import 'package:flutter/material.dart';
import 'dashboard_screen.dart';
import 'chat_list_screen.dart';
import 'settings_screen.dart';

class MainNavigationScreen extends StatefulWidget {
  const MainNavigationScreen({super.key});

  @override
  State<MainNavigationScreen> createState() => _MainNavigationScreenState();
}

class _MainNavigationScreenState extends State<MainNavigationScreen> {
  int _currentIndex = 0;

  final List<Widget> _screens = [
    const DashboardScreen(),
    const ChatListScreen(),
    const PlaceholderScreen(),
    const SettingsScreen(),
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: IndexedStack(
        index: _currentIndex,
        children: _screens,
      ),
      bottomNavigationBar: NavigationBar(
        selectedIndex: _currentIndex,
        onDestinationSelected: (index) {
          setState(() {
            _currentIndex = index;
          });
        },
        destinations: const [
          NavigationDestination(
            icon: Icon(Icons.home_outlined),
            selectedIcon: Icon(Icons.home),
            label: 'Home',
          ),
          NavigationDestination(
            icon: Icon(Icons.chat_bubble_outline),
            selectedIcon: Icon(Icons.chat_bubble),
            label: 'AI Chat',
          ),
          NavigationDestination(
            icon: Icon(Icons.more_horiz),
            selectedIcon: Icon(Icons.more_horiz),
            label: 'More',
          ),
          NavigationDestination(
            icon: Icon(Icons.settings_outlined),
            selectedIcon: Icon(Icons.settings),
            label: 'Settings',
          ),
        ],
      ),
    );
  }
}

class PlaceholderScreen extends StatelessWidget {
  const PlaceholderScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;

    return Scaffold(
      appBar: AppBar(
        title: const Text('More'),
      ),
      body: Center(
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Icon(
                Icons.construction,
                size: 64,
                color: colorScheme.onSurfaceVariant,
              ),
              const SizedBox(height: 16),
              Text(
                'Coming Soon',
                style: Theme.of(context).textTheme.titleLarge,
              ),
              const SizedBox(height: 8),
              Text(
                'This section is under development.',
                style: TextStyle(color: colorScheme.onSurfaceVariant),
                textAlign: TextAlign.center,
              ),
            ],
          ),
        ),
      ),
    );
  }
}