From dcaee719d17f9f67d8447440fae0683320f10668 Mon Sep 17 00:00:00 2001
From: "C. Fuhrman" <christopher.fuhrman@etsmtl.ca>
Date: Mon, 10 Mar 2025 15:20:07 -0400
Subject: [PATCH] =?UTF-8?q?Fixes=20#286=20-=20Faire=20un=20vrai=20singleto?=
 =?UTF-8?q?n=20pour=20la=20connexion=20=C3=A0=20la=20base=20de=20donn?=
 =?UTF-8?q?=C3=A9es?=
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---
 server/app.js       |  7 +++++++
 server/config/db.js | 39 ++++++++++++++++++++++++++++++++-------
 2 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/server/app.js b/server/app.js
index 32f64b9..938d2f0 100644
--- a/server/app.js
+++ b/server/app.js
@@ -127,4 +127,11 @@ async function start() {
   });
 }
 
+// Graceful shutdown on SIGINT (Ctrl+C)
+process.on('SIGINT', async () => {
+  console.log('Shutting down...');
+  await db.closeConnection();
+  process.exit(0);
+});
+
 start();
diff --git a/server/config/db.js b/server/config/db.js
index cf492bf..ccc43e7 100644
--- a/server/config/db.js
+++ b/server/config/db.js
@@ -1,28 +1,53 @@
 const { MongoClient } = require('mongodb');
-const dotenv = require('dotenv')
+const dotenv = require('dotenv');
 
 dotenv.config();
 
 class DBConnection {
-
     constructor() {
         this.mongoURI = process.env.MONGO_URI;
         this.databaseName = process.env.MONGO_DATABASE;
+        this.client = null;
         this.connection = null;
     }
 
+    // Connect to the database, but don't reconnect if already connected
     async connect() {
-        const client = new MongoClient(this.mongoURI);
-        this.connection = await client.connect();
+        if (this.connection) {
+            console.log('Using existing MongoDB connection');
+            return this.connection;
+        }
+
+        try {
+            // Create the MongoClient only if the connection does not exist
+            this.client = new MongoClient(this.mongoURI);
+            await this.client.connect();
+            this.connection = this.client.db(this.databaseName);
+            console.log('MongoDB connected');
+            return this.connection;
+        } catch (error) {
+            console.error('MongoDB connection error:', error);
+            throw new Error('Failed to connect to MongoDB');
+        }
     }
 
+    // Return the current database connection
     getConnection() {
         if (!this.connection) {
-            throw new Error('Connexion MongoDB non établie');
+            throw new Error('MongoDB connection not established');
+        }
+        return this.connection;
+    }
+
+    // Close the MongoDB connection gracefully
+    async closeConnection() {
+        if (this.client) {
+            await this.client.close();
+            console.log('MongoDB connection closed');
         }
-        return this.connection.db(this.databaseName);
     }
 }
 
+// Exporting the singleton instance
 const instance = new DBConnection();
-module.exports = instance;
\ No newline at end of file
+module.exports = instance;