const { default: makeWASocket, useMultiFileAuthState, DisconnectReason, fetchLatestBaileysVersion } = require('@whiskeysockets/baileys');
const express = require('express');
const QRCode = require('qrcode');
const pino = require('pino');

const app = express();
app.use(express.json());

// Configurable via environment variables
const PORT = process.env.PORT || 21465;
const API_KEY = process.env.API_KEY || 'nexus-wpp-secret-2026';
const TENANT_ID = process.env.TENANT_ID || '';
const WEBHOOK_BASE = process.env.WEBHOOK_BASE || 'http://localhost:5001/pos/api/whatsapp/webhook';
const WEBHOOK_URL = TENANT_ID ? `${WEBHOOK_BASE}?tenant_id=${TENANT_ID}` : WEBHOOK_BASE;
const AUTH_DIR = process.env.AUTH_DIR || '/app/auth';

let sock = null;
let qrCode = null;
let connectionState = 'disconnected';
const logger = pino({ level: process.env.LOG_LEVEL || 'warn' });

async function connectWhatsApp() {
    const { state, saveCreds } = await useMultiFileAuthState(AUTH_DIR);
    const { version } = await fetchLatestBaileysVersion();
    console.log(`[Tenant ${TENANT_ID}] Connecting with Baileys v` + version.join('.'));
    connectionState = 'connecting';

    sock = makeWASocket({ version, auth: state, logger, printQRInTerminal: true, browser: ['Nexus POS', 'Chrome', '120.0'] });
    sock.ev.on('creds.update', saveCreds);

    sock.ev.on('connection.update', async (update) => {
        const { connection, lastDisconnect, qr } = update;
        if (qr) {
            qrCode = await QRCode.toDataURL(qr);
            connectionState = 'qr';
            console.log(`[Tenant ${TENANT_ID}] QR code generated!`);
        }
        if (connection === 'close') {
            connectionState = 'disconnected';
            qrCode = null;
            const reason = lastDisconnect?.error?.output?.statusCode;
            if (reason !== DisconnectReason.loggedOut) { setTimeout(connectWhatsApp, 5000); }
        }
        if (connection === 'open') { connectionState = 'open'; qrCode = null; console.log(`[Tenant ${TENANT_ID}] Connected!`); }
    });

    sock.ev.on('messages.upsert', async ({ messages }) => {
        for (const msg of messages) {
            if (msg.key.fromMe) continue;
            const phone = msg.key.remoteJid.replace('@s.whatsapp.net', '');
            const text = msg.message?.conversation || msg.message?.extendedTextMessage?.text || '';
            console.log(`[Tenant ${TENANT_ID}] From ${phone}: ${text}`);
            try {
                await fetch(WEBHOOK_URL, { method: 'POST', headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({ event: 'messages.upsert', data: { key: msg.key, message: msg.message, messageTimestamp: msg.messageTimestamp } }) });
            } catch (e) { console.log(`[Tenant ${TENANT_ID}] Webhook failed:`, e.message); }
        }
    });
}

app.get('/', (req, res) => res.json({ status: 'ok', service: 'Nexus WhatsApp Bridge', tenant: TENANT_ID, state: connectionState }));
app.get('/status', (req, res) => res.json({ state: connectionState, hasQr: !!qrCode }));
app.get('/qr', (req, res) => {
    if (connectionState === 'open') return res.json({ state: 'open', message: 'Already connected' });
    if (!qrCode) return res.json({ state: connectionState, qr: null, message: 'QR not ready' });
    res.json({ state: 'qr', qr: qrCode });
});
app.post('/connect', async (req, res) => { if (!sock) connectWhatsApp(); res.json({ state: connectionState }); });
app.post('/send', async (req, res) => {
    if (connectionState !== 'open') return res.status(400).json({ error: 'Not connected' });
    const { phone, message } = req.body;
    const jid = phone.includes('@') ? phone : phone + '@s.whatsapp.net';
    try { const r = await sock.sendMessage(jid, { text: message }); res.json({ success: true, id: r.key.id }); }
    catch (e) { res.status(500).json({ error: e.message }); }
});
app.post('/logout', async (req, res) => { if (sock) { await sock.logout(); sock = null; } qrCode = null; connectionState = 'disconnected'; res.json({ state: 'disconnected' }); });

app.listen(PORT, () => { console.log(`[Tenant ${TENANT_ID}] WhatsApp Bridge on port ${PORT}`); connectWhatsApp(); });