feat: add chat message history and infinite scroll

Backend changes:
- Socket.IO: Send last 20 messages on join_event_room
- REST API: Add GET /api/events/:eventId/messages endpoint with pagination
- Support for 'before' cursor-based pagination for loading older messages

Frontend changes:
- Load initial 20 messages when joining event chat
- Implement infinite scroll to load older messages on scroll to top
- Add loading indicator for older messages
- Preserve scroll position when loading older messages
- Add eventsAPI.getMessages() function for pagination

User experience:
- New users see last 20 messages immediately
- Scrolling up automatically loads older messages in batches of 20
- Smooth scrolling experience with position restoration

Note: Messages are encrypted in transit via HTTPS/WSS but stored
as plain text in database (no E2E encryption).
This commit is contained in:
Radosław Gierwiało
2025-11-13 20:16:58 +01:00
parent 833818f17d
commit 9d8fc9f6d6
4 changed files with 178 additions and 3 deletions

View File

@@ -1,5 +1,6 @@
const express = require('express');
const { prisma } = require('../utils/db');
const { authenticate } = require('../middleware/auth');
const router = express.Router();
@@ -68,4 +69,66 @@ router.get('/:id', async (req, res, next) => {
}
});
// GET /api/events/:eventId/messages - Get event chat messages with pagination
router.get('/:eventId/messages', authenticate, async (req, res, next) => {
try {
const { eventId } = req.params;
const { before, limit = 20 } = req.query;
// Find event chat room
const chatRoom = await prisma.chatRoom.findFirst({
where: {
eventId: parseInt(eventId),
type: 'event',
},
});
if (!chatRoom) {
return res.status(404).json({
success: false,
error: 'Chat room not found',
});
}
// Build query with pagination
const where = { roomId: chatRoom.id };
if (before) {
where.id = { lt: parseInt(before) };
}
const messages = await prisma.message.findMany({
where,
include: {
user: {
select: {
id: true,
username: true,
avatar: true,
},
},
},
orderBy: { createdAt: 'desc' },
take: parseInt(limit),
});
// Return in chronological order (oldest first)
res.json({
success: true,
data: messages.reverse().map(msg => ({
id: msg.id,
roomId: msg.roomId,
userId: msg.user.id,
username: msg.user.username,
avatar: msg.user.avatar,
content: msg.content,
type: msg.type,
createdAt: msg.createdAt,
})),
hasMore: messages.length === parseInt(limit),
});
} catch (error) {
next(error);
}
});
module.exports = router;

View File

@@ -77,6 +77,43 @@ function initializeSocket(httpServer) {
console.log(`👤 ${socket.user.username} joined event room ${eventId}`);
// Load last 20 messages from database
const chatRoom = await prisma.chatRoom.findFirst({
where: {
eventId: parseInt(eventId),
type: 'event',
},
});
if (chatRoom) {
const messages = await prisma.message.findMany({
where: { roomId: chatRoom.id },
include: {
user: {
select: {
id: true,
username: true,
avatar: true,
},
},
},
orderBy: { createdAt: 'desc' },
take: 20,
});
// Send message history to the joining user (reverse to chronological order)
socket.emit('message_history', messages.reverse().map(msg => ({
id: msg.id,
roomId: msg.roomId,
userId: msg.user.id,
username: msg.user.username,
avatar: msg.user.avatar,
content: msg.content,
type: msg.type,
createdAt: msg.createdAt,
})));
}
// Broadcast updated active users list
const users = Array.from(activeUsers.get(eventId)).map(u => JSON.parse(u));
io.to(roomName).emit('active_users', users);

View File

@@ -3,8 +3,9 @@ import { useParams, useNavigate } from 'react-router-dom';
import Layout from '../components/layout/Layout';
import { useAuth } from '../contexts/AuthContext';
import { mockEvents } from '../mocks/events';
import { Send, UserPlus } from 'lucide-react';
import { Send, UserPlus, Loader2 } from 'lucide-react';
import { connectSocket, disconnectSocket, getSocket } from '../services/socket';
import { eventsAPI } from '../services/api';
const EventChatPage = () => {
const { eventId } = useParams();
@@ -14,7 +15,10 @@ const EventChatPage = () => {
const [newMessage, setNewMessage] = useState('');
const [activeUsers, setActiveUsers] = useState([]);
const [isConnected, setIsConnected] = useState(false);
const [loadingOlder, setLoadingOlder] = useState(false);
const [hasMore, setHasMore] = useState(true);
const messagesEndRef = useRef(null);
const messagesContainerRef = useRef(null);
const event = mockEvents.find(e => e.id === parseInt(eventId));
@@ -46,7 +50,13 @@ const EventChatPage = () => {
setIsConnected(false);
});
// Receive messages
// Receive message history (initial 20 messages)
socket.on('message_history', (history) => {
setMessages(history);
setHasMore(history.length === 20);
});
// Receive new messages
socket.on('event_message', (message) => {
setMessages((prev) => [...prev, message]);
});
@@ -77,6 +87,7 @@ const EventChatPage = () => {
socket.emit('leave_event_room', { eventId: parseInt(eventId) });
socket.off('connect');
socket.off('disconnect');
socket.off('message_history');
socket.off('event_message');
socket.off('active_users');
socket.off('user_joined');
@@ -103,6 +114,39 @@ const EventChatPage = () => {
setNewMessage('');
};
const loadOlderMessages = async () => {
if (loadingOlder || !hasMore || messages.length === 0) return;
setLoadingOlder(true);
try {
const oldestMessageId = messages[0].id;
const response = await eventsAPI.getMessages(eventId, oldestMessageId, 20);
if (response.data.length > 0) {
// Save current scroll position
const container = messagesContainerRef.current;
const oldScrollHeight = container.scrollHeight;
const oldScrollTop = container.scrollTop;
// Prepend older messages
setMessages((prev) => [...response.data, ...prev]);
setHasMore(response.hasMore);
// Restore scroll position (adjust for new content)
setTimeout(() => {
const newScrollHeight = container.scrollHeight;
container.scrollTop = oldScrollTop + (newScrollHeight - oldScrollHeight);
}, 0);
} else {
setHasMore(false);
}
} catch (error) {
console.error('Failed to load older messages:', error);
} finally {
setLoadingOlder(false);
}
};
const handleMatchWith = (userId) => {
// TODO: Implement match request
alert(`Match request sent to user!`);
@@ -111,6 +155,21 @@ const EventChatPage = () => {
}, 1000);
};
// Infinite scroll - detect scroll to top
useEffect(() => {
const container = messagesContainerRef.current;
if (!container) return;
const handleScroll = () => {
if (container.scrollTop < 100 && !loadingOlder && hasMore) {
loadOlderMessages();
}
};
container.addEventListener('scroll', handleScroll);
return () => container.removeEventListener('scroll', handleScroll);
}, [loadingOlder, hasMore, messages]);
if (!event) {
return (
<Layout>
@@ -176,7 +235,14 @@ const EventChatPage = () => {
{/* Chat Area */}
<div className="flex-1 flex flex-col">
{/* Messages */}
<div className="flex-1 overflow-y-auto p-4 space-y-4">
<div ref={messagesContainerRef} className="flex-1 overflow-y-auto p-4 space-y-4">
{/* Loading older messages indicator */}
{loadingOlder && (
<div className="flex justify-center py-2">
<Loader2 className="w-5 h-5 animate-spin text-primary-600" />
</div>
)}
{messages.length === 0 && (
<div className="text-center text-gray-500 py-8">
No messages yet. Start the conversation!

View File

@@ -163,6 +163,15 @@ export const eventsAPI = {
const data = await fetchAPI(`/events/${id}`);
return data.data;
},
async getMessages(eventId, before = null, limit = 20) {
const params = new URLSearchParams({ limit: limit.toString() });
if (before) {
params.append('before', before.toString());
}
const data = await fetchAPI(`/events/${eventId}/messages?${params}`);
return data;
},
};
export { ApiError };