const express = require('express');
const http = require('http');
const { Server } = require('socket.io');
const cors = require('cors');
require('dotenv').config();

const app = express();
const server = http.createServer(app);
const io = new Server(server, {
    cors: {
        origin: '*',
        methods: ['GET', 'POST']
    }
});

const authRoutes = require('./routes/auth');
const channelRoutes = require('./routes/channels');

app.use(cors());
app.use(express.json());

app.use('/api/auth', authRoutes);
app.use('/api/channels', channelRoutes);

app.get('/', (req, res) => {
    res.send('Secure Chat Backend Running');
});

const redisClient = require('./redis');
const db = require('./db');

io.on('connection', (socket) => {
    console.log('User connected:', socket.id);

    socket.on('join_channel', async (channelId) => {
        socket.join(channelId);
        console.log(`User ${socket.id} joined channel ${channelId}`);
        // Load recent messages
        try {
            const result = await db.query(
                `SELECT m.*, u.username, u.public_signing_key 
                 FROM messages m 
                 JOIN users u ON m.sender_id = u.id 
                 WHERE m.channel_id = $1 
                 ORDER BY m.created_at DESC LIMIT 50`,
                [channelId]
            );
            socket.emit('recent_messages', result.rows.reverse());
        } catch (err) {
            console.error('Error fetching messages:', err);
        }
    });

    socket.on('send_message', async (data) => {
        // data: { channelId, senderId, ciphertext, nonce, signature, keyVersion }
        const { channelId, senderId, ciphertext, nonce, signature, keyVersion } = data;

        try {
            // Store in DB
            const result = await db.query(
                `INSERT INTO messages (channel_id, sender_id, ciphertext, nonce, signature, key_version)
                 VALUES ($1, $2, $3, $4, $5, $6) RETURNING id, created_at`,
                [channelId, senderId, ciphertext, nonce, signature, keyVersion]
            );

            const message = {
                id: result.rows[0].id,
                created_at: result.rows[0].created_at,
                ...data
            };

            // Get username and signing key for display/verification
            const userRes = await db.query('SELECT username, public_signing_key FROM users WHERE id = $1', [senderId]);
            if (userRes.rows.length > 0) {
                message.username = userRes.rows[0].username;
                message.public_signing_key = userRes.rows[0].public_signing_key;
            }

            // Broadcast to channel
            io.to(channelId).emit('new_message', message);
        } catch (err) {
            console.error('Error saving message:', err);
        }
    });

    socket.on('typing', (data) => {
        socket.to(data.channelId).emit('user_typing', { username: data.username });
    });

    socket.on('disconnect', () => {
        console.log('User disconnected:', socket.id);
    });
});

const PORT = process.env.PORT || 3000;
server.listen(PORT, () => {
    console.log(`Server running on port ${PORT}`);
});