const { Client, LocalAuth } = require('whatsapp-web.js');
const express = require('express');
const qrcode = require('qrcode');
const fs = require('fs-extra');
const path = require('path');

const app = express();
app.use(express.json());
app.use(express.static(path.join(__dirname, 'ui')));

let lastQr = "";
let isReady = false;
let isInitializing = true;

// Fester Speicherort für die Session außerhalb flüchtiger Docker-Verzeichnisse
const SESSION_DATA = '/data/auth';

// Sauberes Herunterfahren bei Abstürzen, um Dateikorruption der Session zu verhindern
async function handleCrash(errorContext) {
    console.error(`💥 CRITICAL ERROR CAUGHT: ${errorContext}`);
    isReady = false;
    
    try {
        console.log('Versuche Browser sauber zu schließen, um Session zu retten...');
        if (client && client.pupBrowser) {
            await client.pupBrowser.close().catch(() => {});
        }
    } catch (e) {
        console.error('Browser konnte nicht sauber geschlossen werden:', e);
    }
    
    console.log('Add-on wird beendet. HA Watchdog startet es sauber neu...');
    process.exit(1); 
}

// Sicherheitsnetz für ungefangene Puppeteer/Browser-Fehler
process.on('uncaughtException', async (err) => {
    if (err.message.includes('ProtocolError') || err.message.includes('Runtime.callFunctionOn') || err.message.includes('Target closed')) {
        await handleCrash('Puppeteer Protocol Timeout / Crash');
    } else {
        console.error('Uncaught Exception:', err);
    }
});

process.on('unhandledRejection', async (reason, promise) => {
    if (reason && reason.message && reason.message.includes('Session closed')) {
        await handleCrash('Unhandled Puppeteer Session Rejection');
    } else {
        console.error('Unhandled Rejection at:', promise, 'reason:', reason);
    }
});

// Client-Definition mit fixierter Client-ID gegen Session-Verlust
const client = new Client({
    authStrategy: new LocalAuth({ 
        dataPath: SESSION_DATA,
        clientId: "ha_bridge_session" 
    }),
    authTimeoutMs: 90000, 
    qrMaxRetries: 5,
    puppeteer: {
        executablePath: '/usr/bin/chromium-browser',
        protocolTimeout: 0, 
        args: [
            '--no-sandbox', 
            '--disable-setuid-sandbox',
            '--disable-dev-shm-usage', 
            '--disable-gpu',
            '--no-first-run',
            '--no-zygote',
            '--single-process', 
            '--disable-extensions',
            '--disable-background-timer-throttling', 
            '--disable-backgrounding-occluded-windows',
            '--disable-renderer-backgrounding'
        ]
    }
});

// QR Code Handling
client.on('qr', (qr) => {
    lastQr = qr;
    isReady = false;
    isInitializing = false;
    console.log('Neuer QR Code generiert.');
});

client.on('ready', () => {
    isReady = true;
    lastQr = "";
    isInitializing = false;
    console.log('WhatsApp ist bereit! Session wurde erfolgreich geladen/gespeichert.');
});

client.on('disconnected', async (reason) => {
    console.log(`WhatsApp Verbindung manuell oder extern getrennt (Grund: ${reason}).`);
    await handleCrash('Externer Disconnect');
});

// --- ROUTES ---

app.get('/', (req, res) => {
    res.sendFile(path.join(__dirname, 'ui', 'index.html'));
});

app.get('/api/status', async (req, res) => {
    try {
        let qrData = null;
        if (lastQr) {
            qrData = await qrcode.toDataURL(lastQr);
        }
        
        let clientState = 'DISCONNECTED';
        if (isReady) {
            clientState = await client.getState().catch(() => 'ERROR');
        }

        res.json({ 
            isReady: isReady,
            hasQr: lastQr !== "",
            qrCode: qrData,
            isInitializing: isInitializing,
            clientState: clientState
        });
    } catch (e) {
        res.status(500).json({ error: e.message });
    }
});

// Logout & Session-Löschung (Nur bei explizitem Klick auf "Account wechseln")
app.post('/auth/logout', async (req, res) => {
    try {
        console.log("Manueller Logout über Web-UI...");
        await client.logout().catch(() => {});
        await fs.remove(path.join(SESSION_DATA, 'session-ha_bridge_session')).catch(() => {});
        res.json({ success: true, message: "Erfolgreich abgemeldet. Ordner gelöscht. Addon startet neu..." });
        setTimeout(() => process.exit(0), 2000);
    } catch (err) {
        res.status(500).json({ error: err.message });
    }
});

// Factory Reset
app.delete('/system/reset', async (req, res) => {
    try {
        await client.destroy().catch(() => {});
        await fs.emptyDir('/data').catch(() => {});
        res.json({ success: true, message: "Werkseinstellungen aktiv. Alles gelöscht. Neustart..." });
        setTimeout(() => process.exit(0), 2000);
    } catch (err) {
        res.status(500).json({ error: err.message });
    }
});

// Sende-Schnittstelle
app.post('/send', async (req, res) => {
    const { number, message } = req.body;
    if (!isReady) return res.status(503).json({ error: 'Client nicht bereit' });
    try {
        const chatId = number.includes('@c.us') ? number : `${number}@c.us`;
        await client.sendMessage(chatId, message);
        res.json({ success: true });
    } catch (err) {
        res.status(500).json({ error: err.message });
    }
});

console.log('Initialisiere WhatsApp Client...');
client.initialize().catch(async (err) => {
    await handleCrash(`Initialisierungsfehler: ${err.message}`);
});

app.listen(3000, () => console.log('WhatsApp Bridge Server läuft auf Port 3000'));