pangolin/client/lib/shell/desktop_shell.dart

// desktop_shell.dart — 桌面外壳（左侧栏 + 顶栏 + 内容区）
//
// 对照 ui_kits/desktop/dapp.jsx：920×600 窗口、204 侧栏(6 项)、52 顶栏、内容区。
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../pangolin_theme.dart';
import '../screens/account_page.dart';
import '../screens/connect_page.dart';
import '../screens/contact_page.dart';
import '../screens/invite_page.dart';
import '../screens/nodes_page.dart';
import '../screens/orders_page.dart';
import '../screens/payment_page.dart';
import '../screens/purchase_page.dart';
import '../screens/settings_page.dart';
import '../screens/stats_page.dart';
import '../state/app_providers.dart';
import '../state/navigation_provider.dart';
import '../widgets/account_screens.dart';
import '../widgets/content_top_bar.dart';
import '../widgets/nav_sidebar.dart';
import '../widgets/pangolin_icons.dart';

class DesktopShell extends ConsumerWidget {
  const DesktopShell({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final c = context.pangolin;
    final t = ref.watch(appTextProvider);
    final view = ref.watch(navViewProvider);

    // 「我的」移到侧栏顶部品牌按钮(见 NavSidebar);联系放设置下面。
    final items = <NavSidebarItem>[
      (icon: PangolinIcons.power, label: t.tabConnect, view: NavView.connect),
      (icon: PangolinIcons.globe, label: t.tabServers, view: NavView.servers),
      (icon: PangolinIcons.chartNoAxesColumn, label: t.tabStats, view: NavView.stats),
      (icon: PangolinIcons.settings, label: t.settingsTitle, view: NavView.settings),
      (icon: PangolinIcons.messageCircle, label: t.contactTitle, view: NavView.contact),
    ];

    final titles = <NavView, String>{
      NavView.connect: t.tabConnect,
      NavView.servers: t.tabServers,
      NavView.stats: t.tabStats,
      NavView.account: t.tabMe,
      NavView.contact: t.contactTitle,
      NavView.settings: t.settingsTitle,
      NavView.plans: t.choosePlan,
      NavView.redeem: t.redeemTitle,
      NavView.devices: t.myDevices,
      NavView.purchase: t.purchaseTitle,
      NavView.payment: t.paymentTitle,
      NavView.orders: t.ordersTitle,
      NavView.invite: t.inviteTitle,
    };

    void go(NavView v) => ref.read(navViewProvider.notifier).state = v;

    Widget content() {
      switch (view) {
        case NavView.connect:
          return ConnectPage(isWide: true, onOpenNodes: () => go(NavView.servers));
        case NavView.servers:
          return NodesPage(isWide: true, onPicked: () => go(NavView.connect));
        case NavView.stats:
          return const StatsPage(isWide: true);
        case NavView.account:
          return const AccountPage(isWide: true);
        case NavView.contact:
          return const ContactPage();
        case NavView.settings:
          return const SettingsPage();
        // 账户下钻子页（内容区，顶栏带返回）
        case NavView.plans:
          // 只有 pro 走 pay v2 购买通道;team 等仍走既有兑换/联系人工流程。
          return PlansScreen(t: t, embedded: true, onChoose: (code) => go(code == 'pro' ? NavView.purchase : NavView.redeem));
        case NavView.redeem:
          return RedeemScreen(t: t, embedded: true);
        case NavView.devices:
          return DevicesScreen(t: t, embedded: true);
        case NavView.purchase:
          return PurchaseScreen(t: t, embedded: true, onOrderCreated: () => go(NavView.payment));
        case NavView.payment:
          return PaymentScreen(t: t, embedded: true, onDone: () => go(NavView.account));
        case NavView.orders:
          return OrdersScreen(t: t, embedded: true);
        case NavView.invite:
          return InviteScreen(t: t, embedded: true);
        case NavView.notifications:
          // TODO(task-6): 通知屏尚未接线,占位回落账户页,避免非穷尽 switch 编译失败。
          return const AccountPage(isWide: true);
      }
    }

    // 子页返回目标:payment → purchase(换方式/失败重试仍在购买语境内);
    // 其余下钻子页（含 purchase 本身）→ account。
    VoidCallback? backTarget() {
      if (view == NavView.payment) return () => go(NavView.purchase);
      if (kAccountSubViews.contains(view)) return () => go(NavView.account);
      return null;
    }

    return ColoredBox(
      color: c.bg,
      child: Row(children: [
        NavSidebar(items: items),
        Expanded(
          child: Column(children: [
            ContentTopBar(
              title: titles[view] ?? t.brand,
              onBack: backTarget(),
            ),
            Expanded(child: content()),
          ]),
        ),
      ]),
    );
  }
}