server.js

const express = require("express");
const http = require("http");

const app = express();
const server = http.createServer(app);

// Store LED states
let ledStates = {
  led1: false,
  led2: false,
  led3: false,
  led4: false,
  chase: false
};

// Store SSE clients (ESP8266 devices)
let sseClients = [];

app.use(express.json());
app.use(express.static("."));

// SSE endpoint for ESP8266
app.get("/events", (req, res) => {
  res.setHeader("Content-Type", "text/event-stream");
  res.setHeader("Cache-Control", "no-cache");
  res.setHeader("Connection", "keep-alive");
  res.setHeader("Access-Control-Allow-Origin", "*");
  
  console.log("New SSE client connected");
  
  // Send current state immediately
  Object.keys(ledStates).forEach(led => {
    const message = `data: ${led}:${ledStates[led] ? 1 : 0}\n\n`;
    res.write(message);
    console.log(`Sent initial state: ${led}:${ledStates[led] ? 1 : 0}`);
  });
  
  // Add client to list
  sseClients.push(res);
  console.log(`Total ESP8266 clients: ${sseClients.length}`);
  
  // Send keepalive every 30 seconds
  const keepaliveInterval = setInterval(() => {
    try {
      res.write(`:keepalive\n\n`);
    } catch (err) {
      clearInterval(keepaliveInterval);
    }
  }, 30000);
  
  // Remove client on disconnect
  req.on("close", () => {
    clearInterval(keepaliveInterval);
    sseClients = sseClients.filter(client => client !== res);
    console.log(`ESP8266 disconnected. Total clients: ${sseClients.length}`);
  });
});

// Get current LED states (for frontend)
app.get("/api/leds", (req, res) => {
  res.json(ledStates);
});

// Get connection status
app.get("/api/status", (req, res) => {
  res.json({ 
    connected: sseClients.length > 0,
    clientCount: sseClients.length 
  });
});

// Toggle individual LED (for frontend)
app.post("/api/led/:ledName", (req, res) => {
  const { ledName } = req.params;
  const { state } = req.body;
  
  if (!ledStates.hasOwnProperty(ledName)) {
    return res.status(400).json({ error: "Invalid LED name" });
  }
  
  ledStates[ledName] = state;
  
  // If turning on chase, turn off individual LEDs 1-3
  if (ledName === "chase" && state) {
    ledStates.led1 = false;
    ledStates.led2 = false;
    ledStates.led3 = false;
  }
  
  // Broadcast to all ESP8266 devices via SSE
  const message = `data: ${ledName}:${state ? 1 : 0}\n\n`;
  console.log(`Broadcasting: ${ledName}:${state ? 1 : 0} to ${sseClients.length} clients`);
  
  sseClients.forEach((client, index) => {
    try {
      client.write(message);
    } catch (err) {
      console.error(`Error sending to client ${index}:`, err.message);
    }
  });
  
  // If chase was turned on, also send LED1-3 off commands
  if (ledName === "chase" && state) {
    ["led1", "led2", "led3"].forEach(led => {
      const msg = `data: ${led}:0\n\n`;
      console.log(`Broadcasting: ${led}:0`);
      sseClients.forEach(client => {
        try {
          client.write(msg);
        } catch (err) {
          console.error("Error sending to client:", err.message);
        }
      });
    });
  }
  
  console.log(`${ledName} set to ${state ? "ON" : "OFF"}`);
  res.json({ success: true, ledStates });
});

// Turn all LEDs off
app.post("/api/all-off", (req, res) => {
  Object.keys(ledStates).forEach(led => {
    ledStates[led] = false;
    const message = `data: ${led}:0\n\n`;
    console.log(`Broadcasting: ${led}:0`);
    sseClients.forEach(client => {
      try {
        client.write(message);
      } catch (err) {
        console.error("Error sending to client:", err.message);
      }
    });
  });
  
  console.log("All LEDs turned OFF");
  res.json({ success: true, ledStates });
});

const PORT = process.env.PORT || 3000;
const HOST = "0.0.0.0";
server.listen(PORT, HOST, () => {
  console.log(`\n=================================`);
  console.log(`Server running at http://${HOST}:${PORT}`);
  console.log(`SSE endpoint: http://${HOST}:${PORT}/events`);
  console.log(`API endpoint: http://${HOST}:${PORT}/api/leds`);
  console.log(`=================================\n`);
});