fix(backend): correct user permissions, photo urls, events, etc.

Signed-off-by: Erik Michelson <github@erik.michelson.eu>

backend/src/api/private/notes/notes.controller.ts

@@ -185,11 +185,11 @@ export class NotesController {
   @UseInterceptors(GetNoteIdInterceptor)
   @RequirePermission(RequiredPermission.OWNER)
   async setUserPermission(
-    @RequestUserId() userId: number,
     @RequestNoteId() noteId: number,
     @Param('username') username: NoteUserPermissionUpdateDto['username'],
     @Body('canEdit') canEdit: NoteUserPermissionUpdateDto['canEdit'],
   ): Promise<NotePermissionsDto> {
+    const userId = await this.userService.getUserIdByUsername(username);
     await this.permissionService.setUserPermission(noteId, userId, canEdit);
     return await this.noteService.toNotePermissionsDto(noteId);
   }
@@ -198,12 +198,11 @@ export class NotesController {
   @RequirePermission(RequiredPermission.OWNER)
   @Delete(':noteAlias/metadata/permissions/users/:username')
   async removeUserPermission(
-    @RequestUserId() userId: number,
     @RequestNoteId() noteId: number,
     @Param('username') username: NoteUserPermissionEntryDto['username'],
   ): Promise<NotePermissionsDto> {
-    // TODO Fix this removing wrong user permission!
     try {
+      const userId = await this.userService.getUserIdByUsername(username);
       await this.permissionService.removeUserPermission(noteId, userId);
       return await this.noteService.toNotePermissionsDto(noteId);
     } catch (e) {

backend/src/api/private/users/users.controller.ts

@@ -34,7 +34,7 @@ export class UsersController {
     const userExists = await this.userService.isUsernameTaken(
       usernameCheck.username,
     );
-    // TODO Check if username is blocked
+    // TODO Check if username is blocked (https://github.com/hedgedoc/hedgedoc/issues/5794)
     return { usernameAvailable: !userExists };
   }
 

backend/src/auth/ldap/ldap.service.ts

@@ -109,8 +109,9 @@ export class LdapService {
             username: username,
             id: userInfo[ldapConfig.userIdField],
             displayName: userInfo[ldapConfig.displayNameField] ?? username,
-            photoUrl: null, // TODO LDAP stores images as binaries,
+            photoUrl: null,
-            // we need to convert them into a data-URL or alike
+            // TODO LDAP stores images as binaries, we need to upload them to the media backend
+            // https://github.com/hedgedoc/hedgedoc/issues/5032
           });
         },
       );

backend/src/events.ts

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ * SPDX-FileCopyrightText: 2025 The HedgeDoc developers (see AUTHORS file)
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
@@ -29,8 +29,17 @@ export enum NoteEvent {
    *   noteId: The id of the {@link Note}, which is being deleted.
    */
   DELETION = 'note.deletion',
+
+  /**
+   * Event triggered when the realtime note needs to be closed, e.g. when external updates are made to the note.
+   * Payload:
+   *   noteId: The id of the {@link Note}, which should be closed.
+   */
+  CLOSE_REALTIME = 'note.close_realtime',
 }
 
 export interface NoteEventMap extends EventMap {
   [NoteEvent.PERMISSION_CHANGE]: (noteId: number) => void;
+  [NoteEvent.DELETION]: (noteId: number) => void;
+  [NoteEvent.CLOSE_REALTIME]: (noteId: number) => void;
 }

backend/src/notes/note.service.ts

@@ -43,7 +43,7 @@ import {
   MaximumDocumentLengthExceededError,
   NotInDBError,
 } from '../errors/errors';
-import { NoteEventMap } from '../events';
+import { NoteEvent, NoteEventMap } from '../events';
 import { GroupsService } from '../groups/groups.service';
 import { ConsoleLoggerService } from '../logger/console-logger.service';
 import { PermissionService } from '../permissions/permission.service';
@@ -265,14 +265,13 @@ export class NoteService {
    * @throws {NotInDBError} if there is no note with this id
    */
   async deleteNote(noteId: Note[FieldNameNote.id]): Promise<void> {
-    // TODO Disconnect realtime clients first
+    this.eventEmitter.emit(NoteEvent.DELETION, noteId);
     const numberOfDeletedNotes = await this.knex(TableNote)
       .where(FieldNameNote.id, noteId)
       .delete();
     if (numberOfDeletedNotes === 0) {
       throw new NotInDBError(`There is no note with the to delete.`);
     }
-    // TODO Message realtime clients
   }
 
   /**
@@ -285,9 +284,8 @@ export class NoteService {
    * @throws {NotInDBError} there is no note with this id or aliases
    */
   async updateNote(noteId: number, noteContent: string): Promise<void> {
-    // TODO Disconnect realtime clients first
+    this.eventEmitter.emit(NoteEvent.CLOSE_REALTIME, noteId);
     await this.revisionsService.createRevision(noteId, noteContent);
-    // TODO Reload realtime note
   }
 
   /**

backend/src/realtime/realtime-note/realtime-note.service.ts

@@ -151,4 +151,13 @@ export class RealtimeNoteService implements BeforeApplicationShutdown {
       realtimeNote.announceNoteDeletion();
     }
   }
+
+  @OnEvent(NoteEvent.CLOSE_REALTIME)
+  public closeRealtimeNote(noteId: number): void {
+    const realtimeNote = this.realtimeNoteStore.find(noteId);
+    if (realtimeNote) {
+      this.saveRealtimeNote(realtimeNote);
+      realtimeNote.destroy();
+    }
+  }
 }

backend/src/users/users.service.ts

@@ -16,6 +16,7 @@ import {
   User,
 } from '@hedgedoc/database';
 import { BadRequestException, Injectable } from '@nestjs/common';
+import { createHash } from 'crypto';
 import { Knex } from 'knex';
 import { InjectConnection } from 'nest-knexjs';
 import { v4 as uuidv4 } from 'uuid';
@@ -68,16 +69,19 @@ export class UsersService {
           [FieldNameUser.username]: username,
           [FieldNameUser.displayName]: displayName,
           [FieldNameUser.email]: email ?? null,
-          [FieldNameUser.photoUrl]: photoUrl ?? null,
+          [FieldNameUser.photoUrl]: this.generatePhotoUrl(
+            username,
+            email,
+            photoUrl,
+          ),
           // TODO Use generatePhotoUrl method to generate a random avatar image
           [FieldNameUser.guestUuid]: null,
-          [FieldNameUser.authorStyle]: 0,
+          [FieldNameUser.authorStyle]: this.generateAuthorStyleIndex(username),
-          // FIXME Set unique authorStyle per user
         },
         [FieldNameUser.id],
       );
       if (newUsers.length !== 1) {
-        throw new Error();
+        throw new Error('User was not added to the database');
       }
       return newUsers[0][FieldNameUser.id];
     } catch {
@@ -105,8 +109,7 @@ export class UsersService {
         [FieldNameUser.email]: null,
         [FieldNameUser.photoUrl]: null,
         [FieldNameUser.guestUuid]: uuid,
-        [FieldNameUser.authorStyle]: 0,
+        [FieldNameUser.authorStyle]: this.generateAuthorStyleIndex(uuid),
-        // FIXME Set unique authorStyle per user
       },
       [FieldNameUser.id],
     );
@@ -228,7 +231,7 @@ export class UsersService {
    * @return The found user object
    * @throws {NotInDBError} if the user could not be found
    */
-  async getUserIdByUsername(username: string): Promise<User[FieldNameUser.id]> {
+  async getUserIdByUsername(username: string): Promise<number> {
     const userId = await this.knex(TableUser)
       .select(FieldNameUser.id)
       .where(FieldNameUser.username, username)
@@ -307,21 +310,47 @@ export class UsersService {
   }
 
   /**
-   * Extract the photoUrl of the user or falls back to libravatar if enabled
+   * Generates the photo url for a user.
+   * When a valid photoUrl is provided, it will be used.
+   * When an email address is provided and libravatar is enabled, this will be used.
+   * Otherwise, a random image will be generated based on the username.
    *
-   * @param user The user of which to get the photo url
+   * @param username The username to use as a seed when generating a random avatar
-   * @return A URL to the user's profile picture. If the user has no photo and libravatar support is enabled,
+   * @param email The email address of the user for using livbravatar if configured
-   * a URL to that is returned. Otherwise, undefined is returned to indicate that the frontend needs to generate
+   * @param photoUrl The user-provided photo URL
-   * a random avatar image based on the username.
+   * @return A URL to the user's profile picture.
    */
-  getPhotoUrl(user: User): string | undefined {
+  private generatePhotoUrl(
-    if (user[FieldNameUser.photoUrl]) {
+    username: string,
-      return user[FieldNameUser.photoUrl];
+    email: string | null,
-    } else {
+    photoUrl: string | null,
-      // TODO If libravatar is enabled and the user has an email address, use it to fetch the profile picture from there
+  ): string {
-      //  Otherwise return undefined to let the frontend generate a random avatar image (#5010)
+    if (photoUrl && URL.canParse(photoUrl)) {
-      return undefined;
+      return photoUrl;
     }
+    if (email && email.length > 0) {
+      // TODO Add config option to enable or disable libravatar
+      const hash = createHash('sha256')
+        .update(email.toLowerCase())
+        .digest('hex');
+      return `https://seccdn.libravatar.org/avatar/${hash}`;
+    }
+    // TODO Generate random fallback image (data URL) with the username as seed
+    return 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAA1JREFUGFdj+L+E8T8ABu4CpDyuE+YAAAAASUVORK5CYII=';
+  }
+
+  /**
+   * Creates a random author style index based on a hashing of the username
+   *
+   * @param username The username is used as input for the hash
+   * @return An index between 0 and 8 (including 0 and 8)
+   */
+  private generateAuthorStyleIndex(username: string): number {
+    let hash = 0;
+    for (let i = 0; i < username.length; i++) {
+      hash = username.charCodeAt(i) + ((hash << 5) - hash);
+    }
+    return Math.abs(hash % 9);
   }
 
   /**