// ignore_for_file: deprecated_member_use, duplicate_ignore

import 'package:flutter/material.dart';
import '../../core/service_locator.dart';
import '../home/home_screen.dart';
import '../recipes/recipes_screen.dart';
import '../favourites/favourites_screen.dart';
import '../bookmarks/bookmarks_screen.dart';
import '../community/community_screen.dart';
import '../session/session_screen.dart';
import 'app_router.dart';

/// Main navigation scaffold with bottom navigation bar and centered Add button.
class MainNavigationScaffold extends StatefulWidget {
  const MainNavigationScaffold({super.key});

  @override
  State<MainNavigationScaffold> createState() => MainNavigationScaffoldState();
}

class MainNavigationScaffoldState extends State<MainNavigationScaffold> {
  int _currentIndex = 0;
  bool _wasLoggedIn = false;

  bool get _isLoggedIn => ServiceLocator.instance.sessionService?.isLoggedIn ?? false;
  
  @override
  void initState() {
    super.initState();
    _wasLoggedIn = _isLoggedIn;
  }
  
  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    // Check if login state changed and rebuild if needed
    _checkLoginState();
  }
  
  void _checkLoginState() {
    final isLoggedIn = _isLoggedIn;
    if (isLoggedIn != _wasLoggedIn) {
      _wasLoggedIn = isLoggedIn;
      // Rebuild after a short delay to ensure state is fully updated
      Future.delayed(const Duration(milliseconds: 100), () {
        if (mounted) {
          setState(() {
            // Trigger rebuild to update navigation bar
          });
        }
      });
    }
  }
  
  void _onSessionChanged() {
    // Called when login/logout happens - rebuild immediately
    if (mounted) {
      setState(() {
        _wasLoggedIn = _isLoggedIn;
      });
      // Also check after a short delay to catch any async state changes
      Future.delayed(const Duration(milliseconds: 200), () {
        if (mounted) {
          setState(() {
            _wasLoggedIn = _isLoggedIn;
          });
        }
      });
    }
  }

  void _onItemTapped(int index) {
    final isLoggedIn = _isLoggedIn;
    
    // Only allow navigation to Recipes (1) and Bookmarks (2) if logged in
    // Community (4) and User (3) are always accessible
    if (!isLoggedIn && (index == 1 || index == 2)) {
      // Redirect to User/Session tab to prompt login
      setState(() {
        _currentIndex = 3; // User/Session tab
      });
      return;
    }
    
    setState(() {
      _currentIndex = index;
    });
  }

  /// Public method to navigate to User screen from AppBar.
  void navigateToUser() {
    setState(() {
      _currentIndex = 3; // User/Session tab
    });
  }

  /// Public method to navigate to Favourites screen (used from Recipes AppBar).
  void navigateToFavourites() {
    final isLoggedIn = _isLoggedIn;
    if (!isLoggedIn) {
      // Redirect to User/Session tab to prompt login
      navigateToUser();
      return;
    }
    // Navigate to Favourites as a full-screen route
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => const FavouritesScreen(),
      ),
    );
  }

  void _onAddRecipePressed(BuildContext context) async {
    final isLoggedIn = _isLoggedIn;
    
    // Only allow adding recipes if logged in
    if (!isLoggedIn) {
      // Redirect to User/Session tab to prompt login
      setState(() {
        _currentIndex = 3; // User/Session tab
      });
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text('Please log in to add recipes'),
          duration: Duration(seconds: 1),
        ),
      );
      return;
    }
    
    // Navigate to Add Recipe screen and reload recipes when returning
    final result = await Navigator.pushNamed(context, AppRoutes.addRecipe);
    // If recipe was saved, result will be true
    // Switch to Recipes tab to show the new recipe
    if (result == true) {
      setState(() {
        _currentIndex = 1; // Switch to Recipes tab
    });
    }
  }

  Widget _buildScreen(int index) {
    switch (index) {
      case 0:
        return const HomeScreen();
      case 1:
        // Recipes - only show if logged in, otherwise show login prompt
        // Use a key based on login state to force rebuild when login changes
        return RecipesScreen(
          key: _isLoggedIn 
            ? const ValueKey('recipes_logged_in')
            : const ValueKey('recipes_logged_out'),
        );
      case 2:
        // Bookmarks - only show if logged in
        // Use a key based on login state to force rebuild when login changes
        return BookmarksScreen(key: ValueKey(_isLoggedIn));
      case 3:
        return SessionScreen(onSessionChanged: _onSessionChanged);
      case 4:
        // Community - always accessible
        return const CommunityScreen();
      default:
        return const SizedBox();
    }
  }

  @override
  Widget build(BuildContext context) {
    // Rebuild when login state changes by checking it in build
    final isLoggedIn = _isLoggedIn;
    
    // Check login state in build to trigger rebuilds
    _checkLoginState();
    
    // Ensure current index is valid (if logged out, don't allow Recipes/Bookmarks)
    // Community (4) and User (3) are always accessible
    if (!isLoggedIn && (_currentIndex == 1 || _currentIndex == 2)) {
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (mounted) {
          setState(() {
            _currentIndex = 0; // Switch to Home if trying to access protected tabs
          });
        }
      });
    }
    
    return Scaffold(
      body: IndexedStack(
        index: _currentIndex,
        children: List.generate(5, (index) => _buildScreen(index)),
      ),
      bottomNavigationBar: _buildCustomBottomNav(context),
    );
  }

  Widget _buildCustomBottomNav(BuildContext context) {
    final isLoggedIn = _isLoggedIn;
    
    return Container(
      decoration: BoxDecoration(
        color: Theme.of(context).bottomNavigationBarTheme.backgroundColor ??
            Theme.of(context).scaffoldBackgroundColor,
        boxShadow: [
          BoxShadow(
            color: Colors.black.withOpacity(0.1),
            blurRadius: 4,
            offset: const Offset(0, -2),
          ),
        ],
      ),
      child: SafeArea(
        child: Container(
          height: kBottomNavigationBarHeight,
          padding: const EdgeInsets.symmetric(horizontal: 8),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: [
              // Left side items
              Expanded(
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: [
                    // Home
                    _buildNavItem(
                      icon: Icons.home,
                      label: 'Home',
                      index: 0,
                      onTap: () => _onItemTapped(0),
                    ),
                    // Recipes - only show if logged in
                    if (isLoggedIn)
                      _buildNavItem(
                        icon: Icons.menu_book,
                        label: 'Recipes',
                        index: 1,
                        onTap: () => _onItemTapped(1),
          ),
                  ],
                ),
              ),
              // Center Add Recipe button - only show if logged in
              if (isLoggedIn)
                Container(
                  width: 56,
                  height: 56,
                  margin: const EdgeInsets.only(bottom: 8),
                  child: Material(
                    color: Theme.of(context).primaryColor,
                    shape: const CircleBorder(),
                    child: InkWell(
                      onTap: () => _onAddRecipePressed(context),
                      customBorder: const CircleBorder(),
                      child: const Icon(
                        Icons.add,
                        color: Colors.white,
                        size: 28,
                      ),
                    ),
                  ),
                ),
              // Right side items
              Expanded(
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: [
                    // Bookmarks - only show if logged in
                    if (isLoggedIn)
                      _buildNavItem(
                        icon: Icons.bookmark,
                        label: 'Bookmarks',
                        index: 2,
                        onTap: () => _onItemTapped(2),
                      ),
                    // Community - always accessible
                    _buildNavItem(
                      icon: Icons.people,
                      label: 'Community',
                      index: 4,
                      onTap: () => _onItemTapped(4),
                    ),
                  ],
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildNavItem({
    required IconData icon,
    required String label,
    required int index,
    required VoidCallback onTap,
  }) {
    final isSelected = _currentIndex == index;
    return Expanded(
      child: Material(
        color: Colors.transparent,
        child: InkWell(
          onTap: onTap,
          child: Column(
            mainAxisSize: MainAxisSize.min,
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Icon(
                icon,
                color: isSelected
                    ? (Theme.of(context).brightness == Brightness.dark
                        ? Colors.blue.shade300 // Lighter blue for dark mode
                        : Theme.of(context).primaryColor)
                    : Theme.of(context).iconTheme.color?.withOpacity(0.6),
                size: 24,
              ),
              const SizedBox(height: 4),
              Text(
                label,
                style: TextStyle(
                  fontSize: 12,
                  color: isSelected
                      ? (Theme.of(context).brightness == Brightness.dark
                          ? Colors.blue.shade300 // Lighter blue for dark mode
                          : Theme.of(context).primaryColor)
                      // ignore: deprecated_member_use
                      : Theme.of(context)
                          .textTheme
                          .bodySmall
                          ?.color
                          ?.withOpacity(0.6),
                  fontWeight: isSelected ? FontWeight.w600 : FontWeight.normal,
                ),
          ),
        ],
          ),
        ),
      ),
    );
  }
}