live updates

backend/package.json

@@ -15,6 +15,7 @@
     "dotenv": "^16.4.5",
     "cors": "^2.8.5",
     "node-fetch": "^3.3.2",
-    "express-rate-limit": "^7.1.5"
+    "express-rate-limit": "^7.1.5",
+    "socket.io": "^4.6.1"
   }
 }

backend/src/index.js

@@ -4,10 +4,12 @@ import dotenv from 'dotenv';
 import path from 'path';
 import fs from 'fs';
 import { fileURLToPath } from 'url';
+import { createServer } from 'http';
 import rateLimit from 'express-rate-limit';
 import { initDB } from './db/index.js';
 import { validateConfig, config } from './config.js';
 import { errorHandler } from './middleware/errorHandler.js';
+import { initializeSocket } from './sockets/index.js';
 import authRoutes from './routes/auth.js';
 import challengeRoutes from './routes/challenges.js';
 import predictionRoutes from './routes/predictions.js';
@@ -24,6 +26,10 @@ const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
 
 const app = express();
+const httpServer = createServer(app);
+
+// Initialize Socket.io
+initializeSocket(httpServer);
 
 // Rate limiting
 const authLimiter = rateLimit({
@@ -96,8 +102,9 @@ const PORT = config.server.port;
 // Initialize database and start server
 initDB()
   .then(() => {
-    app.listen(PORT, '0.0.0.0', () => {
+    httpServer.listen(PORT, '0.0.0.0', () => {
       console.log(`✅ Server running on port ${PORT}`);
+      console.log(`🔌 Socket.io ready for real-time updates`);
     });
   })
   .catch(err => {

backend/src/routes/challenges.js

@@ -2,6 +2,7 @@ import express from 'express';
 import { query } from '../db/index.js';
 import { authMiddleware } from '../middleware/auth.js';
 import { asyncHandler, AppError } from '../middleware/errorHandler.js';
+import { socketEvents } from '../sockets/index.js';
 
 const router = express.Router();
 
@@ -147,46 +148,49 @@ router.post('/:id/invite', authMiddleware, asyncHandler(async (req, res) => {
             [challengeId, userId]
           );
           invitedUsers.push(userId);
+        
+        // Emit real-time notification to invited user
+        socketEvents.challengeInvitation(userId, {
+          challenge_id: challengeId,
+          challenge_title: challenge.title,
+          invited_by: req.user.username
+        });
+      } catch (err) {
+        // Ignore duplicate key errors
+      }
+    }
+  }
+
+  // Invite by emails
+  if (emails && Array.isArray(emails)) {
+    for (const email of emails) {
+      const users = await query('SELECT id FROM users WHERE email = ?', [email]);
+      if (users.length > 0) {
+        try {
+          await query(
+            'INSERT INTO challenge_participants (challenge_id, user_id, status) VALUES (?, ?, "pending")',
+            [challengeId, users[0].id]
+          );
+          invitedUsers.push(users[0].id);
+          
+          // Emit real-time notification to invited user
+          socketEvents.challengeInvitation(users[0].id, {
+            challenge_id: challengeId,
+            challenge_title: challenge.title,
+            invited_by: req.user.username
+          });
         } catch (err) {
           // Ignore duplicate key errors
         }
       }
     }
-
-    // Invite by emails
-    if (emails && Array.isArray(emails)) {
-      for (const email of emails) {
-        const users = await query('SELECT id FROM users WHERE email = ?', [email]);
-        if (users.length > 0) {
-          try {
-            await query(
-              'INSERT INTO challenge_participants (challenge_id, user_id, status) VALUES (?, ?, "pending")',
-              [challengeId, users[0].id]
-            );
-            invitedUsers.push(users[0].id);
-          } catch (err) {
-            // Ignore duplicate key errors
-          }
-        }
-      }
-    }
-
-  res.json({ invited: invitedUsers.length });
-}));
-
-// Accept/reject challenge invitation
-router.post('/:id/respond', authMiddleware, asyncHandler(async (req, res) => {
-  const challengeId = req.params.id;
-  const { status } = req.body; // 'accepted' or 'rejected'
-
-  if (!['accepted', 'rejected'].includes(status)) {
-    throw new AppError('Invalid status', 400);
   }
-
-  await query(
-    'UPDATE challenge_participants SET status = ?, responded_at = NOW() WHERE challenge_id = ? AND user_id = ?',
-    [status, challengeId, req.user.userId]
-  );
+  // Emit real-time event to challenge participants
+  socketEvents.challengeInvitationResponse(challengeId, {
+    user_id: req.user.userId,
+    username: req.user.username,
+    status
+  });
 
   res.json({ status });
 }));

backend/src/routes/friends.js

@@ -2,6 +2,7 @@ import express from 'express';
 import { query } from '../db/index.js';
 import { authMiddleware } from '../middleware/auth.js';
 import { asyncHandler, AppError } from '../middleware/errorHandler.js';
+import { socketEvents } from '../sockets/index.js';
 
 const router = express.Router();
 
@@ -99,6 +100,12 @@ router.post('/request', authMiddleware, asyncHandler(async (req, res) => {
     [req.user.userId, user_id]
   );
 
+  // Emit real-time notification to the user receiving the friend request
+  socketEvents.friendRequest(user_id, {
+    from_user_id: req.user.userId,
+    from_username: req.user.username
+  });
+
   res.json({ success: true });
 }));
 
@@ -125,6 +132,16 @@ router.post('/respond', authMiddleware, asyncHandler(async (req, res) => {
     [status, friendship_id]
   );
 
+  // Get the friendship to notify the requester
+  const friendship = friendships[0];
+  
+  // Emit real-time notification to the user who sent the request
+  socketEvents.friendRequestResponse(friendship.user_id, {
+    friend_id: req.user.userId,
+    friend_username: req.user.username,
+    status
+  });
+
   res.json({ status });
 }));
 

backend/src/routes/predictions.js

@@ -2,6 +2,7 @@ import express from 'express';
 import { query } from '../db/index.js';
 import { authMiddleware } from '../middleware/auth.js';
 import { asyncHandler, AppError } from '../middleware/errorHandler.js';
+import { socketEvents } from '../sockets/index.js';
 
 const router = express.Router();
 
@@ -73,6 +74,9 @@ router.post('/', authMiddleware, asyncHandler(async (req, res) => {
     created_at: new Date()
   };
 
+  // Emit real-time event to all users in the challenge
+  socketEvents.predictionCreated(challenge_id, prediction);
+
   res.json({ prediction });
 }));
 
@@ -120,6 +124,19 @@ router.post('/:id/validate', authMiddleware, asyncHandler(async (req, res) => {
     [status, req.user.userId, predictionId]
   );
 
+  // Get updated prediction with usernames
+  const updatedPrediction = await query(
+    `SELECT p.*, u.username, v.username as validated_by_username
+     FROM predictions p
+     INNER JOIN users u ON p.user_id = u.id
+     LEFT JOIN users v ON p.validated_by = v.id
+     WHERE p.id = ?`,
+    [predictionId]
+  );
+
+  // Emit real-time event to all users in the challenge
+  socketEvents.predictionValidated(prediction.challenge_id, updatedPrediction[0]);
+
   res.json({ status });
 }));
 

backend/src/sockets/index.js

@@ -0,0 +1,111 @@
+/**
+ * Socket.io setup and event handlers
+ */
+import { Server } from 'socket.io';
+import jwt from 'jsonwebtoken';
+
+let io;
+
+export function initializeSocket(server) {
+  io = new Server(server, {
+    cors: {
+      origin: process.env.CORS_ORIGIN || '*',
+      credentials: true
+    }
+  });
+
+  // Authentication middleware for socket connections
+  io.use((socket, next) => {
+    try {
+      const token = socket.handshake.auth.token;
+      
+      if (!token) {
+        return next(new Error('Authentication error: No token provided'));
+      }
+
+      const decoded = jwt.verify(token, process.env.JWT_SECRET);
+      socket.userId = decoded.userId;
+      socket.username = decoded.username;
+      next();
+    } catch (err) {
+      next(new Error('Authentication error: Invalid token'));
+    }
+  });
+
+  io.on('connection', (socket) => {
+    console.log(`✅ Socket connected: ${socket.username} (${socket.userId})`);
+    
+    // Join personal room for user-specific notifications
+    socket.join(`user:${socket.userId}`);
+
+    // Handle joining challenge rooms
+    socket.on('join:challenge', (challengeId) => {
+      socket.join(`challenge:${challengeId}`);
+      console.log(`👥 ${socket.username} joined challenge:${challengeId}`);
+    });
+
+    // Handle leaving challenge rooms
+    socket.on('leave:challenge', (challengeId) => {
+      socket.leave(`challenge:${challengeId}`);
+      console.log(`👋 ${socket.username} left challenge:${challengeId}`);
+    });
+
+    socket.on('disconnect', () => {
+      console.log(`❌ Socket disconnected: ${socket.username}`);
+    });
+  });
+
+  return io;
+}
+
+export function getIO() {
+  if (!io) {
+    throw new Error('Socket.io not initialized');
+  }
+  return io;
+}
+
+// Event emitters for different actions
+export const socketEvents = {
+  // Emit to specific user
+  emitToUser(userId, event, data) {
+    io.to(`user:${userId}`).emit(event, data);
+  },
+
+  // Emit to all users in a challenge
+  emitToChallenge(challengeId, event, data) {
+    io.to(`challenge:${challengeId}`).emit(event, data);
+  },
+
+  // Prediction events
+  predictionCreated(challengeId, prediction) {
+    this.emitToChallenge(challengeId, 'prediction:created', prediction);
+  },
+
+  predictionValidated(challengeId, prediction) {
+    this.emitToChallenge(challengeId, 'prediction:validated', prediction);
+  },
+
+  // Challenge events
+  challengeInvitation(userId, challenge) {
+    this.emitToUser(userId, 'challenge:invitation', challenge);
+  },
+
+  challengeInvitationResponse(challengeId, response) {
+    this.emitToChallenge(challengeId, 'challenge:invitation_response', response);
+  },
+
+  // Friend events
+  friendRequest(userId, request) {
+    this.emitToUser(userId, 'friend:request', request);
+  },
+
+  friendRequestResponse(userId, response) {
+    this.emitToUser(userId, 'friend:response', response);
+  },
+
+  // Leaderboard updates
+  leaderboardUpdate(challengeId, leaderboard) {
+    this.emitToChallenge(challengeId, 'leaderboard:update', leaderboard);
+  }
+};

frontend/package.json

@@ -11,7 +11,8 @@
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-router-dom": "^6.20.0",
-    "react-hot-toast": "^2.4.1"
+    "react-hot-toast": "^2.4.1",
+    "socket.io-client": "^4.6.1"
   },
   "devDependencies": {
     "@vitejs/plugin-react": "^4.2.1",

frontend/src/SocketContext.jsx

@@ -0,0 +1,91 @@
+import React, { createContext, useContext, useEffect, useState } from 'react';
+import { io } from 'socket.io-client';
+import { useAuth } from './AuthContext';
+
+const SocketContext = createContext();
+
+export function useSocket() {
+  const context = useContext(SocketContext);
+  if (!context) {
+    throw new Error('useSocket must be used within SocketProvider');
+  }
+  return context;
+}
+
+export function SocketProvider({ children }) {
+  const [socket, setSocket] = useState(null);
+  const [connected, setConnected] = useState(false);
+  const { user, token } = useAuth();
+
+  useEffect(() => {
+    // Only connect if user is authenticated
+    if (!user || !token) {
+      if (socket) {
+        socket.disconnect();
+        setSocket(null);
+        setConnected(false);
+      }
+      return;
+    }
+
+    // Determine backend URL
+    const backendUrl = import.meta.env.VITE_API_URL || 
+      (import.meta.env.DEV ? 'http://localhost:4000' : window.location.origin);
+
+    // Create socket connection with JWT authentication
+    const newSocket = io(backendUrl, {
+      auth: {
+        token
+      },
+      reconnection: true,
+      reconnectionAttempts: 5,
+      reconnectionDelay: 1000
+    });
+
+    newSocket.on('connect', () => {
+      console.log('🔌 Socket connected');
+      setConnected(true);
+    });
+
+    newSocket.on('disconnect', () => {
+      console.log('❌ Socket disconnected');
+      setConnected(false);
+    });
+
+    newSocket.on('connect_error', (error) => {
+      console.error('Socket connection error:', error.message);
+    });
+
+    setSocket(newSocket);
+
+    // Cleanup on unmount
+    return () => {
+      newSocket.disconnect();
+    };
+  }, [user, token]);
+
+  const joinChallenge = (challengeId) => {
+    if (socket && connected) {
+      socket.emit('join:challenge', challengeId);
+    }
+  };
+
+  const leaveChallenge = (challengeId) => {
+    if (socket && connected) {
+      socket.emit('leave:challenge', challengeId);
+    }
+  };
+
+  const value = {
+    socket,
+    connected,
+    joinChallenge,
+    leaveChallenge
+  };
+
+  return (
+    <SocketContext.Provider value={value}>
+      {children}
+    </SocketContext.Provider>
+  );
+}

frontend/src/main.jsx

@@ -3,6 +3,7 @@ import ReactDOM from 'react-dom/client';
 import { BrowserRouter, Routes, Route, Navigate, Link } from 'react-router-dom';
 import { Toaster } from 'react-hot-toast';
 import { AuthProvider, useAuth } from './AuthContext';
+import { SocketProvider } from './SocketContext';
 import Login from './pages/Login';
 import Register from './pages/Register';
 import ChallengeList from './pages/ChallengeList';
@@ -55,40 +56,42 @@ function App() {
     <ErrorBoundary>
       <BrowserRouter>
         <AuthProvider>
-          <Toaster 
-            position="top-right"
-            toastOptions={{
-              duration: 3000,
-              style: {
-                background: '#1e293b',
-                color: '#f1f5f9',
-                border: '1px solid #334155',
-              },
-              success: {
-                iconTheme: {
-                  primary: '#10b981',
-                  secondary: '#f1f5f9',
+          <SocketProvider>
+            <Toaster 
+              position="top-right"
+              toastOptions={{
+                duration: 3000,
+                style: {
+                  background: '#1e293b',
+                  color: '#f1f5f9',
+                  border: '1px solid #334155',
                 },
-              },
-              error: {
-                iconTheme: {
-                  primary: '#ef4444',
-                  secondary: '#f1f5f9',
+                success: {
+                  iconTheme: {
+                    primary: '#10b981',
+                    secondary: '#f1f5f9',
+                  },
                 },
-              },
-            }}
-          />
-          <Header />
-          <Routes>
-            <Route path="/login" element={<Login />} />
-            <Route path="/register" element={<Register />} />
-            <Route path="/challenges" element={<ProtectedRoute><ChallengeList /></ProtectedRoute>} />
-            <Route path="/challenges/:id" element={<ProtectedRoute><ChallengeDetail /></ProtectedRoute>} />
-            <Route path="/profile" element={<ProtectedRoute><Profile /></ProtectedRoute>} />
-            <Route path="/friends" element={<ProtectedRoute><Friends /></ProtectedRoute>} />
-            <Route path="/leaderboard" element={<ProtectedRoute><Leaderboard /></ProtectedRoute>} />
-            <Route path="/" element={<Navigate to="/challenges" />} />
-          </Routes>
+                error: {
+                  iconTheme: {
+                    primary: '#ef4444',
+                    secondary: '#f1f5f9',
+                  },
+                },
+              }}
+            />
+            <Header />
+            <Routes>
+              <Route path="/login" element={<Login />} />
+              <Route path="/register" element={<Register />} />
+              <Route path="/challenges" element={<ProtectedRoute><ChallengeList /></ProtectedRoute>} />
+              <Route path="/challenges/:id" element={<ProtectedRoute><ChallengeDetail /></ProtectedRoute>} />
+              <Route path="/profile" element={<ProtectedRoute><Profile /></ProtectedRoute>} />
+              <Route path="/friends" element={<ProtectedRoute><Friends /></ProtectedRoute>} />
+              <Route path="/leaderboard" element={<ProtectedRoute><Leaderboard /></ProtectedRoute>} />
+              <Route path="/" element={<Navigate to="/challenges" />} />
+            </Routes>
+          </SocketProvider>
         </AuthProvider>
       </BrowserRouter>
     </ErrorBoundary>

frontend/src/pages/ChallengeDetail.jsx

@@ -2,12 +2,14 @@ import React, { useState, useEffect, useRef } from 'react';
 import { useParams, Link } from 'react-router-dom';
 import toast from 'react-hot-toast';
 import { useAuth } from '../AuthContext';
+import { useSocket } from '../SocketContext';
 import api from '../api';
 import { useClickOutside } from '../hooks/useClickOutside';
 
 export default function ChallengeDetail() {
   const { id } = useParams();
   const { user } = useAuth();
+  const { socket, joinChallenge, leaveChallenge } = useSocket();
   const [challenge, setChallenge] = useState(null);
   const [predictions, setPredictions] = useState([]);
   const [leaderboard, setLeaderboard] = useState([]);
@@ -29,6 +31,59 @@ export default function ChallengeDetail() {
     loadLeaderboard();
   }, [id]);
 
+  // Join challenge room for real-time updates
+  useEffect(() => {
+    if (socket && id) {
+      joinChallenge(id);
+      
+      return () => {
+        leaveChallenge(id);
+      };
+    }
+  }, [socket, id]);
+
+  // Listen for real-time prediction events
+  useEffect(() => {
+    if (!socket) return;
+
+    const handlePredictionCreated = (prediction) => {
+      setPredictions(prev => [prediction, ...prev]);
+      toast.success(`New prediction from ${prediction.username}`);
+    };
+
+    const handlePredictionValidated = (prediction) => {
+      setPredictions(prev => 
+        prev.map(p => p.id === prediction.id ? prediction : p)
+      );
+      loadLeaderboard(); // Refresh leaderboard when points change
+      
+      if (prediction.user_id === user.id) {
+        toast.success(
+          prediction.status === 'validated' 
+            ? '🎉 Your prediction was validated!' 
+            : '❌ Your prediction was invalidated'
+        );
+      }
+    };
+
+    const handleInvitationResponse = (response) => {
+      if (response.status === 'accepted') {
+        toast.success(`${response.username} joined the challenge!`);
+        loadChallenge(); // Refresh participant list
+      }
+    };
+
+    socket.on('prediction:created', handlePredictionCreated);
+    socket.on('prediction:validated', handlePredictionValidated);
+    socket.on('challenge:invitation_response', handleInvitationResponse);
+
+    return () => {
+      socket.off('prediction:created', handlePredictionCreated);
+      socket.off('prediction:validated', handlePredictionValidated);
+      socket.off('challenge:invitation_response', handleInvitationResponse);
+    };
+  }, [socket, user]);
+
   const loadChallenge = async () => {
     try {
       const data = await api.getChallenge(id);

frontend/src/pages/ChallengeList.jsx

@@ -3,6 +3,7 @@ import { Link } from 'react-router-dom';
 import toast from 'react-hot-toast';
 import api from '../api';
 import { useClickOutside } from '../hooks/useClickOutside';
+import { useSocket } from '../SocketContext';
 
 export default function ChallengeList() {
   const [challenges, setChallenges] = useState([]);
@@ -13,6 +14,7 @@ export default function ChallengeList() {
   const [creating, setCreating] = useState(false);
   const [searchTimeout, setSearchTimeout] = useState(null);
   const [respondingTo, setRespondingTo] = useState(null);
+  const { socket } = useSocket();
   const searchRef = useRef(null);
 
   useClickOutside(searchRef, () => setShowResults([]));
@@ -21,6 +23,22 @@ export default function ChallengeList() {
     loadChallenges();
   }, []);
 
+  // Listen for real-time challenge invitations
+  useEffect(() => {
+    if (!socket) return;
+
+    const handleChallengeInvitation = (invitation) => {
+      toast.success(`📬 ${invitation.invited_by} invited you to "${invitation.challenge_title}"`);
+      loadChallenges(); // Refresh to show new invitation
+    };
+
+    socket.on('challenge:invitation', handleChallengeInvitation);
+
+    return () => {
+      socket.off('challenge:invitation', handleChallengeInvitation);
+    };
+  }, [socket]);
+
   const loadChallenges = async () => {
     try {
       const data = await api.getChallenges();

frontend/src/pages/Friends.jsx

@@ -2,6 +2,7 @@ import React, { useState, useEffect, useRef } from 'react';
 import toast from 'react-hot-toast';
 import api from '../api';
 import { useClickOutside } from '../hooks/useClickOutside';
+import { useSocket } from '../SocketContext';
 
 export default function Friends() {
   const [friends, setFriends] = useState([]);
@@ -13,6 +14,7 @@ export default function Friends() {
   const [searchTimeout, setSearchTimeout] = useState(null);
   const [responding, setResponding] = useState(null);
   const [sending, setSending] = useState(null);
+  const { socket } = useSocket();
   const searchRef = useRef(null);
 
   useClickOutside(searchRef, () => setSearchResults([]));
@@ -21,6 +23,33 @@ export default function Friends() {
     loadData();
   }, []);
 
+  // Listen for real-time friend request events
+  useEffect(() => {
+    if (!socket) return;
+
+    const handleFriendRequest = (request) => {
+      toast.success(`👋 ${request.from_username} sent you a friend request`);
+      loadData(); // Refresh to show new request
+    };
+
+    const handleFriendResponse = (response) => {
+      if (response.status === 'accepted') {
+        toast.success(`🎉 ${response.friend_username} accepted your friend request!`);
+        loadData(); // Refresh friends list
+      } else {
+        toast(`${response.friend_username} declined your friend request`);
+      }
+    };
+
+    socket.on('friend:request', handleFriendRequest);
+    socket.on('friend:response', handleFriendResponse);
+
+    return () => {
+      socket.off('friend:request', handleFriendRequest);
+      socket.off('friend:response', handleFriendResponse);
+    };
+  }, [socket]);
+
   const loadData = async () => {
     try {
       const [friendsData, requestsData] = await Promise.all([