sse für live collab eingebaut

listify-api/src/lists/list-realtime.service.ts

@@ -0,0 +1,97 @@
+import { Injectable, MessageEvent } from '@nestjs/common';
+import { Observable, Observer } from 'rxjs';
+import { UserList } from '../list-templates/list-template.types';
+
+export type ListRealtimeEvent =
+  | {
+      type: 'list.snapshot';
+      data: UserList;
+    }
+  | {
+      type: 'list.deleted';
+      data: { listId: string };
+    }
+  | {
+      type: 'heartbeat';
+      data: { at: string };
+    };
+
+@Injectable()
+export class ListRealtimeService {
+  // In-memory SSE fanout for one API process. If the API is scaled horizontally,
+  // replace this map with a shared pub/sub backend while keeping the event shape.
+  private readonly channels = new Map<string, Set<Observer<ListRealtimeEvent>>>();
+
+  /**
+   * Opens an owner-scoped stream. The controller authenticates the request before
+   * calling this method, so subscribers only receive their own list events.
+   */
+  eventsFor(ownerId: string): Observable<MessageEvent> {
+    return new Observable<ListRealtimeEvent>((observer) => {
+      this.addObserver(ownerId, observer);
+
+      // Keep proxies and browsers from treating an otherwise quiet stream as idle.
+      const heartbeatInterval = setInterval(() => {
+        observer.next({
+          type: 'heartbeat',
+          data: { at: new Date().toISOString() },
+        });
+      }, 25_000);
+
+      return () => {
+        clearInterval(heartbeatInterval);
+        this.removeObserver(ownerId, observer);
+      };
+    });
+  }
+
+  publishSnapshot(ownerId: string, list: UserList): void {
+    this.publish(ownerId, {
+      type: 'list.snapshot',
+      data: list,
+    });
+  }
+
+  publishDeleted(ownerId: string, listId: string): void {
+    this.publish(ownerId, {
+      type: 'list.deleted',
+      data: { listId },
+    });
+  }
+
+  private publish(ownerId: string, event: ListRealtimeEvent): void {
+    const observers = this.channels.get(ownerId);
+
+    if (!observers) {
+      return;
+    }
+
+    observers.forEach((observer) => observer.next(event));
+  }
+
+  private addObserver(
+    ownerId: string,
+    observer: Observer<ListRealtimeEvent>,
+  ): void {
+    const observers = this.channels.get(ownerId) ?? new Set();
+    observers.add(observer);
+    this.channels.set(ownerId, observers);
+  }
+
+  private removeObserver(
+    ownerId: string,
+    observer: Observer<ListRealtimeEvent>,
+  ): void {
+    const observers = this.channels.get(ownerId);
+
+    if (!observers) {
+      return;
+    }
+
+    observers.delete(observer);
+
+    if (observers.size === 0) {
+      this.channels.delete(ownerId);
+    }
+  }
+}

listify-api/src/lists/lists.controller.ts

@@ -7,22 +7,27 @@ import {
   Patch,
   Post,
   Req,
+  Sse,
   UnauthorizedException,
   UseGuards,
 } from '@nestjs/common';
+import { Observable } from 'rxjs';
 import { JwtAuthGuard } from '../auth/jwt-auth.guard';
 import { AuthService } from '../auth/auth.service';
 import { CreateListDto } from './dto/create-list.dto';
 import { AddListItemDto, UpdateListItemDto } from './dto/list-item.dto';
 import { UpdateListDto } from './dto/update-list.dto';
+import { ListRealtimeService } from './list-realtime.service';
 import { ListsService } from './lists.service';
 import type { AuthenticatedRequest } from '../auth/auth.types';
+import type { MessageEvent } from '@nestjs/common';
 
 @Controller('lists')
 @UseGuards(JwtAuthGuard)
 export class ListsController {
   constructor(
     private readonly authService: AuthService,
+    private readonly listRealtimeService: ListRealtimeService,
     private readonly listsService: ListsService,
   ) {}
 
@@ -39,6 +44,11 @@ export class ListsController {
     return this.listsService.listLists(this.requireUserId(request));
   }
 
+  @Sse('events')
+  listEvents(@Req() request: AuthenticatedRequest): Observable<MessageEvent> {
+    return this.listRealtimeService.eventsFor(this.requireUserId(request));
+  }
+
   @Get(':listId')
   getList(
     @Req() request: AuthenticatedRequest,

listify-api/src/lists/lists.module.ts

@@ -3,6 +3,7 @@ import { TypeOrmModule } from '@nestjs/typeorm';
 import { AuditModule } from '../audit/audit.module';
 import { AuthModule } from '../auth/auth.module';
 import { ListsController } from './lists.controller';
+import { ListRealtimeService } from './list-realtime.service';
 import { ListsService } from './lists.service';
 import { UserListEntity } from './user-list.entity';
 import { UserListItemEntity } from './user-list-item.entity';
@@ -14,7 +15,7 @@ import { UserListItemEntity } from './user-list-item.entity';
     TypeOrmModule.forFeature([UserListEntity, UserListItemEntity]),
   ],
   controllers: [ListsController],
-  providers: [ListsService],
-  exports: [ListsService],
+  providers: [ListRealtimeService, ListsService],
+  exports: [ListRealtimeService, ListsService],
 })
 export class ListsModule {}

listify-api/src/lists/lists.service.spec.ts

@@ -1,6 +1,7 @@
 import { ForbiddenException, NotFoundException } from '@nestjs/common';
 import { ListTemplate } from '../list-templates/list-template.types';
 import { InMemoryRepository } from '../testing/in-memory-repository';
+import { ListRealtimeService } from './list-realtime.service';
 import { ListsService } from './lists.service';
 import { UserListEntity } from './user-list.entity';
 import { UserListItemEntity } from './user-list-item.entity';
@@ -48,6 +49,57 @@ describe('ListsService', () => {
     await expect(service.listLists('user-1')).resolves.toHaveLength(0);
   });
 
+  it('publishes realtime snapshots and deletions for the owning user', async () => {
+    const realtimeService = {
+      publishDeleted: jest.fn(),
+      publishSnapshot: jest.fn(),
+    } satisfies Partial<ListRealtimeService>;
+    service = new ListsService(
+      new InMemoryRepository<UserListEntity>() as never,
+      new InMemoryRepository<UserListItemEntity>() as never,
+      undefined,
+      realtimeService as never,
+    );
+
+    const list = await service.createList('user-1', {
+      name: 'Live Liste',
+      kind: 'todo',
+    });
+    const withItem = await service.addItem('user-1', list.id, {
+      title: 'Eintrag',
+    });
+
+    await service.updateItem(
+      'user-1',
+      list.id,
+      withItem.items[0].id,
+      { checked: true },
+      'Test User',
+    );
+    await service.deleteList('user-1', list.id);
+
+    expect(realtimeService.publishSnapshot).toHaveBeenCalledWith(
+      'user-1',
+      expect.objectContaining({ id: list.id, name: 'Live Liste' }),
+    );
+    expect(realtimeService.publishSnapshot).toHaveBeenCalledWith(
+      'user-1',
+      expect.objectContaining({
+        id: list.id,
+        items: [
+          expect.objectContaining({
+            id: withItem.items[0].id,
+            checked: true,
+          }),
+        ],
+      }),
+    );
+    expect(realtimeService.publishDeleted).toHaveBeenCalledWith(
+      'user-1',
+      list.id,
+    );
+  });
+
   it('adds, updates, checks and deletes list items', async () => {
     const list = await service.createList('user-1', {
       name: 'Einkauf',

listify-api/src/lists/lists.service.ts

@@ -18,6 +18,7 @@ import {
 import { CreateListFromTemplateDto } from '../list-templates/dto/create-list-from-template.dto';
 import { AddListItemDto, UpdateListItemDto } from './dto/list-item.dto';
 import { CreateListDto } from './dto/create-list.dto';
+import { ListRealtimeService } from './list-realtime.service';
 import { UpdateListDto } from './dto/update-list.dto';
 import { UserListEntity } from './user-list.entity';
 import { UserListItemEntity } from './user-list-item.entity';
@@ -31,6 +32,8 @@ export class ListsService {
     private readonly listItemsRepository: Repository<UserListItemEntity>,
     @Optional()
     private readonly auditLogService?: AuditLogService,
+    @Optional()
+    private readonly listRealtimeService?: ListRealtimeService,
   ) {}
 
   async createList(ownerId: string, createDto: CreateListDto): Promise<UserList> {
@@ -56,7 +59,10 @@ export class ListsService {
       },
     });
 
-    return this.toUserList(savedList);
+    const userList = this.toUserList(savedList);
+    this.listRealtimeService?.publishSnapshot(ownerId, userList);
+
+    return userList;
   }
 
   async createListFromTemplate(
@@ -108,7 +114,10 @@ export class ListsService {
       },
     });
 
-    return this.toUserList(savedList);
+    const userList = this.toUserList(savedList);
+    this.listRealtimeService?.publishSnapshot(ownerId, userList);
+
+    return userList;
   }
 
   async listLists(ownerId: string): Promise<UserList[]> {
@@ -160,7 +169,10 @@ export class ListsService {
       },
     });
 
-    return this.toUserList(savedList);
+    const userList = this.toUserList(savedList);
+    this.listRealtimeService?.publishSnapshot(ownerId, userList);
+
+    return userList;
   }
 
   async deleteList(ownerId: string, listId: string): Promise<{ message: string }> {
@@ -180,6 +192,8 @@ export class ListsService {
       metadata,
     });
 
+    this.listRealtimeService?.publishDeleted(ownerId, listId);
+
     return { message: 'List deleted.' };
   }
 
@@ -209,7 +223,10 @@ export class ListsService {
       },
     });
 
-    return this.getList(ownerId, listId);
+    const updatedList = await this.getList(ownerId, listId);
+    this.listRealtimeService?.publishSnapshot(ownerId, updatedList);
+
+    return updatedList;
   }
 
   async updateItem(
@@ -279,7 +296,10 @@ export class ListsService {
       },
     });
 
-    return this.getList(ownerId, listId);
+    const updatedList = await this.getList(ownerId, listId);
+    this.listRealtimeService?.publishSnapshot(ownerId, updatedList);
+
+    return updatedList;
   }
 
   async deleteItem(
@@ -315,7 +335,10 @@ export class ListsService {
       },
     });
 
-    return this.getList(ownerId, listId);
+    const updatedList = await this.getList(ownerId, listId);
+    this.listRealtimeService?.publishSnapshot(ownerId, updatedList);
+
+    return updatedList;
   }
 
   private async findOwnedList(