websocket - WIP

apps/server/src/ws/services/excalidraw-collab.service.ts

@@ -0,0 +1,91 @@
+import { Injectable } from '@nestjs/common';
+import { Server, Socket } from 'socket.io';
+import { ExcalidrawFollowPayload } from '../types/excalidraw.types';
+
+@Injectable()
+export class ExcalidrawCollabService {
+  async handleJoinRoom(
+    client: Socket,
+    server: Server,
+    roomId: string,
+  ): Promise<void> {
+    await client.join(roomId);
+
+    const sockets = await server.in(roomId).fetchSockets();
+
+    if (sockets.length <= 1) {
+      server.to(client.id).emit('first-in-room');
+    } else {
+      client.broadcast.to(roomId).emit('new-user', client.id);
+    }
+
+    server.in(roomId).emit(
+      'room-user-change',
+      sockets.map((socket) => socket.id),
+    );
+  }
+
+  handleServerBroadcast(
+    client: Socket,
+    roomId: string,
+    encryptedData: ArrayBuffer,
+    iv: Uint8Array,
+  ): void {
+    client.broadcast.to(roomId).emit('client-broadcast', encryptedData, iv);
+  }
+
+  handleServerVolatileBroadcast(
+    client: Socket,
+    roomId: string,
+    encryptedData: ArrayBuffer,
+    iv: Uint8Array,
+  ): void {
+    client.volatile.broadcast
+      .to(roomId)
+      .emit('client-broadcast', encryptedData, iv);
+  }
+
+  async handleUserFollow(
+    client: Socket,
+    server: Server,
+    payload: ExcalidrawFollowPayload,
+  ): Promise<void> {
+    const roomId = `follow@${payload.userToFollow.socketId}`;
+
+    if (payload.action === 'FOLLOW') {
+      await client.join(roomId);
+    } else {
+      await client.leave(roomId);
+    }
+
+    const sockets = await server.in(roomId).fetchSockets();
+    const followedBy = sockets.map((socket) => socket.id);
+
+    server.to(payload.userToFollow.socketId).emit(
+      'user-follow-room-change',
+      followedBy,
+    );
+  }
+
+  async handleDisconnecting(client: Socket, server: Server): Promise<void> {
+    for (const roomId of Array.from(client.rooms)) {
+      const otherClients = (await server.in(roomId).fetchSockets()).filter(
+        (socket) => socket.id !== client.id,
+      );
+
+      const isFollowRoom = roomId.startsWith('follow@');
+
+      if (!isFollowRoom && otherClients.length > 0) {
+        client.broadcast.to(roomId).emit(
+          'room-user-change',
+          otherClients.map((socket) => socket.id),
+        );
+      }
+
+      if (isFollowRoom && otherClients.length === 0) {
+        const socketId = roomId.replace('follow@', '');
+        server.to(socketId).emit('broadcast-unfollow');
+      }
+    }
+  }
+}

apps/server/src/ws/types/excalidraw.types.ts

@@ -0,0 +1,9 @@
+export type ExcalidrawUserToFollow = {
+  socketId: string;
+  username: string;
+};
+
+export type ExcalidrawFollowPayload = {
+  userToFollow: ExcalidrawUserToFollow;
+  action: 'FOLLOW' | 'UNFOLLOW';
+};

apps/server/src/ws/ws.gateway.ts

@@ -1,6 +1,7 @@
 import {
   MessageBody,
   OnGatewayConnection,
+  OnGatewayDisconnect,
   SubscribeMessage,
   WebSocketGateway,
   WebSocketServer,
@@ -11,17 +12,23 @@ import { JwtPayload, JwtType } from '../core/auth/dto/jwt-payload';
 import { OnModuleDestroy } from '@nestjs/common';
 import { SpaceMemberRepo } from '@docmost/db/repos/space/space-member.repo';
 import * as cookie from 'cookie';
+import { ExcalidrawCollabService } from './services/excalidraw-collab.service';
+import { ExcalidrawFollowPayload } from './types/excalidraw.types';
 
 @WebSocketGateway({
   cors: { origin: '*' },
   transports: ['websocket'],
 })
-export class WsGateway implements OnGatewayConnection, OnModuleDestroy {
+export class WsGateway
+  implements OnGatewayConnection, OnGatewayDisconnect, OnModuleDestroy
+{
   @WebSocketServer()
   server: Server;
+
   constructor(
     private tokenService: TokenService,
     private spaceMemberRepo: SpaceMemberRepo,
+    private excalidrawCollabService: ExcalidrawCollabService,
   ) {}
 
   async handleConnection(client: Socket, ...args: any[]): Promise<void> {
@@ -41,6 +48,8 @@ export class WsGateway implements OnGatewayConnection, OnModuleDestroy {
       const spaceRooms = userSpaceIds.map((id) => this.getSpaceRoomName(id));
 
       client.join([workspaceRoom, ...spaceRooms]);
+
+      this.server.to(client.id).emit('init-room');
     } catch (err) {
       client.emit('Unauthorized');
       client.disconnect();
@@ -66,9 +75,15 @@ export class WsGateway implements OnGatewayConnection, OnModuleDestroy {
   }
 
   @SubscribeMessage('join-room')
-  handleJoinRoom(client: Socket, @MessageBody() roomName: string): void {
-    // if room is a space, check if user has permissions
-    //client.join(roomName);
+  async handleJoinRoom(
+    client: Socket,
+    @MessageBody() roomId: string,
+  ): Promise<void> {
+    await this.excalidrawCollabService.handleJoinRoom(
+      client,
+      this.server,
+      roomId,
+    );
   }
 
   @SubscribeMessage('leave-room')
@@ -76,6 +91,48 @@ export class WsGateway implements OnGatewayConnection, OnModuleDestroy {
     client.leave(roomName);
   }
 
+  @SubscribeMessage('server-broadcast')
+  handleServerBroadcast(
+    client: Socket,
+    [roomId, encryptedData, iv]: [string, ArrayBuffer, Uint8Array],
+  ): void {
+    this.excalidrawCollabService.handleServerBroadcast(
+      client,
+      roomId,
+      encryptedData,
+      iv,
+    );
+  }
+
+  @SubscribeMessage('server-volatile-broadcast')
+  handleServerVolatileBroadcast(
+    client: Socket,
+    [roomId, encryptedData, iv]: [string, ArrayBuffer, Uint8Array],
+  ): void {
+    this.excalidrawCollabService.handleServerVolatileBroadcast(
+      client,
+      roomId,
+      encryptedData,
+      iv,
+    );
+  }
+
+  @SubscribeMessage('user-follow')
+  async handleUserFollow(
+    client: Socket,
+    @MessageBody() payload: ExcalidrawFollowPayload,
+  ): Promise<void> {
+    await this.excalidrawCollabService.handleUserFollow(
+      client,
+      this.server,
+      payload,
+    );
+  }
+
+  async handleDisconnect(client: Socket): Promise<void> {
+    await this.excalidrawCollabService.handleDisconnecting(client, this.server);
+  }
+
   onModuleDestroy() {
     if (this.server) {
       this.server.close();

apps/server/src/ws/ws.module.ts

@@ -1,9 +1,10 @@
 import { Module } from '@nestjs/common';
 import { WsGateway } from './ws.gateway';
 import { TokenModule } from '../core/auth/token.module';
+import { ExcalidrawCollabService } from './services/excalidraw-collab.service';
 
 @Module({
   imports: [TokenModule],
-  providers: [WsGateway],
+  providers: [WsGateway, ExcalidrawCollabService],
 })
 export class WsModule {}