Merge pull request #4 from jovinjijo/feature-websockets

Realtime updates in UI

.editorconfig

@@ -1,7 +1,7 @@
 root = true
 
 [*]
-end_of_line = lf
+end_of_line = crlf
 insert_final_newline = true
 
 [*.{js,json,ts,tsx,.yml}]

packages/api/index.ts

@@ -1,16 +1,21 @@
 import app from './src/app';
+import { SocketService } from './src/services/SocketService';
 import { initMarket } from './src/util/Methods';
+import { createServer } from 'http';
 
-initMarket();
+const server = createServer(app);
+const socketService = new SocketService(server);
+
+initMarket(socketService);
 
 /**
  * Start Express server.
  */
-const server = app.listen(app.get('port'), () => {
+server.listen(app.get('port'), () => {
     console.log('  App is running at http://localhost:%d in %s mode', app.get('port'), app.get('env'));
     console.log('  Press CTRL-C to stop\n');
 });
 
-export { server };
-export { UserStoreItemDetails } from './src/models/User';
+export { UserStoreItemDetails, UserDetails } from './src/models/User';
 export { OrderStoreDetails } from './src/models/Order';
+export { LtpUpdate, OrderUpdate } from './src/services/NotificationService';

packages/api/package.json

@@ -10,7 +10,7 @@
     "test": "jest --collectCoverage --testTimeout 20000",
     "lint": "eslint '**/*.{js,ts}' --fix",
     "precommit": "lint-staged && yarn test",
-    "start": "nodemon build/server.js"
+    "start": "nodemon build/index.js"
   },
   "keywords": [
     "stockexchange",
@@ -28,18 +28,21 @@
     "compression": "^1.7.4",
     "express": "^4.17.1",
     "express-session": "^1.17.1",
+    "express-socket.io-session": "^1.3.5",
     "express-validator": "^6.6.1",
     "method-override": "^3.0.0",
     "socket.io": "^2.3.0"
   },
   "devDependencies": {
-    "@types/jest": "^26.0.13",
     "@types/bcrypt": "^3.0.0",
     "@types/compression": "^1.7.0",
     "@types/express": "^4.17.7",
     "@types/express-session": "^1.17.0",
+    "@types/express-socket.io-session": "^1.3.2",
+    "@types/jest": "^26.0.13",
     "@types/method-override": "^0.0.31",
     "@types/newman": "^5.1.1",
+    "@types/socket.io": "^2.1.11",
     "@typescript-eslint/eslint-plugin": "^3.9.0",
     "@typescript-eslint/parser": "^3.9.0",
     "eslint": "^7.6.0",

packages/api/src/app.ts

@@ -1,7 +1,7 @@
 import express from 'express';
 import compression from 'compression';
 import bodyParser from 'body-parser';
-import session from 'express-session';
+import expressSession from 'express-session';
 import path from 'path';
 import methodOverride from 'method-override';
 
@@ -20,13 +20,12 @@ app.use(compression());
 app.use(bodyParser.json());
 app.use(bodyParser.urlencoded({ extended: true }));
 
-app.use(
-    session({
-        resave: true,
-        saveUninitialized: true,
-        secret: process.env['SESSION_SECRET'] || '12345678',
-    }),
-);
+const session = expressSession({
+    resave: true,
+    saveUninitialized: true,
+    secret: process.env['SESSION_SECRET'] || '12345678',
+});
+app.use(session);
 
 // If a user is logged in, fill up req.user with user details
 app.use(fillUserData);
@@ -52,3 +51,4 @@ app.use(methodOverride());
 app.use(errorHandler);
 
 export default app;
+export { session };

packages/api/src/models/Order.ts

@@ -14,33 +14,25 @@ import {
     ID,
 } from '@se/core';
 
-type TruncatedOrderDetails =
-    | OrderInput
-    | {
-          id: ID;
-          time: Date;
-      };
+type TruncatedOrderDetails = Omit<OrderInput, 'user'> & {
+    id: ID;
+    time: Date;
+};
 
-type ConfirmedOrderDetails =
-    | TruncatedOrderDetails
-    | {
-          status: OrderStatus.Confirmed;
-          avgSettledPrice: Amount;
-          settledTime: Date;
-      };
+type ConfirmedOrderDetails = TruncatedOrderDetails & {
+    status: OrderStatus.Confirmed;
+    avgSettledPrice: Amount;
+    settledTime: Date;
+};
 
-type PlacedOrderDetails =
-    | TruncatedOrderDetails
-    | {
-          status: OrderStatus.Placed;
-      };
+type PlacedOrderDetails = TruncatedOrderDetails & {
+    status: OrderStatus.Placed;
+};
 
-type PartiallyFilledOrderDetails =
-    | TruncatedOrderDetails
-    | {
-          status: OrderStatus.PartiallyFilled;
-          quantityFilled: Quantity;
-      };
+type PartiallyFilledOrderDetails = TruncatedOrderDetails & {
+    status: OrderStatus.PartiallyFilled;
+    quantityFilled: Quantity;
+};
 
 export type OrderDetails = ConfirmedOrderDetails | PlacedOrderDetails | PartiallyFilledOrderDetails;
 
@@ -81,12 +73,20 @@ export class OrderRepository {
     }
 
     public static getOrderDetails(order: Order): OrderDetails {
+        const orderInput: OrderInput = {
+            ...{
+                quantity: order.quantity,
+                symbol: order.symbol,
+                type: order.type,
+                user: order.user,
+            },
+            ...(order.additionalType === AdditionalOrderType.Market
+                ? { additionalType: AdditionalOrderType.Market }
+                : { additionalType: AdditionalOrderType.Limit, price: order.price }),
+        };
         const orderDetails: TruncatedOrderDetails = {
+            ...{ ...orderInput, user: undefined },
             id: order.id,
-            price: order.price,
-            quantity: order.quantity,
-            symbol: order.symbol,
-            type: order.type,
             time: order.time,
         };
         if (order.status === OrderStatus.Confirmed) {

packages/api/src/models/User.ts

@@ -1,18 +1,24 @@
 import { User, Amount, HoldingsData, IUser } from '@se/core';
 import * as bcrypt from 'bcrypt';
+import { Socket } from 'socket.io';
 import { OrderRepository, OrderStoreDetails } from './Order';
 
 const saltRounds = 10;
 
+export interface WalletDetails {
+    margin: Amount;
+}
+
 export interface UserDetails extends Omit<IUser, 'orders' | 'holdings' | 'name' | 'wallet'> {
     orders: OrderStoreDetails;
     holdings: HoldingsData;
-    wallet: { margin: Amount };
+    wallet: WalletDetails;
 }
 
 export interface UserStoreItem {
     user: User;
     username: string;
+    socket?: Socket;
 }
 
 export interface UserStoreItemDetails extends UserDetails {
@@ -23,7 +29,7 @@ export interface UserStoreItemSensitive extends UserStoreItem {
     password: string;
 }
 export class UserStore {
-    static users: Map<string, UserStoreItemSensitive> = new Map<string, UserStoreItemSensitive>();
+    private static users: Map<string, UserStoreItemSensitive> = new Map<string, UserStoreItemSensitive>();
 
     public static async addUser(
         username: string,
@@ -49,6 +55,7 @@ export class UserStore {
             return {
                 user: user.user,
                 username: user.username,
+                socket: user.socket,
             };
         }
         throw new Error('User not found');
@@ -80,4 +87,13 @@ export class UserStore {
             username: user.username,
         };
     }
+
+    public static setSocketForUser(username: string, socket: Socket): void {
+        const user = this.users.get(username);
+        if (user) {
+            user.socket = socket;
+        } else {
+            throw new Error('User not found');
+        }
+    }
 }

packages/api/src/services/NotificationService.ts

@@ -0,0 +1,36 @@
+import { Amount, Notification, Order, Stock, User } from '@se/core';
+import { OrderDetails, OrderRepository } from '../models/Order';
+import { UserDetails, UserStore } from '../models/User';
+import { SocketService } from './SocketService';
+
+export interface LtpUpdate {
+    stock: Stock;
+    lastTradePrice: Amount;
+    time: Date;
+}
+
+export interface OrderUpdate {
+    user: UserDetails;
+    order: OrderDetails;
+}
+
+export class NotificationService implements Notification {
+    socketService: SocketService;
+    constructor(socketService: SocketService) {
+        this.socketService = socketService;
+    }
+
+    notifyLtpUpdate(stock: Stock, lastTradePrice: Amount, time: Date): void {
+        this.socketService.broadcast('ltpUpdate', { stock, lastTradePrice, time });
+    }
+
+    notifyOrderUpdate(user: User, order: Order): void {
+        const socket = UserStore.findUserByUsername(user.name)?.socket;
+        if (socket) {
+            this.socketService.send(socket, 'orderUpdate', {
+                user: UserStore.getUserDetails(user),
+                order: OrderRepository.getOrderDetails(order),
+            });
+        }
+    }
+}

packages/api/src/services/SocketService.ts

@@ -0,0 +1,27 @@
+import { SocketServer } from '../util/SocketServer';
+import { Server } from 'http';
+import { Socket } from 'socket.io';
+import { UserStore } from '../models/User';
+import { Market } from '@se/core';
+
+export class SocketService extends SocketServer {
+    constructor(server: Server) {
+        super(server, SocketService.onNewConnection);
+    }
+
+    static onNewConnection(socket: Socket): void {
+        try {
+            if (!socket.handshake.session) {
+                throw new Error('User not logged in');
+            } else {
+                const username = socket.handshake.session.userId;
+                if (username) {
+                    UserStore.setSocketForUser(username, socket);
+                    socket.emit('ltpMap', Market.getInstance().getLtpForOrderStores());
+                }
+            }
+        } catch (ex) {
+            socket.disconnect();
+        }
+    }
+}

packages/api/src/util/Methods.ts

@@ -1,9 +1,13 @@
 import { Market, Stock } from '@se/core';
+import { NotificationService } from '../services/NotificationService';
+import { SocketService } from '../services/SocketService';
 
-function initMarket(): void {
+function initMarket(socketService: SocketService): void {
     Market.getInstance().addOrderStore(Stock.TSLA, 500);
     Market.getInstance().addOrderStore(Stock.AMZN, 3000);
     Market.getInstance().addOrderStore(Stock.RIL, 2000);
+
+    Market.getInstance().attachNotification(new NotificationService(socketService));
 }
 
 export { initMarket };

packages/api/src/util/SocketServer.ts

@@ -0,0 +1,24 @@
+import { Server } from 'http';
+import io, { Socket } from 'socket.io';
+import sharedSession from 'express-socket.io-session';
+import { session } from '../app';
+
+export class SocketServer {
+    private socket: SocketIO.Server;
+
+    constructor(server: Server, onNewConnection?: (socket: Socket) => void) {
+        this.socket = io(server);
+        this.socket.use(sharedSession(session, { autoSave: true }));
+        this.socket.on('connection', (socket: Socket) => {
+            if (onNewConnection) onNewConnection(socket);
+        });
+    }
+
+    send(socket: Socket, type: string, data: unknown): void {
+        socket.emit(type, data);
+    }
+
+    broadcast(type: string, data: unknown): void {
+        this.socket.emit(type, data);
+    }
+}

packages/api/tests/user.test.ts

@@ -1,15 +1,19 @@
 import * as newman from 'newman';
 import collection from '../docs/se_api.postman_collection.json';
-import { Server } from 'http';
+import { Server, createServer } from 'http';
 
 import app from '../src/app';
 import { initMarket } from '../src/util/Methods';
+import { SocketService } from '../src/services/SocketService';
 
 let server: Server;
 
 beforeAll((done) => {
-    initMarket();
-    server = app.listen(app.get('port'), () => {
+    server = createServer(app);
+    const socketService = new SocketService(server);
+
+    initMarket(socketService);
+    server.listen(app.get('port'), () => {
         done();
     });
 });