app.js

// --- 1. IMPORTS & SETUP ---
require("dotenv").config();
const express = require("express");
const cors = require("cors");
const morgan = require("morgan");
const http = require("http");
const path = require("path"); // Penting untuk kirim file HTML
const { Server } = require("socket.io");

// Inisialisasi App
const app = express();
const PORT = process.env.PORT || 3000;

// Bungkus Express dengan HTTP Server (Wajib untuk Socket.io)
const server = http.createServer(app);

// Setup Socket.io
const io = new Server(server, {
  cors: {
    origin: "*",
    methods: ["GET", "POST"],
  },
});

// --- 2. MIDDLEWARE ---
app.use(morgan("dev"));
app.use(express.json());
app.use(express.urlencoded({ extended: true }));
app.use(cors());

// [PENTING] Jadikan folder ini PUBLIC agar client.js dan style.css bisa dibaca browser
app.use(express.static(__dirname));

// --- 3. ROUTES ---

// Route Utama: Saat buka localhost:3000, kirim index.html
app.get("/", (req, res) => {
  res.sendFile(path.join(__dirname, "index.html"));
});

// --- 4. LOGIKA SOCKET (Jantung Aplikasi Chat) ---
io.on("connection", (socket) => {
  console.log(`⚡ User Connected: ${socket.id}`);

  // Event: User join ke room
  socket.on("join_room", (room) => {
    socket.join(room);
    console.log(`User ${socket.id} joined room: ${room}`);
  });

  // Event: User kirim pesan
  socket.on("send_message", (data) => {
    console.log(`Message from ${data.username}: ${data.message}`);

    // Broadcast pesan ke orang lain di room yang sama
    socket.to(data.room).emit("receive_message", data);
  });

  // Event: User keluar
  socket.on("disconnect", () => {
    console.log("User Disconnected", socket.id);
  });
});

// --- 5. START SERVER ---
// Gunakan 'server.listen' (bukan app.listen)
server.listen(PORT, () => {
  console.log(`\n🚀 ASync Realtime Server berjalan di port: ${PORT}`);
  console.log(`🔗 Buka di browser: http://localhost:${PORT}`);
});