pangolin/client/lib/widgets/content_top_bar.dart

// content_top_bar.dart — desktop/tablet 内容区顶栏（标题 + 在线状态 + 主题切换）
//
// 对照 ui_kits/desktop/dapp.jsx：height 52、下边框；左标题(display 17)，
// 右「● 已连接 CODE / ○ 未连接」(mono 12) + moon/sun 主题切换。
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../pangolin_theme.dart';
import '../state/app_providers.dart';
import '../state/connection_provider.dart';
import '../state/nodes_provider.dart';
import '../state/notices_provider.dart';
import 'notification_bell.dart';
import 'pangolin_icons.dart';

class ContentTopBar extends ConsumerWidget {
  const ContentTopBar({
    super.key,
    required this.title,
    this.onBack,
    this.showThemeToggle = true,
    this.titleSize = 17,
    this.onBell,
  });

  final String title;
  final VoidCallback? onBack;
  final bool showThemeToggle;
  final double titleSize;
  final VoidCallback? onBell;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final c = context.pangolin;
    final conn = ref.watch(connectionProvider);
    final node = ref.watch(effectiveNodeProvider);
    final mode = ref.watch(themeModeProvider);
    final isDark = mode == ThemeMode.dark;

    return Container(
      height: 52,
      padding: const EdgeInsets.symmetric(horizontal: 24),
      decoration: BoxDecoration(border: Border(bottom: BorderSide(color: c.border))),
      child: Row(children: [
        if (onBack != null) ...[
          IconButton(
            onPressed: onBack,
            icon: Icon(PangolinIcons.arrowLeft, size: 20, color: c.fg1),
            padding: EdgeInsets.zero,
            constraints: const BoxConstraints(minWidth: 32, minHeight: 32),
          ),
          const SizedBox(width: 4),
        ],
        Text(title,
            style: PangolinText.h3.copyWith(color: c.fg1, fontWeight: FontWeight.w700, fontSize: titleSize)),
        const Spacer(),
        Text(
          conn.phase == VpnPhase.on ? '● ${node.code}' : '○',
          style: PangolinText.mono.copyWith(
            fontSize: 12,
            fontWeight: FontWeight.w600,
            color: conn.phase == VpnPhase.on ? c.success : c.fg3,
          ),
        ),
        if (onBell != null) ...[
          const SizedBox(width: 12),
          NotificationBell(
            onTap: onBell!,
            hasUnread: (ref.watch(noticesProvider).valueOrNull?.unreadCount ?? 0) > 0,
          ),
        ],
        if (showThemeToggle) ...[
          const SizedBox(width: 12),
          InkWell(
            onTap: () => ref.read(themeModeProvider.notifier).state =
                isDark ? ThemeMode.light : ThemeMode.dark,
            borderRadius: BorderRadius.circular(PangolinRadius.sm),
            child: Padding(
              padding: const EdgeInsets.all(6),
              child: Icon(isDark ? PangolinIcons.sun : PangolinIcons.moon, size: 18, color: c.fg2),
            ),
          ),
        ],
      ]),
    );
  }
}