(colorVariantProvider);
  final colorVariant = _mapColorVariant(variantString);
  return AppTheme.createTheme(fontStyle, Brightness.dark, colorVariant);
});

// Locale Provider
final localeProvider = Provider<Locale>((ref) {
  final localeCode = ref.watch(userProfileProvider.select((p) => p.locale));
  // Support: 'ja', 'en', 'fr', 'de'
  return Locale(localeCode);
});