Merge branch 'main' of https://github.com/ets-cfuhrman-pfe/EvalueTonSavoir into feature/qr-code-url-generation

client/src/pages/Student/JoinRoom/JoinRoom.tsx

@@ -51,9 +51,8 @@ const JoinRoom: React.FC = () => {
     }, []);
 
     useEffect(() => {
-        // init the answers array, one for each question
-        setAnswers(Array(questions.length).fill({} as AnswerSubmissionToBackendType));
         console.log(`JoinRoom: useEffect: questions: ${JSON.stringify(questions)}`);
+        setAnswers(questions ? Array(questions.length).fill({} as AnswerSubmissionToBackendType) : []);
     }, [questions]);
     
 
@@ -76,6 +75,7 @@ const JoinRoom: React.FC = () => {
             console.log('on(launch-teacher-mode): Received launch-teacher-mode:', questions);
             setQuizMode('teacher');
             setIsWaitingForTeacher(true);
+            setQuestions([]);  // clear out from last time (in case quiz is repeated)
             setQuestions(questions);
             // wait for next-question
         });
@@ -84,6 +84,7 @@ const JoinRoom: React.FC = () => {
 
             setQuizMode('student');
             setIsWaitingForTeacher(false);
+            setQuestions([]);  // clear out from last time (in case quiz is repeated)
             setQuestions(questions);
             setQuestion(questions[0]);
         });

client/src/pages/Teacher/ManageRoom/ManageRoom.tsx

@@ -45,11 +45,43 @@ const ManageRoom: React.FC = () => {
     const [quizMode, setQuizMode] = useState<'teacher' | 'student'>('teacher');
     const [connectingError, setConnectingError] = useState<string>('');
     const [currentQuestion, setCurrentQuestion] = useState<QuestionType | undefined>(undefined);
-    const [quizStarted, setQuizStarted] = useState(false);
-    const [formattedRoomName, setFormattedRoomName] = useState("");
+    const [quizStarted, setQuizStarted] = useState<boolean>(false);
+    const [formattedRoomName, setFormattedRoomName] = useState('');
+    const [newlyConnectedUser, setNewlyConnectedUser] = useState<StudentType | null>(null);
     const roomUrl = `${window.location.origin}/student/join-room?roomName=${roomName}`;
     const [showQrModal, setShowQrModal] = useState(false);
 
+    // Handle the newly connected user in useEffect, because it needs state info
+    // not available in the socket.on() callback
+    useEffect(() => {
+        if (newlyConnectedUser) {
+            console.log(`Handling newly connected user: ${newlyConnectedUser.name}`);
+            setStudents((prevStudents) => [...prevStudents, newlyConnectedUser]);
+
+            // only send nextQuestion if the quiz has started
+            if (!quizStarted) {
+                console.log(`!quizStarted: returning.... `);
+                return;
+            }
+
+            if (quizMode === 'teacher') {
+                webSocketService.nextQuestion({
+                    roomName: formattedRoomName,
+                    questions: quizQuestions,
+                    questionIndex: Number(currentQuestion?.question.id) - 1,
+                    isLaunch: true // started late
+                });
+            } else if (quizMode === 'student') {
+                webSocketService.launchStudentModeQuiz(formattedRoomName, quizQuestions);
+            } else {
+                console.error('Invalid quiz mode:', quizMode);
+            }
+
+            // Reset the newly connected user state
+            setNewlyConnectedUser(null);
+        }
+    }, [newlyConnectedUser]);
+
     useEffect(() => {
         const verifyLogin = async () => {
             if (!ApiService.isLoggedIn()) {
@@ -61,6 +93,15 @@ const ManageRoom: React.FC = () => {
         verifyLogin();
     }, []);
 
+    useEffect(() => {
+        if (!roomName) {
+            console.error('Room name is missing!');
+            return;
+        }
+
+        console.log(`Joining room: ${roomName}`);
+    }, [roomName]);
+
     useEffect(() => {
         if (!roomName || !quizId) {
             window.alert(
@@ -77,15 +118,6 @@ const ManageRoom: React.FC = () => {
         };
     }, [roomName, navigate]);
 
-    useEffect(() => {
-        if (!roomName) {
-            console.error('Room name is missing!');
-            return;
-        }
-
-        console.log(`Joining room: ${roomName}`);
-    }, [roomName]);
-
     useEffect(() => {
         if (quizId) {
             const fetchQuiz = async () => {
@@ -130,6 +162,17 @@ const ManageRoom: React.FC = () => {
         const roomNameUpper = roomName.toUpperCase();
         setFormattedRoomName(roomNameUpper);
         console.log(`Creating WebSocket room named ${roomNameUpper}`);
+
+        /**
+         * ATTENTION: Lire les variables d'état dans
+         * les .on() n'est pas une bonne pratique.
+         * Les valeurs sont celles au moment de la création
+         * de la fonction et non au moment de l'exécution.
+         * Il faut utiliser des refs pour les valeurs qui
+         * changent fréquemment. Sinon, utiliser un trigger
+         * de useEffect pour mettre déclencher un traitement
+         * (voir user-joined plus bas).
+         */
         socket.on('connect', () => {
             webSocketService.createRoom(roomNameUpper);
         });
@@ -144,23 +187,9 @@ const ManageRoom: React.FC = () => {
         });
 
         socket.on('user-joined', (student: StudentType) => {
-            console.log(`Student joined: name = ${student.name}, id = ${student.id}, quizMode = ${quizMode}, quizStarted = ${quizStarted}`);
-
-            setStudents((prevStudents) => [...prevStudents, student]);
-
-            // only send nextQuestion if the quiz has started
-            if (!quizStarted) return;
-
-            if (quizMode === 'teacher') {
-                webSocketService.nextQuestion(
-                    {roomName: formattedRoomName, 
-                    questions: quizQuestions,
-                    questionIndex: Number(currentQuestion?.question.id) - 1,
-                     isLaunch: false});
-            } else if (quizMode === 'student') {
-                webSocketService.launchStudentModeQuiz(formattedRoomName, quizQuestions);
-            }
+            setNewlyConnectedUser(student);
         });
+
         socket.on('join-failure', (message) => {
             setConnectingError(message);
             setSocket(null);
@@ -175,7 +204,6 @@ const ManageRoom: React.FC = () => {
     };
 
     useEffect(() => {
-
         if (socket) {
             console.log(`Listening for submit-answer-room in room ${formattedRoomName}`);
             socket.on('submit-answer-room', (answerData: AnswerReceptionFromBackendType) => {
@@ -249,10 +277,12 @@ const ManageRoom: React.FC = () => {
         if (nextQuestionIndex === undefined || nextQuestionIndex > quizQuestions.length - 1) return;
 
         setCurrentQuestion(quizQuestions[nextQuestionIndex]);
-        webSocketService.nextQuestion({roomName: formattedRoomName, 
+        webSocketService.nextQuestion({
+            roomName: formattedRoomName,
             questions: quizQuestions,
             questionIndex: nextQuestionIndex,
-                                       isLaunch: false});
+            isLaunch: false
+        });
     };
 
     const previousQuestion = () => {
@@ -295,7 +325,12 @@ const ManageRoom: React.FC = () => {
         }
 
         setCurrentQuestion(quizQuestions[0]);
-        webSocketService.nextQuestion({roomName: formattedRoomName, questions: quizQuestions, questionIndex: 0, isLaunch: true});
+        webSocketService.nextQuestion({
+            roomName: formattedRoomName,
+            questions: quizQuestions,
+            questionIndex: 0,
+            isLaunch: true
+        });
     };
 
     const launchStudentMode = () => {
@@ -311,21 +346,19 @@ const ManageRoom: React.FC = () => {
     };
 
     const launchQuiz = () => {
+        setQuizStarted(true);
         if (!socket || !formattedRoomName || !quiz?.content || quiz?.content.length === 0) {
             // TODO: This error happens when token expires! Need to handle it properly
             console.log(
                 `Error launching quiz. socket: ${socket}, roomName: ${formattedRoomName}, quiz: ${quiz}`
             );
-            setQuizStarted(true);
-
             return;
         }
+        console.log(`Launching quiz in ${quizMode} mode...`);
         switch (quizMode) {
             case 'student':
-                setQuizStarted(true);
                 return launchStudentMode();
             case 'teacher':
-                setQuizStarted(true);
                 return launchTeacherMode();
         }
     };
@@ -334,7 +367,12 @@ const ManageRoom: React.FC = () => {
         if (quiz?.content && quizQuestions) {
             setCurrentQuestion(quizQuestions[questionIndex]);
             if (quizMode === 'teacher') {
-                webSocketService.nextQuestion({roomName: formattedRoomName, questions: quizQuestions, questionIndex, isLaunch: false});
+                webSocketService.nextQuestion({
+                    roomName: formattedRoomName,
+                    questions: quizQuestions,
+                    questionIndex,
+                    isLaunch: false
+                });
             }
         }
     };
@@ -473,7 +511,6 @@ const ManageRoom: React.FC = () => {
                     </Button>
                 </DialogActions>
             </Dialog>
-
             <div className="roomHeader">
                 <DisconnectButton
                     onReturn={handleReturn}
@@ -533,7 +570,6 @@ const ManageRoom: React.FC = () => {
                                     <QuestionDisplay
                                         showAnswer={false}
                                         question={currentQuestion?.question as Question}
-                                        
                                     />
                                 )}
 

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();

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;