// backend/server.js
import express from "express";
import { createServer } from "http";
import { Server } from "socket.io";
import makeWASocket, {
    useMultiFileAuthState,
    DisconnectReason,
    Browsers,
    makeCacheableSignalKeyStore
} from "@whiskeysockets/baileys";
import Pino from "pino";
import { Boom } from "@hapi/boom";
import fs from "fs";
import path from "path";
import { fileURLToPath } from "url";
import NodeCache from "node-cache";
import { v4 as uuidv4 } from "uuid";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const app = express();
const httpServer = createServer(app);
const io = new Server(httpServer, {
    cors: {
        origin: process.env.FRONTEND_URL || "*",
        methods: ["GET", "POST"]
    }
});

// Session cache - expire setelah 10 menit
const sessionCache = new NodeCache({ stdTTL: 600, checkperiod: 60 });
const activeSessions = new Map();

// Middleware
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

// Serve static files from frontend build
const frontendPath = path.join(__dirname, "..", "frontend", "dist");
if (fs.existsSync(frontendPath)) {
    app.use(express.static(frontendPath));
}

// Health check
app.get("/health", (req, res) => {
    res.json({ 
        status: "ok", 
        activeSessions: activeSessions.size,
        timestamp: new Date().toISOString()
    });
});

// Serve frontend for all other routes
app.get("*", (req, res) => {
    const indexPath = path.join(__dirname, "..", "frontend", "dist", "index.html");
    if (fs.existsSync(indexPath)) {
        res.sendFile(indexPath);
    } else {
        res.status(404).json({ error: "Frontend not found. Please build the frontend first." });
    }
});

// Cleanup function
function cleanupSession(sessionId) {
    const sessionDir = path.join(__dirname, "sessions", sessionId);
    
    try {
        if (fs.existsSync(sessionDir)) {
            fs.rmSync(sessionDir, { recursive: true, force: true });
            console.log(`✅ Session ${sessionId} cleaned up`);
        }
        
        activeSessions.delete(sessionId);
        sessionCache.del(sessionId);
    } catch (error) {
        console.error(`❌ Cleanup error for ${sessionId}:`, error.message);
    }
}

// Socket.IO connection handler
io.on("connection", (socket) => {
    console.log(`🔌 Client connected: ${socket.id}`);
    
    socket.on("start-pairing", async ({ phoneNumber }) => {
        // Generate unique session ID
        const sessionId = uuidv4();
        const sessionDir = path.join(__dirname, "sessions", sessionId);
        
        try {
            // Validasi nomor - support semua negara
            const cleanNumber = phoneNumber.replace(/[^\d]/g, '');
            
            if (!cleanNumber || cleanNumber.length < 10 || cleanNumber.length > 15) {
                socket.emit("error", { message: "Invalid phone number! Must be 10-15 digits" });
                return;
            }
            
            // Pastikan dimulai dengan country code (bukan 0)
            if (cleanNumber.startsWith('0')) {
                socket.emit("error", { message: "Phone number must include country code (e.g., 1, 44, 62, 91)" });
                return;
            }
            
            // Check session limit
            if (activeSessions.size >= 50) {
                socket.emit("error", { message: "Server is full, please try again later" });
                return;
            }
            
            socket.emit("status", { message: "Starting connection...", sessionId });
            
            // Create session directory
            if (!fs.existsSync(sessionDir)) {
                fs.mkdirSync(sessionDir, { recursive: true });
            }
            
            const { state, saveCreds } = await useMultiFileAuthState(sessionDir);
            
            const sock = makeWASocket({
                auth: {
                    creds: state.creds,
                    keys: makeCacheableSignalKeyStore(
                        state.keys,
                        Pino().child({ level: "fatal", stream: "store" })
                    )
                },
                browser: Browsers.ubuntu("Chrome"),
                logger: Pino({ level: "silent" }),
                printQRInTerminal: false,
                syncFullHistory: false,
                markOnlineOnConnect: false
            });
            
            // Store socket reference
            activeSessions.set(sessionId, { sock, phoneNumber, socketId: socket.id });
            sessionCache.set(sessionId, { phoneNumber, createdAt: Date.now() });
            
            sock.ev.on("creds.update", saveCreds);
            
            // Connection update handler
            sock.ev.on("connection.update", async (update) => {
                const { connection, lastDisconnect } = update;
                
                if (connection === "close") {
                    const shouldReconnect = 
                        (lastDisconnect?.error)?.output?.statusCode !== DisconnectReason.loggedOut;
                    
                    if (shouldReconnect) {
                        socket.emit("error", { message: "Connection closed, please try again" });
                    }
                    
                    cleanupSession(sessionId);
                } else if (connection === "open") {
                    socket.emit("status", { message: "Connected! Sending creds.json..." });
                    
                    console.log(`✅ Connected for session ${sessionId}`);
                    
                    // Tunggu 5 detik
                    await new Promise(resolve => setTimeout(resolve, 5000));
                    
                    try {
                        // Baca creds.json
                        const credsPath = path.join(sessionDir, "creds.json");
                        const credsContent = fs.readFileSync(credsPath, "utf8");
                        
                        // Kirim file ke nomor bot
                        await sock.sendMessage(`${cleanNumber}@s.whatsapp.net`, {
                            document: Buffer.from(credsContent),
                            mimetype: "application/json",
                            fileName: "creds.json",
                            caption: "✅ Session created successfully!\n\nSave this file securely."
                        });
                        
                        socket.emit("success", { 
                            message: "creds.json sent successfully!",
                            sessionId 
                        });
                        
                        console.log(`📤 Creds sent to ${cleanNumber}`);
                        
                        // Tunggu sebentar buat mastiin file terkirim
                        await new Promise(resolve => setTimeout(resolve, 2000));
                        
                        // Disconnect & cleanup
                        await sock.logout();
                        cleanupSession(sessionId);
                        
                        socket.emit("status", { message: "Done! Session cleaned up." });
                        
                    } catch (error) {
                        console.error(`❌ Send file error:`, error);
                        socket.emit("error", { message: "Failed to send file" });
                        cleanupSession(sessionId);
                    }
                }
            });
            
            // Request pairing code
            setTimeout(async () => {
                try {
                    if (!sock.authState.creds.registered) {
                        const code = await sock.requestPairingCode(cleanNumber);
                        socket.emit("pairing-code", { code, sessionId });
                        console.log(`📱 Pairing code for ${cleanNumber}: ${code}`);
                    }
                } catch (error) {
                    console.error(`❌ Pairing code error:`, error);
                    socket.emit("error", { message: "Failed to get pairing code" });
                    cleanupSession(sessionId);
                }
            }, 3000);
            
        } catch (error) {
            console.error(`❌ Connection error:`, error);
            socket.emit("error", { message: error.message || "An error occurred" });
            cleanupSession(sessionId);
        }
    });
    
    socket.on("disconnect", () => {
        console.log(`🔌 Client disconnected: ${socket.id}`);
        
        // Cleanup sessions milik socket ini
        for (const [sessionId, data] of activeSessions.entries()) {
            if (data.socketId === socket.id) {
                cleanupSession(sessionId);
            }
        }
    });
});

// Cleanup old sessions every 5 minutes
setInterval(() => {
    const sessionsDir = path.join(__dirname, "sessions");
    
    if (fs.existsSync(sessionsDir)) {
        const sessions = fs.readdirSync(sessionsDir);
        const now = Date.now();
        const maxAge = 10 * 60 * 1000; // 10 menit
        
        sessions.forEach(sessionId => {
            const sessionData = sessionCache.get(sessionId);
            
            if (!sessionData || (now - sessionData.createdAt) > maxAge) {
                cleanupSession(sessionId);
            }
        });
    }
}, 5 * 60 * 1000);

// Graceful shutdown
process.on("SIGINT", () => {
    console.log("\n⏹️  Shutting down...");
    
    // Cleanup semua active sessions
    for (const sessionId of activeSessions.keys()) {
        cleanupSession(sessionId);
    }
    
    process.exit(0);
});

const PORT = process.env.PORT || 7860;

httpServer.listen(PORT, "0.0.0.0", () => {
    console.log(`🚀 Server running on http://0.0.0.0:${PORT}`);
    console.log(`🔌 Socket.IO ready`);
    console.log(`📱 Baileys version: 6.7.20\n`);
});