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
class AppScaffold extends ConsumerWidget {
  final Widget body;
  final bool showTabBar;
  final bool resizeToAvoidBottomInset;
  final NavBarConfig? navConfig;

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

  bool _isRootTab(String location) {
    final path = location.split('?').first;
    return path == '/' || path == '/messages' || path == '/profile';
  }

  String? _titleForRoute(String location, AppLocalizations l10n) {
    final path = location.split('?').first;
    if (path == '/') return l10n.get('appName');
    if (path == '/messages') return l10n.get('tabMessages');
    if (path == '/profile') return l10n.get('tabProfile');
    if (path.startsWith('/expense/list')) return l10n.get('expenseList');
    if (path.startsWith('/expense/import-apply')) return l10n.get('importExpenseApply');
    if (path.startsWith('/expense/detail')) return l10n.get('expenseDetail');
    if (path.startsWith('/expense/create') || path.startsWith('/expense/edit')) return l10n.get('expenseApply');
    if (path.startsWith('/expense-apply/list')) return l10n.get('expenseApplyList');
    if (path.startsWith('/expense-apply/detail')) return l10n.get('expenseApplyDetail');
    if (path.startsWith('/expense-apply/create')) return l10n.get('expenseApplyRequest');
    if (path.startsWith('/overtime/list')) return l10n.get('overtimeList');
    if (path.startsWith('/overtime/detail')) return l10n.get('overtimeDetail');
    if (path.startsWith('/overtime/create')) return l10n.get('overtimeRequest');
    if (path.startsWith('/vehicle/list')) return l10n.get('vehicleList');
    if (path.startsWith('/vehicle/detail')) return l10n.get('vehicleDetail');
    if (path.startsWith('/vehicle/create')) return l10n.get('vehicleRequest');
    if (path.startsWith('/outing-log/list')) return l10n.get('outingLogList');
    if (path.startsWith('/outing-log/detail')) return l10n.get('outingLogDetail');
    if (path.startsWith('/outing-log/create')) return l10n.get('outingLogCreate');
    if (path.startsWith('/announcement/list')) return l10n.get('announcementList');
    if (path.startsWith('/announcement/detail')) return l10n.get('announcementDetail');
    if (path.startsWith('/announcement/create')) return l10n.get('announcementCreate');
    if (path.startsWith('/report/expense-detail')) return l10n.get('reportExpenseDetail');
    if (path.startsWith('/report/expense-apply-detail')) return l10n.get('reportExpenseApplyDetail');
    if (path.startsWith('/report/overtime')) return l10n.get('reportOvertimeDetail');
    if (path.startsWith('/report/vehicle')) return l10n.get('reportVehicleDetail');
    if (path.startsWith('/report/outing-log')) return l10n.get('reportOutingLogDetail');
    if (path.startsWith('/admin/permissions')) return l10n.get('permissionManagement');
    return null;
  }

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

  NavBarConfig _resolve(NavBarConfig cfg, String location, AppLocalizations l10n) {
    final routeTitle = _titleForRoute(location, l10n);
    if (routeTitle == null) return cfg;
    return NavBarConfig(
      title: routeTitle,
      showBack: cfg.showBack,
      showRight: cfg.showRight,
      rightWidget: cfg.rightWidget,
      onBack: cfg.onBack,
      leadingIcon: cfg.leadingIcon,
    );
  }

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    SystemChrome.setSystemUIOverlayStyle(
      const SystemUiOverlayStyle(statusBarColor: Colors.transparent, statusBarIconBrightness: Brightness.dark),
    );
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    final l10n = AppLocalizations.of(context);
    final location = GoRouterState.of(context).uri.toString();
    final config = navConfig != null
        ? _resolve(navConfig!, location, l10n)
        : _rootConfig(location, l10n);
    // 页面可通过 pageBackProvider 覆盖返回按钮行为（如 create 页面的 _doPop）
    final pageBack = ref.watch(pageBackProvider);

    return Scaffold(
      resizeToAvoidBottomInset: resizeToAvoidBottomInset,
      backgroundColor: colors.bgPage,
      body: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          _NavBarView(
            config: config,
            location: location,
            pageBack: pageBack,
            onBack: () {
              if (_isRootTab(location)) {
                SystemNavigator.pop();
              } else {
                final router = GoRouter.of(context);
                if (router.canPop()) {
                  router.pop();
                } else {
                  SystemNavigator.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? pageBack;
  final VoidCallback onBack;
  const _NavBarView({required this.config, required this.location, this.pageBack, 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;
      // config.onBack（路由级声明）优先于 pageBack（页面级 Provider），
      // 防止 Provider 残留值泄漏到不相关的页面
      final backAction = config.onBack ?? pageBack ?? onBack;
      leftItems = [TDNavBarItem(icon: icon, iconSize: 22, iconColor: colors.textPrimary, action: backAction)];
    }
    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'),
            ),
          ],
        ),
      );
    });
  }
}