import 'package:flutter/material.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
import '../home/home_page.dart';
import '../market/market_page.dart';
import '../trade/trade_page.dart';
import '../asset/asset_page.dart';
import '../mine/mine_page.dart';

/// 主页面（使用 shadcn_ui 风格）
class MainPage extends StatefulWidget {
  const MainPage({super.key});

  @override
  State<MainPage> createState() => _MainPageState();
}

class _MainPageState extends State<MainPage> {
  int _currentIndex = 0;

  final List<Widget> _pages = [
    const HomePage(),
    const MarketPage(),
    const TradePage(),
    const AssetPage(),
    const MinePage(),
  ];

  final List<_TabItem> _tabs = [
    _TabItem('首页', LucideIcons.house, LucideIcons.house),
    _TabItem('行情', LucideIcons.trendingUp, LucideIcons.trendingUp),
    _TabItem('交易', LucideIcons.arrowLeftRight, LucideIcons.arrowLeftRight),
    _TabItem('资产', LucideIcons.wallet, LucideIcons.wallet),
    _TabItem('我的', LucideIcons.user, LucideIcons.user),
  ];

  @override
  Widget build(BuildContext context) {
    final theme = ShadTheme.of(context);

    return Scaffold(
      body: IndexedStack(
        index: _currentIndex,
        children: _pages,
      ),
      bottomNavigationBar: Container(
        decoration: BoxDecoration(
          color: theme.colorScheme.background,
          border: Border(
            top: BorderSide(color: theme.colorScheme.border),
          ),
        ),
        child: SafeArea(
          child: Padding(
            padding: const EdgeInsets.symmetric(vertical: 8),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceAround,
              children: _tabs.asMap().entries.map((entry) {
                final index = entry.key;
                final tab = entry.value;
                final isSelected = index == _currentIndex;

                return GestureDetector(
                  onTap: () => setState(() => _currentIndex = index),
                  behavior: HitTestBehavior.opaque,
                  child: Container(
                    padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
                    child: Column(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        Icon(
                          tab.icon,
                          color: isSelected
                              ? theme.colorScheme.primary
                              : theme.colorScheme.mutedForeground,
                          size: 24,
                        ),
                        const SizedBox(height: 4),
                        Text(
                          tab.label,
                          style: TextStyle(
                            fontSize: 12,
                            color: isSelected
                                ? theme.colorScheme.primary
                                : theme.colorScheme.mutedForeground,
                            fontWeight: isSelected ? FontWeight.w600 : FontWeight.normal,
                          ),
                        ),
                      ],
                    ),
                  ),
                );
              }).toList(),
            ),
          ),
        ),
      ),
    );
  }
}

class _TabItem {
  final String label;
  final IconData icon;
  final IconData selectedIcon;

  _TabItem(this.label, this.icon, this.selectedIcon);
}

/// IndexedStack 用于保持页面状态
class IndexedStack extends StatefulWidget {
  final int index;
  final List<Widget> children;

  const IndexedStack({
    super.key,
    required this.index,
    required this.children,
  });

  @override
  State<IndexedStack> createState() => _IndexedStackState();
}

class _IndexedStackState extends State<IndexedStack> {
  @override
  Widget build(BuildContext context) {
    return Stack(
      children: widget.children.asMap().entries.map((entry) {
        return Positioned.fill(
          child: Offstage(
            offstage: entry.key != widget.index,
            child: TickerMode(
              enabled: entry.key == widget.index,
              child: entry.value,
            ),
          ),
        );
      }).toList(),
    );
  }
}