web-chat/backend/socket.js

const { Server } = require('socket.io');
const jwt = require('jsonwebtoken');
const jwtSecret = process.env.JWT_SECRET;
const { db } = require('./db.js');

function initializeSocket(server) {
    const io = new Server(server, {
        cookie: {
            httpOnly: true,
            sameSite: "strict",
            maxAge: 30 * 24 * 60 * 60 * 1000
        }
    });

    io.use((socket, next) => {
        const token = socket.handshake.auth.token;
        if(token) {
            jwt.verify(token, jwtSecret, (err, user) => {
                if(err) {
                    console.log(err);
                    return next(new Error('Authentication error'));
                }
                socket.user = user;
                next();
            });
        } else {
            next(new Error('Not logged in'));
        }
    });

    io.on('connection', (socket) => {
        if (!socket.user) {
            console.log('User not authenticated');
            socket.disconnect();
            return;
        }
        const username = socket.user.username;
        console.log(username + ' connected');

        // Join a room with the user's username
        socket.join(username);

        //loadInitialMessages(socket);

        // chat message event
        socket.on('chat message', async (msgData) => {
            const { content, recipient } = msgData;
            let insertedId;
            try {
                // Insert the new message into the database
                const result = await db.query('INSERT INTO messages (content, username, recipient) VALUES ($1, $2, $3) RETURNING id', [content, username, recipient]);
                insertedId = result.rows[0].id;
            } catch (err) {
                console.error('Error inserting message:', err);
                return;
            }

            // Fetch the newly inserted message from the database
            try {
                const query = 'SELECT id, content, username, recipient FROM messages WHERE id = $1';
                const result = await db.query(query, [insertedId]);

                if (result.rows.length > 0) {
                    const newMessage = result.rows[0];
                    const formattedMessage = `Username: ${newMessage.username}, recipient: ${newMessage.recipient}, message: ${newMessage.content}`;
                    console.log(formattedMessage);

                    // Emit message to the sender's and recipient's rooms
                    io.to(username).to(recipient).emit('chat message', { username: newMessage.username, recipient: newMessage.recipient, content: newMessage.content });
                }
            } catch (err) {
                console.error('Error fetching inserted message:', err);
            }


            if (!socket.recovered) {
                try {
                    const query = 'SELECT id, content, username, recipient FROM messages WHERE id > $1 ORDER BY id ASC';
                    const values = [socket.handshake.auth.serverOffset || 0];
                    const result = await db.query(query, values);
                    //const newMessage = result.rows[0];
                    for (const row of result.rows) {
                        if (row.username === username || row.recipient === username) {
                            io.to(username).to(recipient).emit('chat message', { username: row.username, recipient: row.recipient, content: row.content });

                        }
                    }
                } catch (e) {
                    console.error('Error retrieving messages:', e);
                }
            }
        });
        socket.on('get messages', async (recipient) => {
            const username = socket.user.username;
            try {
                const query = `
            SELECT id, content, username, recipient
            FROM messages
            WHERE (username = $1 AND recipient = $2) OR (username = $2 AND recipient = $1)
            ORDER BY id ASC
        `;
                const result = await db.query(query, [username, recipient]);

                if (result.rows.length > 0) {
                    //const { username: sender, recipient: receiver, content: content, id: id } = result.rows;
                    console.log('Sending messages:', result.rows);
                    socket.emit('messages history', result.rows);
                }
            } catch (e) {
                console.error('Error retrieving messages:', e);
            }
        });

        // disconnect event
        socket.on('disconnect', () => {
            console.log(username + ' has disconnected');
        });
    });

    return io;
}

async function loadInitialMessages(socket) {
    const username = socket.user.username;
    try {
        const query = 'SELECT id, content, username, recipient FROM messages WHERE username = $1 OR recipient = $1 ORDER BY id DESC LIMIT 50';
        const result = await db.query(query, [username]);

        for (const row of result.rows.reverse()) {
            socket.emit('chat message',row.username, row.recipient, row.content);
        }

        // Set the server offset to the latest message id
        if (result.rows.length > 0) {
            socket.handshake.auth.serverOffset = result.rows[result.rows.length - 1].id;
        }
    } catch (e) {
        console.error('Error retrieving initial messages:', e);
    }
}

module.exports = { initializeSocket };