Resolve "Backend nice-to-haves"

backend/src/controllers/serverController.ts

+import { Request, Response } from 'express';
+
+export const heartbeat = async (req: Request, res: Response): Promise<void> => {
+  res.status(200).send('Server is alive');
+};

backend/src/functions/disposeInactiveGames.ts

+import { GameHandler } from '../gameHandler';
+import { log } from './console';
+
+export function disposeInactiveGames() {
+  const gameHandler = GameHandler.getInstance();
+
+  // loop through all games
+  gameHandler.getGames().forEach((game) => {
+    // if game is inactive for 10 minutes
+    if (Date.now() - game.getLastActionTimeStamp() > 10 * 60 * 1000) {
+      // dispose game and lobby
+      log(
+        'removing inactive game in lobby:' +
+          game.lobby.id +
+          ' containing users:' +
+          game.lobby
+            .getUsers()
+            .map((u) => u.username)
+            .join(', ')
+      );
+      gameHandler.removeLobby(game.lobby);
+      gameHandler.removeGame(game);
+    }
+  });
+}

backend/src/index.ts

@@ -5,8 +5,10 @@ import lobbyRoutes from './routes/lobbyRoutes';
 import userRoutes from './routes/userRoutes';
 import gameRoutes from './routes/gameRoutes';
 import highscoreRoutes from './routes/highscoreRoutes';
+import serverRoutes from './routes/serverRoutes';
 import { log } from './functions/console';
 import { welcome } from './functions/welcomeScreen';
+import { disposeInactiveGames } from './functions/disposeInactiveGames';
 
 new GameHandler(); // singleton ;)
 
@@ -23,6 +25,7 @@ app.use('/lobby', lobbyRoutes);
 app.use('/user', userRoutes);
 app.use('/game', gameRoutes);
 app.use('/highscore', highscoreRoutes);
+app.use('/server', serverRoutes);
 
 // in testing, we don't want to cache the results
 app.set('etag', false);
@@ -31,6 +34,10 @@ app.use((req, res, next) => {
   next();
 });
 
+setInterval(() => {
+  disposeInactiveGames();
+}, 60 * 1000);
+
 app.listen(port, () => {
   welcome();
   if (process.env.NODE_ENV === 'production') {

backend/src/interfaces/IGame.ts

@@ -12,6 +12,7 @@ export interface IGame {
   gameStatus: boolean;
   gameId: string;
   terrain: ITerrain;
+  lastActionTimeStamp: number;
 
   notifyUsers(): void;
 
@@ -37,4 +38,5 @@ export interface IGame {
   getUsers(): [User, IStats][];
 
   getTerrain(): ITerrain;
+  getLastActionTimeStamp(): number;
 }

backend/src/models/Game.ts

@@ -17,12 +17,14 @@ export class Game implements IGame {
   gameId: string;
   terrain: ITerrain;
   users: [User, IStats][]; // left [0] and right [1] user
+  lastActionTimeStamp: number;
 
   constructor(lobby: ILobby) {
     this.lobby = lobby;
     this.gameStatus = false; // game not finished
     this.gameId = Math.random().toString(36);
     this.terrain = new Terrain();
+    this.lastActionTimeStamp = Date.now();
 
     // insert the lobby users into the game and create a new stats object for each user
     this.users = lobby.getUsers().map((user) => [user, new Stats()]);
@@ -46,6 +48,9 @@ export class Game implements IGame {
     this.notifyUsers(); // TODO: implement this method
     log('Game ' + this.gameId + ' created.');
   }
+  getLastActionTimeStamp(): number {
+    return this.lastActionTimeStamp;
+  }
   getTerrain(): ITerrain {
     return this.terrain;
   }
@@ -173,6 +178,7 @@ export class Game implements IGame {
   setGameState(gameState: IGame): void {
     this.gameStatus = gameState.gameStatus;
     this.users = gameState.users;
+    this.lastActionTimeStamp = Date.now();
   }
 
   getGameState(): IGame {

backend/src/routes/serverRoutes.ts

+import express from 'express';
+import * as serverController from '../controllers/serverController';
+
+const router = express.Router();
+
+router.get('/heartbeat', serverController.heartbeat);
+
+export default router;