import 'package:flutter/material.dart';
import '../app/theme/app_colors.dart';
import '../app/i18n/app_localizations.dart';
import '../features/coupons/presentation/pages/home_page.dart';
import '../features/coupons/presentation/pages/market_page.dart';
import '../features/message/presentation/pages/message_page.dart';
import '../features/profile/presentation/pages/profile_page.dart';

/// GenexMobile主Shell - Bottom Navigation
///
/// Tab: 首页 / 交易 / 消息 / 我的
class MainShell extends StatefulWidget {
  const MainShell({super.key});

  @override
  State<MainShell> createState() => _MainShellState();
}

class _MainShellState extends State<MainShell> {
  int _currentIndex = 0;

  final _pages = const [
    HomePage(),
    MarketPage(),
    MessagePage(),
    ProfilePage(),
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: IndexedStack(
        index: _currentIndex,
        children: _pages,
      ),
      bottomNavigationBar: Container(
        decoration: const BoxDecoration(
          color: AppColors.surface,
          border: Border(top: BorderSide(color: AppColors.borderLight, width: 0.5)),
        ),
        child: NavigationBar(
          selectedIndex: _currentIndex,
          onDestinationSelected: (index) => setState(() => _currentIndex = index),
          destinations: [
            _buildDestination(Icons.home_rounded, Icons.home_outlined, context.t('nav.home')),
            _buildDestination(Icons.show_chart_rounded, Icons.show_chart_outlined, context.t('nav.trading')),
            _buildBadgeDestination(
              Icons.notifications_rounded,
              Icons.notifications_outlined,
              context.t('nav.messages'),
              2,
            ),
            _buildDestination(Icons.person_rounded, Icons.person_outlined, context.t('nav.profile')),
          ],
        ),
      ),
    );
  }

  NavigationDestination _buildDestination(
    IconData selected,
    IconData unselected,
    String label,
  ) {
    return NavigationDestination(
      icon: Icon(unselected),
      selectedIcon: Icon(selected),
      label: label,
    );
  }

  NavigationDestination _buildBadgeDestination(
    IconData selected,
    IconData unselected,
    String label,
    int count,
  ) {
    return NavigationDestination(
      icon: Badge(
        label: Text('$count', style: const TextStyle(fontSize: 10)),
        child: Icon(unselected),
      ),
      selectedIcon: Badge(
        label: Text('$count', style: const TextStyle(fontSize: 10)),
        child: Icon(selected),
      ),
      label: label,
    );
  }
}