fix: workspaces empty error in local mode (#5045)

* fix: workspaces empty error in local mode

* fix: not allowed the user delete the only workspace

frontend/appflowy_flutter/lib/mobile/presentation/home/mobile_home_page_header.dart

@@ -107,8 +107,7 @@ class _MobileWorkspace extends StatelessWidget {
     return BlocBuilder<UserWorkspaceBloc, UserWorkspaceState>(
       builder: (context, state) {
         final currentWorkspace = state.currentWorkspace;
-        final workspaces = state.workspaces;
+        if (currentWorkspace == null) {
-        if (currentWorkspace == null || workspaces.isEmpty) {
           return const SizedBox.shrink();
         }
         return GestureDetector(

frontend/appflowy_flutter/lib/workspace/application/user/user_workspace_bloc.dart

@@ -8,6 +8,7 @@ import 'package:appflowy/user/application/user_service.dart';
 import 'package:appflowy_backend/log.dart';
 import 'package:appflowy_backend/protobuf/flowy-error/code.pbenum.dart';
 import 'package:appflowy_backend/protobuf/flowy-error/errors.pb.dart';
+import 'package:appflowy_backend/protobuf/flowy-folder/protobuf.dart';
 import 'package:appflowy_backend/protobuf/flowy-user/protobuf.dart';
 import 'package:appflowy_result/appflowy_result.dart';
 import 'package:collection/collection.dart';
@@ -36,10 +37,11 @@ class UserWorkspaceBloc extends Bloc<UserWorkspaceEvent, UserWorkspaceState> {
               ..start();
 
             final result = await _fetchWorkspaces();
+            final currentWorkspace = result.$1;
+            final workspaces = result.$2;
             final isCollabWorkspaceOn =
                 userProfile.authenticator != AuthenticatorPB.Local &&
                     FeatureFlag.collaborativeWorkspace.isOn;
-            final currentWorkspace = result.$1;
             if (currentWorkspace != null && result.$3 == true) {
               final result = await _userService
                   .openWorkspace(currentWorkspace.workspaceId);
@@ -53,7 +55,7 @@ class UserWorkspaceBloc extends Bloc<UserWorkspaceEvent, UserWorkspaceState> {
             emit(
               state.copyWith(
                 currentWorkspace: currentWorkspace,
-                workspaces: result.$2,
+                workspaces: workspaces,
                 isCollabWorkspaceOn: isCollabWorkspaceOn,
                 actionResult: null,
               ),
@@ -89,7 +91,10 @@ class UserWorkspaceBloc extends Bloc<UserWorkspaceEvent, UserWorkspaceState> {
             });
           },
           deleteWorkspace: (workspaceId) async {
-            if (state.workspaces.length <= 1) {
+            final remoteWorkspaces = await _fetchWorkspaces().then(
+              (value) => value.$2,
+            );
+            if (state.workspaces.length <= 1 || remoteWorkspaces.length <= 1) {
               // do not allow to delete the last workspace, otherwise the user
               // cannot do create workspace again
               final result = FlowyResult.failure(
@@ -280,6 +285,9 @@ class UserWorkspaceBloc extends Bloc<UserWorkspaceEvent, UserWorkspaceState> {
       final currentWorkspace =
           await _userService.getCurrentWorkspace().getOrThrow();
       final workspaces = await _userService.getWorkspaces().getOrThrow();
+      if (workspaces.isEmpty) {
+        workspaces.add(convertWorkspacePBToUserWorkspace(currentWorkspace));
+      }
       UserWorkspacePB? currentWorkspaceInList = workspaces
           .firstWhereOrNull((e) => e.workspaceId == currentWorkspace.id);
       if (lastOpenedWorkspaceId != null) {
@@ -289,7 +297,7 @@ class UserWorkspaceBloc extends Bloc<UserWorkspaceEvent, UserWorkspaceState> {
           currentWorkspaceInList = lastOpenedWorkspace;
         }
       }
-      currentWorkspaceInList ??= workspaces.first;
+      currentWorkspaceInList ??= workspaces.firstOrNull;
       return (
         currentWorkspaceInList,
         workspaces
@@ -303,6 +311,13 @@ class UserWorkspaceBloc extends Bloc<UserWorkspaceEvent, UserWorkspaceState> {
       return (null, <UserWorkspacePB>[], false);
     }
   }
+
+  UserWorkspacePB convertWorkspacePBToUserWorkspace(WorkspacePB workspace) {
+    return UserWorkspacePB.create()
+      ..workspaceId = workspace.id
+      ..name = workspace.name
+      ..createdAtTimestamp = workspace.createTime;
+  }
 }
 
 @freezed

frontend/appflowy_flutter/lib/workspace/presentation/home/menu/sidebar/sidebar.dart

@@ -219,7 +219,14 @@ class _SidebarState extends State<_Sidebar> {
           // user or workspace, setting
           Padding(
             padding: menuHorizontalInset,
-            child: context.read<UserWorkspaceBloc>().state.isCollabWorkspaceOn
+            child:
+                // if the workspaces are empty, show the user profile instead
+                context.read<UserWorkspaceBloc>().state.isCollabWorkspaceOn &&
+                        context
+                            .read<UserWorkspaceBloc>()
+                            .state
+                            .workspaces
+                            .isNotEmpty
                     ? SidebarWorkspace(
                         userProfile: widget.userProfile,
                       )

frontend/appflowy_flutter/lib/workspace/presentation/home/menu/sidebar/sidebar_workspace.dart

@@ -161,7 +161,7 @@ class _SidebarSwitchWorkspaceButtonState
             builder: (context, state) {
               final currentWorkspace = state.currentWorkspace;
               final workspaces = state.workspaces;
-              if (currentWorkspace == null || workspaces.isEmpty) {
+              if (currentWorkspace == null) {
                 return const SizedBox.shrink();
               }
               return WorkspacesMenu(