// server.js – minimal Express + Socket.io + Redis subscriber
const http  = require('http');
const express = require('express');
const { Server } = require('socket.io');
const { createClient } = require('redis');

const app   = express();
const server = http.createServer(app);
const io    = new Server(server);

// ---------- 1. Settings ----------
const REDIS_URL   = 'redis://0.0.0.0:6379'; // adjust if needed
const REDIS_CHANNEL = 'temp_hum';           // channel you subscribed to

// ---------- 2. Serve static files ----------
app.use(express.static('public'));  // public contains index.php, src/… etc.

// ---------- 3. Redis subscriber ----------
const redisClient = createClient({ url: REDIS_URL });
redisClient.on('error', err => console.error('Redis error:', err));

async function startRedis() {
    await redisClient.connect();
    const sub = redisClient.duplicate();
    await sub.connect();

    // Helper: forward a Redis message to all Socket.io clients
    const forward = (msg) => {
        try {
            const payload = JSON.parse(msg);
            io.emit('temp_hum', payload);  // event name matches the JS listener
        } catch (e) {
            console.error('Failed to parse Redis message:', e);
        }
    };

    await sub.subscribe(REDIS_CHANNEL, forward);
    console.log(`Subscribed to Redis channel "${REDIS_CHANNEL}"`);
}

startRedis().catch(console.error);

// ---------- 4. Socket.io ----------
io.on('connection', socket => {
    console.log('Socket.io client connected:', socket.id);

    // Optionally send the most recent snapshot
    // (If you keep a cache, emit it here)

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

// ---------- 5. Start HTTP server ----------
const PORT = process.env.PORT || 3000;
server.listen(PORT, () => {
    console.log(`Dashboard server listening on http://localhost:${PORT}`);
});