Setting up the socket listeners

SocketManager.ts

import { joinRoom, saveRoomMessage } from "./DynamoPuts";

class SocketManager {
  io: SocketIO.Server;
  dynamoEnabled: boolean;
  redisEnabled: boolean;
  dynamoEnabled: boolean;

  constructor(server: http.Server, config: IServerConfig) {
    this.generateSocketServer(server);
    this.registerSocketListeners();
    this.dynamoEnabled = config.configuredDynamo;
  }

  registerSocketListeners = () => {
    // When the socket initially connects
    this.io.on("connect", async (socket: ICustomSocket) => {
      // Join user channel, so we can send messages directly to this user.
      socket.join(`user${socket.username}`);

      // If the user has logged in before, set them as online.
      if (this.redisEnabled && socket.username && socket.sessionId) {
        this.sessionStore.saveSession(socket.sessionId, {
          username: socket.username,
          connected: `true`
        });
        socket.emit("session", {
          sessionId: socket.sessionId,
          username: socket.username
        });
        // Put into online user list
        this.pubClient.lpush(`onlineUsers`, socket.username);
        this.updateOnlineUsers();
      }

      socket.on("message", async (m: ISocketMessage) => {
        // Sent to room only
        this.io.to(m.room).emit("message", m);
        if (this.dynamoEnabled) {
          saveRoomMessage(m);
        }
      });

      socket.on("disconnect", () => {
        if (socket.username && socket.sessionId) {
          if (this.redisEnabled) {
            this.sessionStore.saveSession(socket.sessionId, {
              username: socket.username,
              connected: `false`
            });
            this.pubClient.LREM(`onlineUsers`, 1, socket.username);
          }
          this.updateOnlineUsers();
        }
      });

      socket.on("joinRoom", async (data: IRoomData) => {
        socket.join(data.roomId);

        if (this.dynamoEnabled && socket.username) {
          joinRoom(data.roomId, data.userId, socket.username, false);
          // Dynamo query room messages for newly connected user
          const roomMessageList = await getMessagesForRoom(data.roomId);
          socket.emit("messageList", roomMessageList);
          this.updateUsersInRoom(data.roomId);
        }
      });
    });
  };
}