nj/app/lib/widgets/responsive_scaffold.dart

// 暖记响应式骨架 — 三级自适应布局
// 手机: 底部 TabBar | 平板: 侧边导航 | 桌面: 三栏

import 'package:flutter/material.dart';
import '../core/constants/breakpoints.dart';

/// 暖记自适应 Scaffold
class ResponsiveScaffold extends StatefulWidget {
  const ResponsiveScaffold({
    super.key,
    required this.selectedIndex,
    required this.onDestinationSelected,
    required this.body,
    this.floatingActionButton,
    this.appBarTitle,
    this.secondaryBody,
  });

  final int selectedIndex;
  final ValueChanged<int> onDestinationSelected;
  final Widget body;
  final Widget? floatingActionButton;
  final String? appBarTitle;
  final Widget? secondaryBody;

  @override
  State<ResponsiveScaffold> createState() => _ResponsiveScaffoldState();
}

class _ResponsiveScaffoldState extends State<ResponsiveScaffold> {
  @override
  Widget build(BuildContext context) {
    final width = MediaQuery.sizeOf(context).width;
    final deviceType = Breakpoints.getDeviceType(width);

    switch (deviceType) {
      case DeviceType.mobile:
        return _MobileLayout(
          selectedIndex: widget.selectedIndex,
          onDestinationSelected: widget.onDestinationSelected,
          body: widget.body,
          floatingActionButton: widget.floatingActionButton,
          appBarTitle: widget.appBarTitle,
        );
      case DeviceType.tablet:
        return _TabletLayout(
          selectedIndex: widget.selectedIndex,
          onDestinationSelected: widget.onDestinationSelected,
          body: widget.body,
          appBarTitle: widget.appBarTitle,
        );
      case DeviceType.desktop:
        return _DesktopLayout(
          selectedIndex: widget.selectedIndex,
          onDestinationSelected: widget.onDestinationSelected,
          body: widget.body,
          secondaryBody: widget.secondaryBody,
          appBarTitle: widget.appBarTitle,
        );
    }
  }
}

// ===== 导航项定义 =====

final _navItems = [
  NavigationDestination(
    icon: const Icon(Icons.home_outlined),
    selectedIcon: const Icon(Icons.home),
    label: '首页',
  ),
  NavigationDestination(
    icon: const Icon(Icons.calendar_month_outlined),
    selectedIcon: const Icon(Icons.calendar_month),
    label: '日历',
  ),
  NavigationDestination(
    icon: const Icon(Icons.auto_awesome_outlined),
    selectedIcon: const Icon(Icons.auto_awesome),
    label: '心情',
  ),
  NavigationDestination(
    icon: const Icon(Icons.search_outlined),
    selectedIcon: const Icon(Icons.search),
    label: '搜索',
  ),
  NavigationDestination(
    icon: const Icon(Icons.person_outline),
    selectedIcon: const Icon(Icons.person),
    label: '我的',
  ),
];

const _railItems = [
  NavigationRailDestination(
    icon: Icon(Icons.home_outlined),
    selectedIcon: Icon(Icons.home),
    label: Text('首页'),
  ),
  NavigationRailDestination(
    icon: Icon(Icons.calendar_month_outlined),
    selectedIcon: Icon(Icons.calendar_month),
    label: Text('日历'),
  ),
  NavigationRailDestination(
    icon: Icon(Icons.auto_awesome_outlined),
    selectedIcon: Icon(Icons.auto_awesome),
    label: Text('心情'),
  ),
  NavigationRailDestination(
    icon: Icon(Icons.search_outlined),
    selectedIcon: Icon(Icons.search),
    label: Text('搜索'),
  ),
  NavigationRailDestination(
    icon: Icon(Icons.person_outline),
    selectedIcon: Icon(Icons.person),
    label: Text('我的'),
  ),
];

// ===== 手机布局 — 底部 TabBar =====

class _MobileLayout extends StatelessWidget {
  const _MobileLayout({
    required this.selectedIndex,
    required this.onDestinationSelected,
    required this.body,
    this.floatingActionButton,
    this.appBarTitle,
  });

  final int selectedIndex;
  final ValueChanged<int> onDestinationSelected;
  final Widget body;
  final Widget? floatingActionButton;
  final String? appBarTitle;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: appBarTitle != null
          ? AppBar(title: Text(appBarTitle!))
          : null,
      body: body,
      floatingActionButton: floatingActionButton,
      bottomNavigationBar: NavigationBar(
        selectedIndex: selectedIndex,
        onDestinationSelected: onDestinationSelected,
        destinations: _navItems,
      ),
    );
  }
}

// ===== 平板布局 — 侧边 NavigationRail =====

class _TabletLayout extends StatelessWidget {
  const _TabletLayout({
    required this.selectedIndex,
    required this.onDestinationSelected,
    required this.body,
    this.appBarTitle,
  });

  final int selectedIndex;
  final ValueChanged<int> onDestinationSelected;
  final Widget body;
  final String? appBarTitle;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: appBarTitle != null
          ? AppBar(title: Text(appBarTitle!))
          : null,
      body: Row(
        children: [
          NavigationRail(
            selectedIndex: selectedIndex,
            onDestinationSelected: onDestinationSelected,
            destinations: _railItems,
            leading: Padding(
              padding: const EdgeInsets.symmetric(vertical: 16),
              child: Icon(
                Icons.edit_note_rounded,
                size: 32,
                color: Theme.of(context).colorScheme.primary,
              ),
            ),
          ),
          const VerticalDivider(thickness: 1, width: 1),
          Expanded(child: body),
        ],
      ),
    );
  }
}

// ===== 桌面布局 — 三栏 =====

class _DesktopLayout extends StatelessWidget {
  const _DesktopLayout({
    required this.selectedIndex,
    required this.onDestinationSelected,
    required this.body,
    this.secondaryBody,
    this.appBarTitle,
  });

  final int selectedIndex;
  final ValueChanged<int> onDestinationSelected;
  final Widget body;
  final Widget? secondaryBody;
  final String? appBarTitle;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: appBarTitle != null
          ? AppBar(title: Text(appBarTitle!))
          : null,
      body: Row(
        children: [
          NavigationRail(
            selectedIndex: selectedIndex,
            onDestinationSelected: onDestinationSelected,
            destinations: _railItems,
            extended: true,
            leading: Padding(
              padding: const EdgeInsets.symmetric(vertical: 16),
              child: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  Icon(
                    Icons.edit_note_rounded,
                    size: 32,
                    color: Theme.of(context).colorScheme.primary,
                  ),
                  const SizedBox(width: 12),
                  Text(
                    '暖记',
                    style: Theme.of(context).textTheme.headlineSmall?.copyWith(
                      fontFamily: 'Caveat',
                      color: Theme.of(context).colorScheme.primary,
                    ),
                  ),
                ],
              ),
            ),
          ),
          const VerticalDivider(thickness: 1, width: 1),
          // 主内容区
          Expanded(
            flex: 3,
            child: body,
          ),
          // 第二面板（日记详情/预览）
          if (secondaryBody != null) ...[
            const VerticalDivider(thickness: 1, width: 1),
            Expanded(
              flex: 2,
              child: secondaryBody!,
            ),
          ],
        ],
      ),
    );
  }
}