feat: Group chat and push notifications

- Add group chat tables (chat_groups, chat_group_members, group_messages)
- Add push subscriptions table for web push notifications
- Add group service, controller, routes
- Add push service, controller, routes
- Integrate push notifications with todos, messages, group messages

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

src/services/todo.service.js

@@ -3,6 +3,8 @@ import { todos, todoUsers, notes, projects, companies, users } from '../db/schem
 import { eq, desc, ilike, or, and, inArray } from 'drizzle-orm';
 import { NotFoundError } from '../utils/errors.js';
 import { getAccessibleResourceIds } from '../middlewares/auth/resourceAccessMiddleware.js';
+import { sendPushNotificationToUsers } from './push.service.js';
+import { logger } from '../utils/logger.js';
 
 /**
  * Get all todos
@@ -217,6 +219,25 @@ export const createTodo = async (userId, data) => {
     });
   }
 
+  // Send push notifications to assigned users (excluding creator)
+  if (assignedUserIds && Array.isArray(assignedUserIds) && assignedUserIds.length > 0) {
+    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);
+    }
+  }
+
   return newTodo;
 };
 
@@ -224,8 +245,9 @@ export const createTodo = async (userId, data) => {
  * Update todo
  * @param {string} todoId - ID of todo to update
  * @param {object} data - Updated data including assignedUserIds array
+ * @param {string} updatedByUserId - ID of user making the update (for notifications)
  */
-export const updateTodo = async (todoId, data) => {
+export const updateTodo = async (todoId, data, updatedByUserId = null) => {
   const todo = await getTodoById(todoId);
 
   const { title, description, projectId, companyId, assignedUserIds, status, priority, dueDate } = data;
@@ -294,6 +316,13 @@ export const updateTodo = async (todoId, data) => {
 
   // Update assigned users if provided
   if (assignedUserIds !== undefined) {
+    // Get existing assigned users before deleting
+    const existingAssignments = await db
+      .select({ userId: todoUsers.userId })
+      .from(todoUsers)
+      .where(eq(todoUsers.todoId, todoId));
+    const existingUserIds = existingAssignments.map(a => a.userId);
+
     // Delete existing assignments
     await db.delete(todoUsers).where(eq(todoUsers.todoId, todoId));
 
@@ -302,10 +331,34 @@ export const updateTodo = async (todoId, data) => {
       const todoUserInserts = assignedUserIds.map((userId) => ({
         todoId: todoId,
         userId: userId,
-        assignedBy: null, // We don't track who made the update
+        assignedBy: updatedByUserId,
       }));
 
       await db.insert(todoUsers).values(todoUserInserts);
+
+      // Find newly assigned users (not in existing list)
+      const newlyAssignedUserIds = assignedUserIds.filter(
+        id => !existingUserIds.includes(id)
+      );
+
+      // 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);
+        }
+      }
     }
   }