refactor: Extract notification logic from todo.service.js

Create todo-notification.service.js with:
- notifyNewTodoAssignment(): push notification for new todo assignments
- notifyUpdatedTodoAssignment(): push notification for updated assignments

todo.service.js now delegates to the notification service instead of
containing inline push notification logic with error handling.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/services/todo-notification.service.js

@@ -0,0 +1,46 @@
+import { sendPushNotificationToUsers } from './push.service.js';
+import { logger } from '../utils/logger.js';
+
+export const notifyNewTodoAssignment = async (assignedUserIds, title, todoId, excludeUserId) => {
+  if (!assignedUserIds || !Array.isArray(assignedUserIds) || assignedUserIds.length === 0) {
+    return;
+  }
+
+  try {
+    await sendPushNotificationToUsers(
+      assignedUserIds,
+      {
+        title: 'Nová úloha',
+        body: `Bola vám priradená úloha: ${title}`,
+        icon: '/icon-192.png',
+        badge: '/badge-72.png',
+        data: { url: '/todos', todoId },
+      },
+      excludeUserId,
+    );
+  } catch (error) {
+    logger.error('Failed to send push notifications for new todo', error);
+  }
+};
+
+export const notifyUpdatedTodoAssignment = async (newlyAssignedUserIds, title, todoId, excludeUserId) => {
+  if (!newlyAssignedUserIds || newlyAssignedUserIds.length === 0) {
+    return;
+  }
+
+  try {
+    await sendPushNotificationToUsers(
+      newlyAssignedUserIds,
+      {
+        title: 'Priradená úloha',
+        body: `Bola vám priradená úloha: ${title}`,
+        icon: '/icon-192.png',
+        badge: '/badge-72.png',
+        data: { url: '/todos', todoId },
+      },
+      excludeUserId,
+    );
+  } catch (error) {
+    logger.error('Failed to send push notifications for updated todo', error);
+  }
+};

src/services/todo.service.js

@@ -3,8 +3,7 @@ import { todos, todoUsers, notes, projects, companies, users } from '../db/schem
 import { eq, desc, ilike, or, and, inArray, lt, ne, sql } from 'drizzle-orm';
 import { NotFoundError } from '../utils/errors.js';
 import { getAccessibleResourceIds } from '../middlewares/auth/resourceAccessMiddleware.js';
-import { sendPushNotificationToUsers } from './push.service.js';
+import { notifyNewTodoAssignment, notifyUpdatedTodoAssignment } from './todo-notification.service.js';
-import { logger } from '../utils/logger.js';
 import {
   logTodoCreated, logTodoDeleted, logTodoCompleted, logTodoUpdated, logTodoUncompleted,
 } from './audit.service.js';
@@ -213,23 +212,7 @@ export const createTodo = async (userId, data, auditContext = null) => {
   }
 
   // Send push notifications to assigned users (excluding creator)
-  if (assignedUserIds && Array.isArray(assignedUserIds) && assignedUserIds.length > 0) {
+  await notifyNewTodoAssignment(assignedUserIds, title, newTodo.id, userId);
-    try {
-      await sendPushNotificationToUsers(
-        assignedUserIds,
-        {
-          title: 'Nová úloha',
-          body: `Bola vám priradená úloha: ${title}`,
-          icon: '/icon-192.png',
-          badge: '/badge-72.png',
-          data: { url: '/todos', todoId: newTodo.id },
-        },
-        userId // exclude creator
-      );
-    } catch (error) {
-      logger.error('Failed to send push notifications for new todo', error);
-    }
-  }
 
   if (auditContext) {
     await logTodoCreated(auditContext.userId, newTodo.id, newTodo.title, auditContext.ipAddress, auditContext.userAgent);
@@ -333,29 +316,11 @@ export const updateTodo = async (todoId, data, updatedByUserId = null, auditCont
 
       await db.insert(todoUsers).values(todoUserInserts);
 
-      // Find newly assigned users (not in existing list)
+      // Send push notifications to newly assigned users
       const newlyAssignedUserIds = assignedUserIds.filter(
         id => !existingUserIds.includes(id)
       );
-
+      await notifyUpdatedTodoAssignment(newlyAssignedUserIds, updated.title, todoId, updatedByUserId);
-      // Send push notifications to newly assigned users
-      if (newlyAssignedUserIds.length > 0) {
-        try {
-          await sendPushNotificationToUsers(
-            newlyAssignedUserIds,
-            {
-              title: 'Priradená úloha',
-              body: `Bola vám priradená úloha: ${updated.title}`,
-              icon: '/icon-192.png',
-              badge: '/badge-72.png',
-              data: { url: '/todos', todoId: todoId },
-            },
-            updatedByUserId // exclude user making the change
-          );
-        } catch (error) {
-          logger.error('Failed to send push notifications for updated todo', error);
-        }
-      }
     }
   }