feat(routes): implement lazy loading and suspense fallback for route components

- Refactored account setup, admin center, reporting, and settings routes to utilize React's lazy loading for improved performance.
- Wrapped route components in Suspense with a fallback UI to enhance user experience during loading states.
- Removed unused drag-and-drop CSS file to clean up the codebase.

worklenz-frontend/src/app/routes/account-setup-routes.tsx

@@ -1,9 +1,15 @@
 import { RouteObject } from 'react-router-dom';
-import AccountSetup from '@/pages/account-setup/account-setup';
+import { lazy, Suspense } from 'react';
+import { SuspenseFallback } from '@/components/suspense-fallback/suspense-fallback';
+const AccountSetup = lazy(() => import('@/pages/account-setup/account-setup'));
 
 const accountSetupRoute: RouteObject = {
   path: '/worklenz/setup',
-  element: <AccountSetup />,
+  element: (
+    <Suspense fallback={<SuspenseFallback />}>
+      <AccountSetup />
+    </Suspense>
+  ),
 };
 
 export default accountSetupRoute;

worklenz-frontend/src/app/routes/admin-center-routes.tsx

@@ -1,8 +1,10 @@
 import { RouteObject } from 'react-router-dom';
+import { Suspense } from 'react';
 import AdminCenterLayout from '@/layouts/admin-center-layout';
 import { adminCenterItems } from '@/pages/admin-center/admin-center-constants';
 import { Navigate } from 'react-router-dom';
 import { useAuthService } from '@/hooks/useAuth';
+import { SuspenseFallback } from '@/components/suspense-fallback/suspense-fallback';
 
 const AdminCenterGuard = ({ children }: { children: React.ReactNode }) => {
   const isOwnerOrAdmin = useAuthService().isOwnerOrAdmin();
@@ -24,7 +26,11 @@ const adminCenterRoutes: RouteObject[] = [
     ),
     children: adminCenterItems.map(item => ({
       path: item.endpoint,
-      element: item.element,
+      element: (
+        <Suspense fallback={<SuspenseFallback />}>
+          {item.element}
+        </Suspense>
+      ),
     })),
   },
 ];

worklenz-frontend/src/app/routes/reporting-routes.tsx

@@ -1,6 +1,8 @@
 import { RouteObject } from 'react-router-dom';
+import { Suspense } from 'react';
 import ReportingLayout from '@/layouts/ReportingLayout';
 import { ReportingMenuItems, reportingsItems } from '@/lib/reporting/reporting-constants';
+import { SuspenseFallback } from '@/components/suspense-fallback/suspense-fallback';
 
 //  function to flatten nested menu items
 const flattenItems = (items: ReportingMenuItems[]): ReportingMenuItems[] => {
@@ -20,7 +22,11 @@ const reportingRoutes: RouteObject[] = [
     element: <ReportingLayout />,
     children: flattenedItems.map(item => ({
       path: item.endpoint,
-      element: item.element,
+      element: (
+        <Suspense fallback={<SuspenseFallback />}>
+          {item.element}
+        </Suspense>
+      ),
     })),
   },
 ];

worklenz-frontend/src/app/routes/settings-routes.tsx

@@ -1,8 +1,10 @@
 import { RouteObject } from 'react-router-dom';
 import { Navigate } from 'react-router-dom';
+import { Suspense } from 'react';
 import SettingsLayout from '@/layouts/SettingsLayout';
 import { settingsItems } from '@/lib/settings/settings-constants';
 import { useAuthService } from '@/hooks/useAuth';
+import { SuspenseFallback } from '@/components/suspense-fallback/suspense-fallback';
 
 const SettingsGuard = ({
   children,
@@ -26,7 +28,11 @@ const settingsRoutes: RouteObject[] = [
     element: <SettingsLayout />,
     children: settingsItems.map(item => ({
       path: item.endpoint,
-      element: <SettingsGuard adminRequired={!!item.adminOnly}>{item.element}</SettingsGuard>,
+      element: (
+        <Suspense fallback={<SuspenseFallback />}>
+          <SettingsGuard adminRequired={!!item.adminOnly}>{item.element}</SettingsGuard>
+        </Suspense>
+      ),
     })),
   },
 ];

worklenz-frontend/src/components/task-management/drag-drop-optimized.css

@@ -1,40 +0,0 @@
-/* MINIMAL DRAG AND DROP CSS - SHOW ONLY TASK NAME */
-
-/* Basic drag handle styling */
-.drag-handle-optimized {
-  cursor: grab;
-  opacity: 0.6;
-  transition: opacity 0.2s ease;
-}
-
-.drag-handle-optimized:hover {
-  opacity: 1;
-}
-
-.drag-handle-optimized:active {
-  cursor: grabbing;
-}
-
-/* Simple drag overlay - just show task name */
-[data-dnd-overlay] {
-  background: white;
-  border: 1px solid #d9d9d9;
-  border-radius: 4px;
-  padding: 8px 12px;
-  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
-  pointer-events: none;
-  z-index: 9999;
-}
-
-/* Dark mode support for drag overlay */
-.dark [data-dnd-overlay],
-[data-theme="dark"] [data-dnd-overlay] {
-  background: #1f1f1f;
-  border-color: #404040;
-  color: white;
-}
-
-/* Hide drag handle during drag */
-[data-dnd-dragging="true"] .drag-handle-optimized {
-  opacity: 0;
-}

worklenz-frontend/src/components/task-management/task-list-board.tsx

@@ -27,6 +27,8 @@ import {
   fetchTasksV3,
   selectTaskGroupsV3,
   selectCurrentGroupingV3,
+  fetchSubTasks,
+  toggleTaskExpansion,
 } from '@/features/task-management/task-management.slice';
 import {
   selectTaskGroups,

worklenz-frontend/src/features/task-management/task-management.slice.ts

@@ -343,6 +343,14 @@ export const moveTaskToGroupWithAPI = createAsyncThunk(
   }
 );
 
+// Add action to update task with subtasks
+export const updateTaskWithSubtasks = createAsyncThunk(
+  'taskManagement/updateTaskWithSubtasks',
+  async ({ taskId, subtasks }: { taskId: string; subtasks: any[] }, { getState }) => {
+    return { taskId, subtasks };
+  }
+);
+
 const taskManagementSlice = createSlice({
   name: 'taskManagement',
   initialState: tasksAdapter.getInitialState(initialState),
@@ -627,8 +635,7 @@ const taskManagementSlice = createSlice({
       return tasksAdapter.getInitialState(initialState);
     },
     toggleTaskExpansion: (state, action: PayloadAction<string>) => {
-      const taskId = action.payload;
+      const task = state.entities[action.payload];
-      const task = state.entities[taskId];
       if (task) {
         task.show_sub_tasks = !task.show_sub_tasks;
       }
@@ -700,6 +707,14 @@ const taskManagementSlice = createSlice({
       })
       .addCase(refreshTaskProgress.rejected, (state, action) => {
         state.error = (action.payload as string) || 'Failed to refresh task progress';
+      })
+      .addCase(updateTaskWithSubtasks.fulfilled, (state, action) => {
+        const { taskId, subtasks } = action.payload;
+        const task = state.entities[taskId];
+        if (task) {
+          task.sub_tasks = subtasks;
+          task.show_sub_tasks = true;
+        }
       });
   },
 });

worklenz-frontend/src/lib/reporting/reporting-constants.ts

@@ -1,11 +1,11 @@
-import React, { ReactNode } from 'react';
+import React, { ReactNode, lazy } from 'react';
-import OverviewReports from '@/pages/reporting/overview-reports/overview-reports';
+const OverviewReports = lazy(() => import('@/pages/reporting/overview-reports/overview-reports'));
-import ProjectsReports from '@/pages/reporting/projects-reports/projects-reports';
+const ProjectsReports = lazy(() => import('@/pages/reporting/projects-reports/projects-reports'));
-import MembersReports from '@/pages/reporting/members-reports/members-reports';
+const MembersReports = lazy(() => import('@/pages/reporting/members-reports/members-reports'));
-import OverviewTimeReports from '@/pages/reporting/timeReports/overview-time-reports';
+const OverviewTimeReports = lazy(() => import('@/pages/reporting/timeReports/overview-time-reports'));
-import ProjectsTimeReports from '@/pages/reporting/timeReports/projects-time-reports';
+const ProjectsTimeReports = lazy(() => import('@/pages/reporting/timeReports/projects-time-reports'));
-import MembersTimeReports from '@/pages/reporting/timeReports/members-time-reports';
+const MembersTimeReports = lazy(() => import('@/pages/reporting/timeReports/members-time-reports'));
-import EstimatedVsActualTimeReports from '@/pages/reporting/timeReports/estimated-vs-actual-time-reports';
+const EstimatedVsActualTimeReports = lazy(() => import('@/pages/reporting/timeReports/estimated-vs-actual-time-reports'));
 
 // Type definition for a menu item
 export type ReportingMenuItems = {

worklenz-frontend/src/lib/settings/settings-constants.ts

@@ -13,20 +13,20 @@ import {
   UserSwitchOutlined,
   BulbOutlined,
 } from '@ant-design/icons';
-import React, { ReactNode } from 'react';
+import React, { ReactNode, lazy } from 'react';
-import ProfileSettings from '../../pages/settings/profile/profile-settings';
+const ProfileSettings = lazy(() => import('../../pages/settings/profile/profile-settings'));
-import NotificationsSettings from '../../pages/settings/notifications/notifications-settings';
+const NotificationsSettings = lazy(() => import('../../pages/settings/notifications/notifications-settings'));
-import ClientsSettings from '../../pages/settings/clients/clients-settings';
+const ClientsSettings = lazy(() => import('../../pages/settings/clients/clients-settings'));
-import JobTitlesSettings from '@/pages/settings/job-titles/job-titles-settings';
+const JobTitlesSettings = lazy(() => import('@/pages/settings/job-titles/job-titles-settings'));
-import LabelsSettings from '../../pages/settings/labels/labels-settings';
+const LabelsSettings = lazy(() => import('../../pages/settings/labels/labels-settings'));
-import CategoriesSettings from '../../pages/settings/categories/categories-settings';
+const CategoriesSettings = lazy(() => import('../../pages/settings/categories/categories-settings'));
-import ProjectTemplatesSettings from '@/pages/settings/project-templates/project-templates-settings';
+const ProjectTemplatesSettings = lazy(() => import('@/pages/settings/project-templates/project-templates-settings'));
-import TaskTemplatesSettings from '@/pages/settings/task-templates/task-templates-settings';
+const TaskTemplatesSettings = lazy(() => import('@/pages/settings/task-templates/task-templates-settings'));
-import TeamMembersSettings from '@/pages/settings/team-members/team-members-settings';
+const TeamMembersSettings = lazy(() => import('@/pages/settings/team-members/team-members-settings'));
-import TeamsSettings from '../../pages/settings/teams/teams-settings';
+const TeamsSettings = lazy(() => import('../../pages/settings/teams/teams-settings'));
-import ChangePassword from '@/pages/settings/change-password/change-password';
+const ChangePassword = lazy(() => import('@/pages/settings/change-password/change-password'));
-import LanguageAndRegionSettings from '@/pages/settings/language-and-region/language-and-region-settings';
+const LanguageAndRegionSettings = lazy(() => import('@/pages/settings/language-and-region/language-and-region-settings'));
-import AppearanceSettings from '@/pages/settings/appearance/appearance-settings';
+const AppearanceSettings = lazy(() => import('@/pages/settings/appearance/appearance-settings'));
 
 // type of menu item in settings sidebar
 type SettingMenuItems = {

worklenz-frontend/src/pages/admin-center/admin-center-constants.ts

@@ -5,12 +5,12 @@ import {
   TeamOutlined,
   UserOutlined,
 } from '@ant-design/icons';
-import React, { ReactNode } from 'react';
+import React, { ReactNode, lazy } from 'react';
-import Overview from './overview/overview';
+const Overview = lazy(() => import('./overview/overview'));
-import Users from './users/users';
+const Users = lazy(() => import('./users/users'));
-import Teams from './teams/teams';
+const Teams = lazy(() => import('./teams/teams'));
-import Billing from './billing/billing';
+const Billing = lazy(() => import('./billing/billing'));
-import Projects from './projects/projects';
+const Projects = lazy(() => import('./projects/projects'));
 
 // type of a menu item in admin center sidebar
 type AdminCenterMenuItems = {

worklenz-frontend/src/pages/projects/projectView/taskList/task-list-table/task-list-table-cells/task-list-task-cell/task-list-task-cell.tsx

@@ -20,7 +20,7 @@ import { setSelectedTaskId, setShowTaskDrawer } from '@/features/task-drawer/tas
 import { useState, useRef, useEffect } from 'react';
 import { useSocket } from '@/socket/socketContext';
 import { SocketEvents } from '@/shared/socket-events';
-import { fetchSubTasks } from '@/features/tasks/tasks.slice';
+import { fetchSubTasks } from '@/features/task-management/task-management.slice';
 
 type TaskListTaskCellProps = {
   task: IProjectTask;

worklenz-frontend/src/pages/projects/projectView/taskList/task-list-table/task-list-table-wrapper/task-list-table-wrapper.tsx

@@ -266,6 +266,7 @@ const TaskListTableWrapper = ({
               tableId={tableId}
               activeId={activeId}
               groupBy={groupBy}
+              isOver={isOver}
             />
           </Collapsible>
         </Flex>

worklenz-frontend/src/pages/projects/projectView/taskList/task-list-table/task-list-table.tsx

@@ -32,7 +32,7 @@ import {
   sortableKeyboardCoordinates,
 } from '@dnd-kit/sortable';
 import { createPortal } from 'react-dom';
-import { DragEndEvent } from '@dnd-kit/core';
+import { DragOverEvent } from '@dnd-kit/core';
 import { List, Card, Avatar, Dropdown, Empty, Divider, Button } from 'antd';
 import dayjs from 'dayjs';
 
@@ -90,6 +90,7 @@ interface TaskListTableProps {
   tableId: string;
   activeId?: string | null;
   groupBy?: string;
+  isOver?: boolean; // Add this line
 }
 
 interface DraggableRowProps {
@@ -1291,6 +1292,7 @@ const TaskListTable: React.FC<TaskListTableProps> = ({ taskList, tableId, active
 
   // Add drag state
   const [dragActiveId, setDragActiveId] = useState<string | null>(null);
+  const [placeholderIndex, setPlaceholderIndex] = useState<number | null>(null);
 
   // Configure sensors for drag and drop
   const sensors = useSensors(
@@ -1640,6 +1642,7 @@ const TaskListTable: React.FC<TaskListTableProps> = ({ taskList, tableId, active
   const handleDragEnd = (event: DragEndEvent) => {
     const { active, over } = event;
     setDragActiveId(null);
+    setPlaceholderIndex(null); // Reset placeholder index
 
     if (!over || !active || active.id === over.id) {
       return;
@@ -1794,6 +1797,7 @@ const TaskListTable: React.FC<TaskListTableProps> = ({ taskList, tableId, active
         sensors={sensors}
         onDragStart={handleDragStart}
         onDragEnd={handleDragEnd}
+        onDragOver={handleDragOver} // Add this line
         autoScroll={false} // Disable auto-scroll animations
       >
         <SortableContext
@@ -1858,12 +1862,22 @@ const TaskListTable: React.FC<TaskListTableProps> = ({ taskList, tableId, active
                 {displayTasks && displayTasks.length > 0 ? (
                   displayTasks
                     .filter(task => task?.id) // Filter out tasks without valid IDs
-                    .map(task => {
+                    .map((task, index) => {
                       const updatedTask = findTaskInGroups(task.id || '') || task;
+                      const isDraggingCurrent = dragActiveId === updatedTask.id;
 
                       return (
                         <React.Fragment key={updatedTask.id}>
-                          {renderTaskRow(updatedTask)}
+                          {placeholderIndex === index && (
+                            <tr className="placeholder-row">
+                              <td colSpan={visibleColumns.length + 2}>
+                                <div className="h-10 border-2 border-dashed border-blue-400 rounded-md flex items-center justify-center text-blue-500">
+                                  Drop task here
+                                </div>
+                              </td>
+                            </tr>
+                          )}
+                          {!isDraggingCurrent && renderTaskRow(updatedTask)}
                           {updatedTask.show_sub_tasks && (
                             <>
                               {updatedTask?.sub_tasks?.map(subtask =>
@@ -1910,6 +1924,15 @@ const TaskListTable: React.FC<TaskListTableProps> = ({ taskList, tableId, active
                     </td>
                   </tr>
                 )}
+                {placeholderIndex === displayTasks.length && (
+                  <tr className="placeholder-row">
+                    <td colSpan={visibleColumns.length + 2}>
+                      <div className="h-10 border-2 border-dashed border-blue-400 rounded-md flex items-center justify-center text-blue-500">
+                        Drop task here
+                      </div>
+                    </td>
+                  </tr>
+                )}
               </tbody>
             </table>
           </div>