From 09b7759c8e5197c6b1fdc45cdcc7ac1a2ac987f3 Mon Sep 17 00:00:00 2001
From: Kislay <kislayudbhav.verma.cd.eee22@itbhu.ac.in>
Date: Sat, 1 Jun 2024 13:39:04 +0530
Subject: [PATCH] api: Implement server side of long polling.

This commit adds a handler for GET /events which
stores the response object for the client for emitting
events in the future.
---
 backend/eventRecipients.ts   | 18 ++++++++++++++++++
 backend/routes/gameRoutes.js | 10 ++++++++++
 2 files changed, 28 insertions(+)
 create mode 100644 backend/eventRecipients.ts

diff --git a/backend/eventRecipients.ts b/backend/eventRecipients.ts
new file mode 100644
index 0000000..3861c85
--- /dev/null
+++ b/backend/eventRecipients.ts
@@ -0,0 +1,18 @@
+// this module is responsible for handling the clients currently connected to the server.
+// It stores the clients in a Map object, where the key is the client's user_id and the value is the client's http response object.
+
+import { Response } from 'express';
+
+const clients = new Map<string, Response>();
+
+export function addClient(userId: string, res: Response) {
+    clients.set(userId, res);
+}
+
+export function removeClient(userId: string) {
+    clients.delete(userId);
+}
+
+export function getClient(userId: string) {
+    return clients.get(userId);
+}
diff --git a/backend/routes/gameRoutes.js b/backend/routes/gameRoutes.js
index e69de29..fa43827 100644
--- a/backend/routes/gameRoutes.js
+++ b/backend/routes/gameRoutes.js
@@ -0,0 +1,10 @@
+import express from 'express';
+import { addClient } from '../eventRecipients';
+const router = express.Router();
+
+router.get('/events', (req, res) => {
+    addClient('user_id', res);
+});
+
+// the post handler should retrieve the game the user is currently in, and update the game state.
+// The request body contains the event data, as described in ARCHITECTURE.md