import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../core/theme/app_colors.dart';
import 'package:go_router/go_router.dart';
import 'package:tdesign_flutter/tdesign_flutter.dart';
import '../../core/i18n/app_localizations.dart';
import '../../core/theme/app_colors_extension.dart';
import 'nav_bar_config.dart';

/// 应用级 Scaffold：NavBar + body + 可选 BottomTabBar
///
/// 替代原来的 AppShell。每个页面自行包裹，无需 ShellRoute。
class AppScaffold extends ConsumerWidget {
  final Widget body;
  final bool showTabBar;

  const AppScaffold({super.key, required this.body, this.showTabBar = false});

  bool _isRootTab(String location) {
    return location == '/' || location == '/messages' || location == '/profile';
  }

  NavBarConfig _rootConfig(String location, AppLocalizations l10n) {
    if (location.startsWith('/messages')) {
      return NavBarConfig(
        title: l10n.get('tabMessages'),
        showBack: true,
        leadingIcon: Icons.close,
      );
    }
    if (location == '/') {
      return NavBarConfig(
        title: l10n.get('appName'),
        showBack: true,
        leadingIcon: Icons.close,
      );
    }
    if (location.startsWith('/profile')) {
      return NavBarConfig(
        title: l10n.get('tabProfile'),
        showBack: true,
        leadingIcon: Icons.close,
      );
    }
    return NavBarConfig.home;
  }

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    final l10n = AppLocalizations.of(context);
    final location = GoRouterState.of(context).uri.toString();
    final config = _isRootTab(location)
        ? _rootConfig(location, l10n)
        : ref.watch(navBarConfigProvider);

    SystemChrome.setSystemUIOverlayStyle(
      SystemUiOverlayStyle(
        statusBarColor: colors.bgCard,
        statusBarIconBrightness: Brightness.dark,
        statusBarBrightness: Brightness.light,
      ),
    );

    return Scaffold(
      backgroundColor: colors.bgPage,
      body: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          _NavBarView(
            config: config,
            location: location,
            onBack: () {
              if (_isRootTab(location)) {
                SystemNavigator.pop();
              } else {
                GoRouter.of(context).pop();
              }
            },
          ),
          Expanded(child: body),
          if (showTabBar)
            Container(
              color: colors.bgCard,
              child: _AppTabBar(location: location),
            ),
        ],
      ),
    );
  }
}

class _NavBarView extends StatelessWidget {
  final NavBarConfig config;
  final String location;
  final VoidCallback onBack;

  const _NavBarView({
    required this.config,
    required this.location,
    required this.onBack,
  });

  @override
  Widget build(BuildContext context) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    List<TDNavBarItem>? leftItems;
    if (config.showBack) {
      final icon = config.leadingIcon ?? TDIcons.chevron_left;
      leftItems = [
        TDNavBarItem(
          icon: icon,
          iconSize: 22,
          iconColor: colors.textPrimary,
          action: config.onBack ?? onBack,
        ),
      ];
    }

    List<TDNavBarItem>? rightItems;
    if (config.showRight && config.rightWidget != null) {
      rightItems = [TDNavBarItem(iconWidget: config.rightWidget, iconSize: 22)];
    }

    return TDNavBar(
      title: config.title,
      titleColor: colors.textPrimary,
      titleFontWeight: FontWeight.w600,
      titleFont: Font(size: AppFontSizes.title.toInt(), lineHeight: 26),
      backgroundColor: colors.bgCard,
      height: 56,
      centerTitle: true,
      useDefaultBack: false,
      screenAdaptation: true,
      leftBarItems: leftItems,
      rightBarItems: rightItems,
    );
  }
}

class _AppTabBar extends StatelessWidget {
  final String location;

  const _AppTabBar({required this.location});

  static int tabIndex(String location) {
    if (location.startsWith('/messages')) return 0;
    if (location == '/' ||
        (!location.startsWith('/messages') &&
            !location.startsWith('/profile'))) {
      return 1;
    }
    return 2;
  }

  @override
  Widget build(BuildContext context) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    final l10n = AppLocalizations.of(context);
    return LayoutBuilder(
      builder: (ctx, constraints) {
        if (constraints.maxWidth <= 0) return const SizedBox.shrink();
        final bottomPadding = MediaQuery.of(ctx).padding.bottom;
        return Padding(
          padding: EdgeInsets.only(top: 0, bottom: 8 + bottomPadding),
          child: TDBottomTabBar(
            TDBottomTabBarBasicType.iconText,
            useSafeArea: false,
            componentType: TDBottomTabBarComponentType.label,
            outlineType: TDBottomTabBarOutlineType.filled,
            backgroundColor: colors.bgCard,
            dividerColor: Colors.transparent,
            selectedBgColor: colors.primaryLight,
            unselectedBgColor: Colors.transparent,
            currentIndex: tabIndex(location),
            navigationTabs: [
              TDBottomTabBarTabConfig(
                tabText: l10n.get('tabMessages'),
                selectedIcon: Icon(
                  Icons.notifications,
                  size: 22,
                  color: colors.primary,
                ),
                unselectedIcon: Icon(
                  Icons.notifications_outlined,
                  size: 22,
                  color: colors.textSecondary,
                ),
                selectTabTextStyle: TextStyle(
                  fontSize: 10,
                  fontWeight: FontWeight.w600,
                  color: colors.primary,
                ),
                unselectTabTextStyle: TextStyle(
                  fontSize: 10,
                  color: colors.textSecondary,
                ),
                onTap: () => context.go('/messages'),
              ),
              TDBottomTabBarTabConfig(
                tabText: l10n.get('tabWorkbench'),
                selectedIcon: Icon(
                  Icons.dashboard,
                  size: 22,
                  color: colors.primary,
                ),
                unselectedIcon: Icon(
                  Icons.dashboard_outlined,
                  size: 22,
                  color: colors.textSecondary,
                ),
                selectTabTextStyle: TextStyle(
                  fontSize: 10,
                  fontWeight: FontWeight.w600,
                  color: colors.primary,
                ),
                unselectTabTextStyle: TextStyle(
                  fontSize: 10,
                  color: colors.textSecondary,
                ),
                onTap: () => context.go('/'),
              ),
              TDBottomTabBarTabConfig(
                tabText: l10n.get('tabProfile'),
                selectedIcon: Icon(
                  Icons.person,
                  size: 22,
                  color: colors.primary,
                ),
                unselectedIcon: Icon(
                  Icons.person_outline,
                  size: 22,
                  color: colors.textSecondary,
                ),
                selectTabTextStyle: TextStyle(
                  fontSize: 10,
                  fontWeight: FontWeight.w600,
                  color: colors.primary,
                ),
                unselectTabTextStyle: TextStyle(
                  fontSize: 10,
                  color: colors.textSecondary,
                ),
                onTap: () => context.go('/profile'),
              ),
            ],
          ),
        );
      },
    );
  }
}