const express = require('express');
const { Pool } = require('pg');
const path = require('path');
const puppeteer = require('puppeteer');
const fs = require('fs').promises;
const multer = require('multer');
const OAuthClient = require('intuit-oauth');
const { makeQboApiCall, getOAuthClient, saveTokens, resetOAuthClient } = require('./qbo_helper');

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

// Global browser instance
let browser = null;

// Initialize browser on startup
async function initBrowser() {
    if (!browser) {
        console.log('[BROWSER] Launching persistent browser...');
        browser = await puppeteer.launch({
            headless: 'new',
            args: [
                '--no-sandbox',
                '--disable-setuid-sandbox',
                '--disable-dev-shm-usage',
                '--disable-gpu',
                '--disable-software-rasterizer',
                '--no-zygote',
                '--single-process'
            ],
            protocolTimeout: 180000,
            timeout: 180000
        });
        console.log('[BROWSER] Browser launched and ready');
        
        // Restart browser if it crashes
        browser.on('disconnected', () => {
            console.log('[BROWSER] Browser disconnected, restarting...');
            browser = null;
            initBrowser();
        });
    }
    return browser;
}

// Database connection
const pool = new Pool({
    user: process.env.DB_USER || 'postgres',
    host: process.env.DB_HOST || 'localhost',
    database: process.env.DB_NAME || 'quotes_db',
    password: process.env.DB_PASSWORD || 'postgres',
    port: process.env.DB_PORT || 5432,
});

// Middleware
app.use(express.json());
app.use(express.static('public'));

// Configure multer for logo upload
const storage = multer.diskStorage({
    destination: async (req, file, cb) => {
        const uploadDir = path.join(__dirname, 'public', 'uploads');
        try {
            await fs.mkdir(uploadDir, { recursive: true });
        } catch (err) {
            console.error('Error creating upload directory:', err);
        }
        cb(null, uploadDir);
    },
    filename: (req, file, cb) => {
        cb(null, 'company-logo.png');
    }
});

const upload = multer({
    storage: storage,
    limits: { fileSize: 5 * 1024 * 1024 },
    fileFilter: (req, file, cb) => {
        if (file.mimetype.startsWith('image/')) {
            cb(null, true);
        } else {
            cb(new Error('Only image files are allowed'));
        }
    }
});

// Helper functions
function formatDate(date) {
    const d = new Date(date);
    const month = String(d.getMonth() + 1).padStart(2, '0');
    const day = String(d.getDate()).padStart(2, '0');
    const year = d.getFullYear();
    return `${month}/${day}/${year}`;
}

async function getNextQuoteNumber() {
    const year = new Date().getFullYear();
    const result = await pool.query(
        'SELECT quote_number FROM quotes WHERE quote_number LIKE $1 ORDER BY quote_number DESC LIMIT 1',
        [`${year}-%`]
    );
    
    if (result.rows.length === 0) {
        return `${year}-001`;
    }
    
    const lastNumber = parseInt(result.rows[0].quote_number.split('-')[1]);
    const nextNumber = String(lastNumber + 1).padStart(3, '0');
    return `${year}-${nextNumber}`;
}

async function getNextInvoiceNumber() {
    const result = await pool.query(
        'SELECT MAX(CAST(invoice_number AS INTEGER)) as max_number FROM invoices WHERE invoice_number ~ \'^[0-9]+$\''
    );
    
    if (result.rows.length === 0 || result.rows[0].max_number === null) {
        return '110508';
    }
    
    return String(parseInt(result.rows[0].max_number) + 1);
}

// Logo endpoints
app.get('/api/logo-info', async (req, res) => {
    try {
        const logoPath = path.join(__dirname, 'public', 'uploads', 'company-logo.png');
        try {
            await fs.access(logoPath);
            res.json({ hasLogo: true, logoPath: '/uploads/company-logo.png' });
        } catch {
            res.json({ hasLogo: false });
        }
    } catch (error) {
        console.error('Error checking logo:', error);
        res.status(500).json({ error: 'Error checking logo' });
    }
});

app.post('/api/upload-logo', upload.single('logo'), async (req, res) => {
    try {
        if (!req.file) {
            return res.status(400).json({ error: 'No file uploaded' });
        }
        res.json({ 
            message: 'Logo uploaded successfully',
            path: '/uploads/company-logo.png'
        });
    } catch (error) {
        console.error('Upload error:', error);
        res.status(500).json({ error: 'Error uploading logo' });
    }
});

// Customer endpoints
app.get('/api/customers', async (req, res) => {
    try {
        const result = await pool.query('SELECT * FROM customers ORDER BY name');
        res.json(result.rows);
    } catch (error) {
        console.error('Error fetching customers:', error);
        res.status(500).json({ error: 'Error fetching customers' });
    }
});

// POST /api/customers
app.post('/api/customers', async (req, res) => {
    // line1 bis line4 statt street/pobox/suite
    const { 
        name, line1, line2, line3, line4, city, state, zip_code, 
        account_number, email, phone, phone2, taxable 
    } = req.body;
    
    try {
        const result = await pool.query(
            `INSERT INTO customers 
             (name, line1, line2, line3, line4, city, state, 
             zip_code, account_number, email, phone, phone2, taxable) 
             VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13) 
             RETURNING *`,
            [name, line1 || null, line2 || null, line3 || null, line4 || null, 
             city || null, state || null, zip_code || null, 
             account_number || null, email || null, phone || null, phone2 || null, 
             taxable !== undefined ? taxable : true]
        );
        res.json(result.rows[0]);
    } catch (error) {
        console.error('Error creating customer:', error);
        res.status(500).json({ error: 'Error creating customer' });
    }
});

// PUT /api/customers/:id
app.put('/api/customers/:id', async (req, res) => {
    const { id } = req.params;
    const { 
        name, line1, line2, line3, line4, city, state, zip_code, 
        account_number, email, phone, phone2, taxable 
    } = req.body;
    
    try {
        const result = await pool.query(
            `UPDATE customers 
             SET name = $1, line1 = $2, line2 = $3, line3 = $4, line4 = $5, 
                 city = $6, state = $7, zip_code = $8, account_number = $9, email = $10, 
                 phone = $11, phone2 = $12, taxable = $13, updated_at = CURRENT_TIMESTAMP 
             WHERE id = $14 
             RETURNING *`,
            [name, line1 || null, line2 || null, line3 || null, line4 || null, 
             city || null, state || null, zip_code || null, 
             account_number || null, email || null, phone || null, phone2 || null,
             taxable !== undefined ? taxable : true, id]
        );
        res.json(result.rows[0]);
    } catch (error) {
        console.error('Error updating customer:', error);
        res.status(500).json({ error: 'Error updating customer' });
    }
});

app.delete('/api/customers/:id', async (req, res) => {
    const { id } = req.params;
    try {
        await pool.query('DELETE FROM customers WHERE id = $1', [id]);
        res.json({ success: true });
    } catch (error) {
        console.error('Error deleting customer:', error);
        res.status(500).json({ error: 'Error deleting customer' });
    }
});

// Quote endpoints
app.get('/api/quotes', async (req, res) => {
    try {
        const result = await pool.query(`
            SELECT q.*, c.name as customer_name
            FROM quotes q
            LEFT JOIN customers c ON q.customer_id = c.id
            ORDER BY q.created_at DESC
        `);
        res.json(result.rows);
    } catch (error) {
        console.error('Error fetching quotes:', error);
        res.status(500).json({ error: 'Error fetching quotes' });
    }
});

app.get('/api/quotes/:id', async (req, res) => {
    const { id } = req.params;
    try {
        // KORRIGIERT: c.line1...c.line4 statt c.street
        const quoteResult = await pool.query(`
            SELECT q.*, c.name as customer_name, c.line1, c.line2, c.line3, c.line4, c.city, c.state, c.zip_code, c.account_number
            FROM quotes q
            LEFT JOIN customers c ON q.customer_id = c.id
            WHERE q.id = $1
        `, [id]);
        
        if (quoteResult.rows.length === 0) {
            return res.status(404).json({ error: 'Quote not found' });
        }
        
        const itemsResult = await pool.query(
            'SELECT * FROM quote_items WHERE quote_id = $1 ORDER BY item_order',
            [id]
        );
        
        res.json({
            quote: quoteResult.rows[0],
            items: itemsResult.rows
        });
    } catch (error) {
        console.error('Error fetching quote:', error);
        res.status(500).json({ error: 'Error fetching quote' });
    }
});

app.post('/api/quotes', async (req, res) => {
    const { customer_id, quote_date, tax_exempt, items } = req.body;
    
    const client = await pool.connect();
    try {
        await client.query('BEGIN');
        
        const quote_number = await getNextQuoteNumber();
        
        let subtotal = 0;
        let has_tbd = false;
        
        for (const item of items) {
            if (item.rate.toUpperCase() === 'TBD' || item.amount.toUpperCase() === 'TBD') {
                has_tbd = true;
            } else {
                const amount = parseFloat(item.amount.replace(/[$,]/g, ''));
                if (!isNaN(amount)) {
                    subtotal += amount;
                }
            }
        }
        
        const tax_rate = 8.25;
        const tax_amount = tax_exempt ? 0 : (subtotal * tax_rate / 100);
        const total = subtotal + tax_amount;
        
        const quoteResult = await client.query(
            `INSERT INTO quotes (quote_number, customer_id, quote_date, tax_exempt, tax_rate, subtotal, tax_amount, total, has_tbd)
             VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9) RETURNING *`,
            [quote_number, customer_id, quote_date, tax_exempt, tax_rate, subtotal, tax_amount, total, has_tbd]
        );
        
        const quoteId = quoteResult.rows[0].id;
        
        for (let i = 0; i < items.length; i++) {
            await client.query(
                'INSERT INTO quote_items (quote_id, quantity, description, rate, amount, item_order, qbo_item_id) VALUES ($1, $2, $3, $4, $5, $6, $7)',
                [quoteId, items[i].quantity, items[i].description, items[i].rate, items[i].amount, i, items[i].qbo_item_id || '9']
            );
        }
        
        await client.query('COMMIT');
        res.json(quoteResult.rows[0]);
    } catch (error) {
        await client.query('ROLLBACK');
        console.error('Error creating quote:', error);
        res.status(500).json({ error: 'Error creating quote' });
    } finally {
        client.release();
    }
});

app.put('/api/quotes/:id', async (req, res) => {
    const { id } = req.params;
    const { customer_id, quote_date, tax_exempt, items } = req.body;
    
    const client = await pool.connect();
    try {
        await client.query('BEGIN');
        
        let subtotal = 0;
        let has_tbd = false;
        
        for (const item of items) {
            if (item.rate.toUpperCase() === 'TBD' || item.amount.toUpperCase() === 'TBD') {
                has_tbd = true;
            } else {
                const amount = parseFloat(item.amount.replace(/[$,]/g, ''));
                if (!isNaN(amount)) {
                    subtotal += amount;
                }
            }
        }
        
        const tax_rate = 8.25;
        const tax_amount = tax_exempt ? 0 : (subtotal * tax_rate / 100);
        const total = subtotal + tax_amount;
        
        await client.query(
            `UPDATE quotes SET customer_id = $1, quote_date = $2, tax_exempt = $3, tax_rate = $4, 
             subtotal = $5, tax_amount = $6, total = $7, has_tbd = $8, updated_at = CURRENT_TIMESTAMP
             WHERE id = $9`,
            [customer_id, quote_date, tax_exempt, tax_rate, subtotal, tax_amount, total, has_tbd, id]
        );
        
        await client.query('DELETE FROM quote_items WHERE quote_id = $1', [id]);
        
        for (let i = 0; i < items.length; i++) {
            await client.query(
                'INSERT INTO quote_items (quote_id, quantity, description, rate, amount, item_order, qbo_item_id) VALUES ($1, $2, $3, $4, $5, $6, $7)',
                [id, items[i].quantity, items[i].description, items[i].rate, items[i].amount, i, items[i].qbo_item_id || '9']
            );
        }
        
        await client.query('COMMIT');
        res.json({ success: true });
    } catch (error) {
        await client.query('ROLLBACK');
        console.error('Error updating quote:', error);
        res.status(500).json({ error: 'Error updating quote' });
    } finally {
        client.release();
    }
});

app.delete('/api/quotes/:id', async (req, res) => {
    const { id } = req.params;
    const client = await pool.connect();
    try {
        await client.query('BEGIN');
        await client.query('DELETE FROM quote_items WHERE quote_id = $1', [id]);
        await client.query('DELETE FROM quotes WHERE id = $1', [id]);
        await client.query('COMMIT');
        res.json({ success: true });
    } catch (error) {
        await client.query('ROLLBACK');
        console.error('Error deleting quote:', error);
        res.status(500).json({ error: 'Error deleting quote' });
    } finally {
        client.release();
    }
});

// Invoice endpoints
app.get('/api/invoices', async (req, res) => {
    try {
        const result = await pool.query(`
            SELECT i.*, c.name as customer_name
            FROM invoices i
            LEFT JOIN customers c ON i.customer_id = c.id
            ORDER BY i.created_at DESC
        `);
        res.json(result.rows);
    } catch (error) {
        console.error('Error fetching invoices:', error);
        res.status(500).json({ error: 'Error fetching invoices' });
    }
});

// IMPORTANT: This must come BEFORE /api/invoices/:id to avoid route collision
app.get('/api/invoices/next-number', async (req, res) => {
    try {
        const nextNumber = await getNextInvoiceNumber();
        res.json({ next_number: nextNumber });
    } catch (error) {
        console.error('Error getting next invoice number:', error);
        res.status(500).json({ error: 'Error getting next invoice number' });
    }
});

app.get('/api/invoices/:id', async (req, res) => {
    const { id } = req.params;
    try {
        // KORRIGIERT: c.line1, c.line2, c.line3, c.line4 statt c.street
        const invoiceResult = await pool.query(`
            SELECT i.*, c.name as customer_name, c.line1, c.line2, c.line3, c.line4, c.city, c.state, c.zip_code, c.account_number
            FROM invoices i
            LEFT JOIN customers c ON i.customer_id = c.id
            WHERE i.id = $1
        `, [id]);
        
        if (invoiceResult.rows.length === 0) {
            return res.status(404).json({ error: 'Invoice not found' });
        }
        
        const itemsResult = await pool.query(
            'SELECT * FROM invoice_items WHERE invoice_id = $1 ORDER BY item_order',
            [id]
        );
        
        res.json({
            invoice: invoiceResult.rows[0],
            items: itemsResult.rows
        });
    } catch (error) {
        console.error('Error fetching invoice:', error);
        res.status(500).json({ error: 'Error fetching invoice' });
    }
});

app.post('/api/invoices', async (req, res) => {
    const { invoice_number, customer_id, invoice_date, terms, auth_code, tax_exempt, items, created_from_quote_id, scheduled_send_date } = req.body;
    
    const client = await pool.connect();
    try {
        await client.query('BEGIN');
        
        // invoice_number ist jetzt OPTIONAL — wird erst beim QBO Export vergeben
        // Wenn angegeben, muss sie numerisch sein und darf nicht existieren
        if (invoice_number && invoice_number.trim() !== '') {
            if (!/^\d+$/.test(invoice_number)) {
                await client.query('ROLLBACK');
                return res.status(400).json({ error: 'Invalid invoice number. Must be a numeric value.' });
            }
            
            const existingInvoice = await client.query(
                'SELECT id FROM invoices WHERE invoice_number = $1',
                [invoice_number]
            );
            
            if (existingInvoice.rows.length > 0) {
                await client.query('ROLLBACK');
                return res.status(400).json({ error: `Invoice number ${invoice_number} already exists.` });
            }
        }
        
        let subtotal = 0;
        for (const item of items) {
            const amount = parseFloat(item.amount.replace(/[$,]/g, ''));
            if (!isNaN(amount)) {
                subtotal += amount;
            }
        }
        
        const tax_rate = 8.25;
        const tax_amount = tax_exempt ? 0 : (subtotal * tax_rate / 100);
        const total = subtotal + tax_amount;
        
        // invoice_number kann NULL sein
        const invNum = (invoice_number && invoice_number.trim() !== '') ? invoice_number : null;
        const sendDate = scheduled_send_date || null;
        
        const invoiceResult = await client.query(
            `INSERT INTO invoices (invoice_number, customer_id, invoice_date, terms, auth_code, tax_exempt, tax_rate, subtotal, tax_amount, total, created_from_quote_id, scheduled_send_date)
             VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12) RETURNING *`,
            [invNum, customer_id, invoice_date, terms, auth_code, tax_exempt, tax_rate, subtotal, tax_amount, total, created_from_quote_id, sendDate]
        );
        
        const invoiceId = invoiceResult.rows[0].id;
        
        for (let i = 0; i < items.length; i++) {
            await client.query(
                'INSERT INTO invoice_items (invoice_id, quantity, description, rate, amount, item_order, qbo_item_id) VALUES ($1, $2, $3, $4, $5, $6, $7)',
                [invoiceId, items[i].quantity, items[i].description, items[i].rate, items[i].amount, i, items[i].qbo_item_id || '9']
            );
        }
        
        await client.query('COMMIT');
        res.json(invoiceResult.rows[0]);
    } catch (error) {
        await client.query('ROLLBACK');
        console.error('Error creating invoice:', error);
        res.status(500).json({ error: 'Error creating invoice' });
    } finally {
        client.release();
    }
});

app.post('/api/quotes/:id/convert-to-invoice', async (req, res) => {
    const { id } = req.params;
    
    const client = await pool.connect();
    try {
        await client.query('BEGIN');
        
        // KORRIGIERT: c.line1...c.line4 statt c.street
        const quoteResult = await pool.query(`
            SELECT q.*, c.name as customer_name, c.line1, c.line2, c.line3, c.line4, c.city, c.state, c.zip_code, c.account_number
            FROM quotes q
            LEFT JOIN customers c ON q.customer_id = c.id
            WHERE q.id = $1
        `, [id]);
        
        if (quoteResult.rows.length === 0) {
            await client.query('ROLLBACK');
            return res.status(404).json({ error: 'Quote not found' });
        }
        
        const quote = quoteResult.rows[0];
        
        const itemsResult = await pool.query(
            'SELECT * FROM quote_items WHERE quote_id = $1 ORDER BY item_order',
            [id]
        );
        
        const hasTBD = itemsResult.rows.some(item => 
            item.rate.toUpperCase() === 'TBD' || item.amount.toUpperCase() === 'TBD'
        );
        
        if (hasTBD) {
            await client.query('ROLLBACK');
            return res.status(400).json({ error: 'Cannot convert quote with TBD items to invoice. Please update all TBD items first.' });
        }
        
        const invoice_number = null; 
        const invoiceDate = new Date().toISOString().split('T')[0];
        
        const invoiceResult = await client.query(
            `INSERT INTO invoices (invoice_number, customer_id, invoice_date, terms, auth_code, tax_exempt, tax_rate, subtotal, tax_amount, total, created_from_quote_id)
             VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11) RETURNING *`,
            [invoice_number, quote.customer_id, invoiceDate, 'Net 30', '', quote.tax_exempt, quote.tax_rate, quote.subtotal, quote.tax_amount, quote.total, id]
        );
        
        const invoiceId = invoiceResult.rows[0].id;
        
        for (let i = 0; i < itemsResult.rows.length; i++) {
            const item = itemsResult.rows[i];
            await client.query(
                'INSERT INTO invoice_items (invoice_id, quantity, description, rate, amount, item_order, qbo_item_id) VALUES ($1, $2, $3, $4, $5, $6, $7)',
                [invoiceId, item.quantity, item.description, item.rate, item.amount, i, item.qbo_item_id || '9']
            );
        }
        
        await client.query('COMMIT');
        res.json(invoiceResult.rows[0]);
    } catch (error) {
        await client.query('ROLLBACK');
        console.error('Error converting quote to invoice:', error);
        res.status(500).json({ error: 'Error converting quote to invoice' });
    } finally {
        client.release();
    }
});

app.put('/api/invoices/:id', async (req, res) => {
    const { id } = req.params;
    const { invoice_number, customer_id, invoice_date, terms, auth_code, tax_exempt, items, scheduled_send_date } = req.body;
    
    const client = await pool.connect();
    try {
        await client.query('BEGIN');
        
        // invoice_number ist optional. Wenn angegeben und nicht leer, muss sie numerisch sein
        const invNum = (invoice_number && invoice_number.trim() !== '') ? invoice_number : null;
        
        if (invNum && !/^\d+$/.test(invNum)) {
            await client.query('ROLLBACK');
            return res.status(400).json({ error: 'Invalid invoice number. Must be a numeric value.' });
        }
        
        if (invNum) {
            const existingInvoice = await client.query(
                'SELECT id FROM invoices WHERE invoice_number = $1 AND id != $2',
                [invNum, id]
            );
            if (existingInvoice.rows.length > 0) {
                await client.query('ROLLBACK');
                return res.status(400).json({ error: `Invoice number ${invNum} already exists.` });
            }
        }
        
        let subtotal = 0;
        for (const item of items) {
            const amount = parseFloat(item.amount.replace(/[$,]/g, ''));
            if (!isNaN(amount)) {
                subtotal += amount;
            }
        }
        
        const tax_rate = 8.25;
        const tax_amount = tax_exempt ? 0 : (subtotal * tax_rate / 100);
        const total = subtotal + tax_amount;
        const sendDate = scheduled_send_date || null;
        
        await client.query(
            `UPDATE invoices SET invoice_number = $1, customer_id = $2, invoice_date = $3, terms = $4, auth_code = $5, tax_exempt = $6, 
             tax_rate = $7, subtotal = $8, tax_amount = $9, total = $10, scheduled_send_date = $11, updated_at = CURRENT_TIMESTAMP
             WHERE id = $12`,
            [invNum, customer_id, invoice_date, terms, auth_code, tax_exempt, tax_rate, subtotal, tax_amount, total, sendDate, id]
        );
        
        await client.query('DELETE FROM invoice_items WHERE invoice_id = $1', [id]);
        
        for (let i = 0; i < items.length; i++) {
            await client.query(
                'INSERT INTO invoice_items (invoice_id, quantity, description, rate, amount, item_order, qbo_item_id) VALUES ($1, $2, $3, $4, $5, $6, $7)',
                [id, items[i].quantity, items[i].description, items[i].rate, items[i].amount, i, items[i].qbo_item_id || '9']
            );
        }
        
        await client.query('COMMIT');
        res.json({ success: true });
    } catch (error) {
        await client.query('ROLLBACK');
        console.error('Error updating invoice:', error);
        res.status(500).json({ error: 'Error updating invoice' });
    } finally {
        client.release();
    }
});


app.delete('/api/invoices/:id', async (req, res) => {
    const { id } = req.params;
    const client = await pool.connect();
    try {
        await client.query('BEGIN');
        await client.query('DELETE FROM invoice_items WHERE invoice_id = $1', [id]);
        await client.query('DELETE FROM invoices WHERE id = $1', [id]);
        await client.query('COMMIT');
        res.json({ success: true });
    } catch (error) {
        await client.query('ROLLBACK');
        console.error('Error deleting invoice:', error);
        res.status(500).json({ error: 'Error deleting invoice' });
    } finally {
        client.release();
    }
});

// PDF Generation code continues below...

// PDF Generation using templates and persistent browser
app.get('/api/quotes/:id/pdf', async (req, res) => {
    const { id } = req.params;
    
    console.log(`[PDF] Starting quote PDF generation for ID: ${id}`);
    
    try {
        // KORRIGIERT: Abfrage von line1-4 statt street/pobox
        const quoteResult = await pool.query(`
            SELECT q.*, c.name as customer_name, c.line1, c.line2, c.line3, c.line4, c.city, c.state, c.zip_code, c.account_number
            FROM quotes q
            LEFT JOIN customers c ON q.customer_id = c.id
            WHERE q.id = $1
        `, [id]);
        
        if (quoteResult.rows.length === 0) {
            return res.status(404).json({ error: 'Quote not found' });
        }
        
        const quote = quoteResult.rows[0];
        const itemsResult = await pool.query(
            'SELECT * FROM quote_items WHERE quote_id = $1 ORDER BY item_order',
            [id]
        );
        
        const templatePath = path.join(__dirname, 'templates', 'quote-template.html');
        let html = await fs.readFile(templatePath, 'utf-8');
        
        let logoHTML = '';
        try {
            const logoPath = path.join(__dirname, 'public', 'uploads', 'company-logo.png');
            const logoData = await fs.readFile(logoPath);
            const logoBase64 = logoData.toString('base64');
            logoHTML = `<img src="data:image/png;base64,${logoBase64}" alt="Company Logo" class="logo logo-size">`;
        } catch (err) {}
        
        // Items HTML generieren
        let itemsHTML = itemsResult.rows.map(item => {
            let rateFormatted = item.rate;
            if (item.rate.toUpperCase() !== 'TBD' && !item.rate.includes('/')) {
                const rateNum = parseFloat(item.rate.replace(/[^0-9.]/g, ''));
                if (!isNaN(rateNum)) rateFormatted = rateNum.toFixed(2);
            }
            return `
            <tr>
                <td class="qty">${item.quantity}</td>
                <td class="description">${item.description}</td>
                <td class="rate">${rateFormatted}</td>
                <td class="amount">${item.amount}</td>
            </tr>`;
        }).join('');
        
        // Totals
        itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">Subtotal:</td>
                <td class="total-amount">$${parseFloat(quote.subtotal).toFixed(2)}</td>
            </tr>`;
        if (!quote.tax_exempt) {
            itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">Tax (${quote.tax_rate}%):</td>
                <td class="total-amount">$${parseFloat(quote.tax_amount).toFixed(2)}</td>
            </tr>`;
        }
        itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">TOTAL:</td>
                <td class="total-amount">$${parseFloat(quote.total).toFixed(2)}</td>
            </tr>
            <tr class="footer-row">
                <td colspan="4" class="thank-you">Thank you for your business!</td>
            </tr>`;

        let tbdNote = quote.has_tbd ? '<p style="font-size: 12px; margin-top: 20px;"><em>* Note: This quote contains items marked as "TBD". The final total may vary.</em></p>' : '';
        
        // --- ADRESS-LOGIK (NEU) ---
        const addressLines = [];
        // Wenn line1 existiert UND ungleich dem Namen ist, hinzufügen. Sonst überspringen (da Name eh drüber steht).
        if (quote.line1 && quote.line1.trim().toLowerCase() !== (quote.customer_name || '').trim().toLowerCase()) {
            addressLines.push(quote.line1);
        }
        if (quote.line2) addressLines.push(quote.line2);
        if (quote.line3) addressLines.push(quote.line3);
        if (quote.line4) addressLines.push(quote.line4);
        
        const streetBlock = addressLines.join('<br>'); 

        // Ersetzen
        html = html
            .replace('{{LOGO_HTML}}', logoHTML)
            .replace('{{CUSTOMER_NAME}}', quote.customer_name || '')
            .replace('{{CUSTOMER_STREET}}', streetBlock) // Hier kommt der Block rein
            .replace('{{CUSTOMER_CITY}}', quote.city || '')
            .replace('{{CUSTOMER_STATE}}', quote.state || '')
            .replace('{{CUSTOMER_ZIP}}', quote.zip_code || '')
            .replace('{{QUOTE_NUMBER}}', quote.quote_number)
            .replace('{{ACCOUNT_NUMBER}}', quote.account_number || '')
            .replace('{{QUOTE_DATE}}', formatDate(quote.quote_date))
            .replace('{{ITEMS}}', itemsHTML)
            .replace('{{TBD_NOTE}}', tbdNote);

        const browserInstance = await initBrowser();
        const page = await browserInstance.newPage();
        await page.setContent(html, { waitUntil: 'networkidle0', timeout: 60000 });
        const pdf = await page.pdf({
            format: 'Letter', printBackground: true,
            margin: { top: '0.5in', right: '0.5in', bottom: '0.5in', left: '0.5in' }
        });
        await page.close();
        
        res.set({
            'Content-Type': 'application/pdf',
            'Content-Length': pdf.length,
            'Content-Disposition': `attachment; filename="Quote-${quote.quote_number}.pdf"`
        });
        res.end(pdf, 'binary');
        console.log('[PDF] Quote PDF sent successfully');
        
    } catch (error) {
        console.error('[PDF] ERROR:', error);
        res.status(500).json({ error: 'Error generating PDF', details: error.message });
    }
});

app.get('/api/invoices/:id/pdf', async (req, res) => {
    const { id } = req.params;
    console.log(`[INVOICE-PDF] Starting invoice PDF generation for ID: ${id}`);
    
    try {
        // KORRIGIERT: Abfrage von line1-4
        const invoiceResult = await pool.query(`
            SELECT i.*, c.name as customer_name, c.line1, c.line2, c.line3, c.line4, c.city, c.state, c.zip_code, c.account_number
            FROM invoices i
            LEFT JOIN customers c ON i.customer_id = c.id
            WHERE i.id = $1
        `, [id]);
        
        if (invoiceResult.rows.length === 0) {
            return res.status(404).json({ error: 'Invoice not found' });
        }
        
        const invoice = invoiceResult.rows[0];
        const itemsResult = await pool.query(
            'SELECT * FROM invoice_items WHERE invoice_id = $1 ORDER BY item_order',
            [id]
        );
        
        const templatePath = path.join(__dirname, 'templates', 'invoice-template.html');
        let html = await fs.readFile(templatePath, 'utf-8');
        
        let logoHTML = '';
        try {
            const logoPath = path.join(__dirname, 'public', 'uploads', 'company-logo.png');
            const logoData = await fs.readFile(logoPath);
            const logoBase64 = logoData.toString('base64');
            logoHTML = `<img src="data:image/png;base64,${logoBase64}" alt="Company Logo" class="logo logo-size">`;
        } catch (err) {}
        
        let itemsHTML = itemsResult.rows.map(item => {
            let rateFormatted = item.rate;
            if (item.rate.toUpperCase() !== 'TBD' && !item.rate.includes('/')) {
                const rateNum = parseFloat(item.rate.replace(/[^0-9.]/g, ''));
                if (!isNaN(rateNum)) rateFormatted = rateNum.toFixed(2);
            }
            return `
            <tr>
                <td class="qty">${item.quantity}</td>
                <td class="description">${item.description}</td>
                <td class="rate">${rateFormatted}</td>
                <td class="amount">${item.amount}</td>
            </tr>`;
        }).join('');
        
        itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">Subtotal:</td>
                <td class="total-amount">$${parseFloat(invoice.subtotal).toFixed(2)}</td>
            </tr>`;
        if (!invoice.tax_exempt) {
            itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">Tax (${invoice.tax_rate}%):</td>
                <td class="total-amount">$${parseFloat(invoice.tax_amount).toFixed(2)}</td>
            </tr>`;
        }
        itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">TOTAL:</td>
                <td class="total-amount">$${parseFloat(invoice.total).toFixed(2)}</td>
            </tr>
            <tr class="footer-row">
                <td colspan="4" class="thank-you">Thank you for your business!</td>
            </tr>`;

        const authHTML = invoice.auth_code ? `<p style="margin-bottom: 20px; font-size: 13px;"><strong>Authorization:</strong> ${invoice.auth_code}</p>` : '';
        
        // --- ADRESS-LOGIK (NEU) ---
        const addressLines = [];
        if (invoice.line1 && invoice.line1.trim().toLowerCase() !== (invoice.customer_name || '').trim().toLowerCase()) {
            addressLines.push(invoice.line1);
        }
        if (invoice.line2) addressLines.push(invoice.line2);
        if (invoice.line3) addressLines.push(invoice.line3);
        if (invoice.line4) addressLines.push(invoice.line4);
        
        const streetBlock = addressLines.join('<br>');

        html = html
            .replace('{{LOGO_HTML}}', logoHTML)
            .replace('{{CUSTOMER_NAME}}', invoice.customer_name || '')
            .replace('{{CUSTOMER_STREET}}', streetBlock)
            .replace('{{CUSTOMER_CITY}}', invoice.city || '')
            .replace('{{CUSTOMER_STATE}}', invoice.state || '')
            .replace('{{CUSTOMER_ZIP}}', invoice.zip_code || '')
            .replace('{{INVOICE_NUMBER}}', invoice.invoice_number)
            .replace('{{ACCOUNT_NUMBER}}', invoice.account_number || '')
            .replace('{{INVOICE_DATE}}', formatDate(invoice.invoice_date))
            .replace('{{TERMS}}', invoice.terms)
            .replace('{{AUTHORIZATION}}', authHTML)
            .replace('{{ITEMS}}', itemsHTML);

        const browserInstance = await initBrowser();
        const page = await browserInstance.newPage();
        await page.setContent(html, { waitUntil: 'networkidle0', timeout: 60000 });
        const pdf = await page.pdf({
            format: 'Letter', printBackground: true,
            margin: { top: '0.5in', right: '0.5in', bottom: '0.5in', left: '0.5in' }
        });
        await page.close();
        
        res.set({
            'Content-Type': 'application/pdf',
            'Content-Length': pdf.length,
            'Content-Disposition': `attachment; filename="Invoice-${invoice.invoice_number}.pdf"`
        });
        res.end(pdf, 'binary');
        console.log('[INVOICE-PDF] Invoice PDF sent successfully');
        
    } catch (error) {
        console.error('[INVOICE-PDF] ERROR:', error);
        res.status(500).json({ error: 'Error generating PDF', details: error.message });
    }
});


// HTML Debug Endpoints
app.get('/api/quotes/:id/html', async (req, res) => {
    const { id } = req.params;
    
    try {
        // KORREKTUR: Line 1-4 abfragen
        const quoteResult = await pool.query(`
            SELECT q.*, c.name as customer_name, c.line1, c.line2, c.line3, c.line4, c.city, c.state, c.zip_code, c.account_number
            FROM quotes q
            LEFT JOIN customers c ON q.customer_id = c.id
            WHERE q.id = $1
        `, [id]);
        
        if (quoteResult.rows.length === 0) {
            return res.status(404).json({ error: 'Quote not found' });
        }
        
        const quote = quoteResult.rows[0];
        const itemsResult = await pool.query(
            'SELECT * FROM quote_items WHERE quote_id = $1 ORDER BY item_order',
            [id]
        );
        
        const templatePath = path.join(__dirname, 'templates', 'quote-template.html');
        let html = await fs.readFile(templatePath, 'utf-8');
        
        let logoHTML = '';
        try {
            const logoPath = path.join(__dirname, 'public', 'uploads', 'company-logo.png');
            const logoData = await fs.readFile(logoPath);
            const logoBase64 = logoData.toString('base64');
            logoHTML = `<img src="data:image/png;base64,${logoBase64}" alt="Company Logo" class="logo logo-size">`;
        } catch (err) {}
        
        let itemsHTML = itemsResult.rows.map(item => {
            let rateFormatted = item.rate;
            if (item.rate.toUpperCase() !== 'TBD' && !item.rate.includes('/')) {
                const rateNum = parseFloat(item.rate.replace(/[^0-9.]/g, ''));
                if (!isNaN(rateNum)) rateFormatted = rateNum.toFixed(2);
            }
            return `
            <tr>
                <td class="qty">${item.quantity}</td>
                <td class="description">${item.description}</td>
                <td class="rate">${rateFormatted}</td>
                <td class="amount">${item.amount}</td>
            </tr>`;
        }).join('');
        
        itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">Subtotal:</td>
                <td class="total-amount">$${parseFloat(quote.subtotal).toFixed(2)}</td>
            </tr>`;
        if (!quote.tax_exempt) {
            itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">Tax (${quote.tax_rate}%):</td>
                <td class="total-amount">$${parseFloat(quote.tax_amount).toFixed(2)}</td>
            </tr>`;
        }
        itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">TOTAL:</td>
                <td class="total-amount">$${parseFloat(quote.total).toFixed(2)}</td>
            </tr>
            <tr class="footer-row">
                <td colspan="4" class="thank-you">Thank you for your business!</td>
            </tr>`;

        let tbdNote = quote.has_tbd ? '<p style="font-size: 12px; margin-top: 20px;"><em>* Note: This quote contains items marked as "TBD". The final total may vary.</em></p>' : '';
        
        // --- ADRESS LOGIK ---
        const addressLines = [];
        if (quote.line1 && quote.line1.trim().toLowerCase() !== (quote.customer_name || '').trim().toLowerCase()) {
            addressLines.push(quote.line1);
        }
        if (quote.line2) addressLines.push(quote.line2);
        if (quote.line3) addressLines.push(quote.line3);
        if (quote.line4) addressLines.push(quote.line4);
        
        const streetBlock = addressLines.join('<br>');

        html = html
            .replace('{{LOGO_HTML}}', logoHTML)
            .replace('{{CUSTOMER_NAME}}', quote.customer_name || '')
            .replace('{{CUSTOMER_STREET}}', streetBlock)
            .replace('{{CUSTOMER_CITY}}', quote.city || '')
            .replace('{{CUSTOMER_STATE}}', quote.state || '')
            .replace('{{CUSTOMER_ZIP}}', quote.zip_code || '')
            .replace('{{QUOTE_NUMBER}}', quote.quote_number)
            .replace('{{ACCOUNT_NUMBER}}', quote.account_number || '')
            .replace('{{QUOTE_DATE}}', formatDate(quote.quote_date))
            .replace('{{ITEMS}}', itemsHTML)
            .replace('{{TBD_NOTE}}', tbdNote);
            
        res.setHeader('Content-Type', 'text/html');
        res.send(html);
        
    } catch (error) {
        console.error('[HTML] ERROR:', error);
        res.status(500).json({ error: 'Error generating HTML' });
    }
});

app.get('/api/invoices/:id/html', async (req, res) => {
    const { id } = req.params;
    
    try {
        // KORREKTUR: Line 1-4 abfragen
        const invoiceResult = await pool.query(`
            SELECT i.*, c.name as customer_name, c.line1, c.line2, c.line3, c.line4, c.city, c.state, c.zip_code, c.account_number
            FROM invoices i
            LEFT JOIN customers c ON i.customer_id = c.id
            WHERE i.id = $1
        `, [id]);
        
        if (invoiceResult.rows.length === 0) {
            return res.status(404).json({ error: 'Invoice not found' });
        }
        
        const invoice = invoiceResult.rows[0];
        const itemsResult = await pool.query(
            'SELECT * FROM invoice_items WHERE invoice_id = $1 ORDER BY item_order',
            [id]
        );
        
        const templatePath = path.join(__dirname, 'templates', 'invoice-template.html');
        let html = await fs.readFile(templatePath, 'utf-8');
        
        let logoHTML = '';
        try {
            const logoPath = path.join(__dirname, 'public', 'uploads', 'company-logo.png');
            const logoData = await fs.readFile(logoPath);
            const logoBase64 = logoData.toString('base64');
            logoHTML = `<img src="data:image/png;base64,${logoBase64}" alt="Company Logo" class="logo logo-size">`;
        } catch (err) {}
        
        let itemsHTML = itemsResult.rows.map(item => {
            let rateFormatted = item.rate;
            if (item.rate.toUpperCase() !== 'TBD' && !item.rate.includes('/')) {
                const rateNum = parseFloat(item.rate.replace(/[^0-9.]/g, ''));
                if (!isNaN(rateNum)) rateFormatted = rateNum.toFixed(2);
            }
            return `
            <tr>
                <td class="qty">${item.quantity}</td>
                <td class="description">${item.description}</td>
                <td class="rate">${rateFormatted}</td>
                <td class="amount">${item.amount}</td>
            </tr>`;
        }).join('');
        
        itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">Subtotal:</td>
                <td class="total-amount">$${parseFloat(invoice.subtotal).toFixed(2)}</td>
            </tr>`;
        if (!invoice.tax_exempt) {
            itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">Tax (${invoice.tax_rate}%):</td>
                <td class="total-amount">$${parseFloat(invoice.tax_amount).toFixed(2)}</td>
            </tr>`;
        }
        itemsHTML += `
            <tr class="footer-row">
                <td colspan="3" class="total-label">TOTAL:</td>
                <td class="total-amount">$${parseFloat(invoice.total).toFixed(2)}</td>
            </tr>
            <tr class="footer-row">
                <td colspan="4" class="thank-you">Thank you for your business!</td>
            </tr>`;

        const authHTML = invoice.auth_code ? `<p style="margin-bottom: 20px; font-size: 13px;"><strong>Authorization:</strong> ${invoice.auth_code}</p>` : '';
        
        // --- ADRESS LOGIK ---
        const addressLines = [];
        if (invoice.line1 && invoice.line1.trim().toLowerCase() !== (invoice.customer_name || '').trim().toLowerCase()) {
            addressLines.push(invoice.line1);
        }
        if (invoice.line2) addressLines.push(invoice.line2);
        if (invoice.line3) addressLines.push(invoice.line3);
        if (invoice.line4) addressLines.push(invoice.line4);
        
        const streetBlock = addressLines.join('<br>');

        html = html
            .replace('{{LOGO_HTML}}', logoHTML)
            .replace('{{CUSTOMER_NAME}}', invoice.customer_name || '')
            .replace('{{CUSTOMER_STREET}}', streetBlock)
            .replace('{{CUSTOMER_CITY}}', invoice.city || '')
            .replace('{{CUSTOMER_STATE}}', invoice.state || '')
            .replace('{{CUSTOMER_ZIP}}', invoice.zip_code || '')
            .replace('{{INVOICE_NUMBER}}', invoice.invoice_number)
            .replace('{{ACCOUNT_NUMBER}}', invoice.account_number || '')
            .replace('{{INVOICE_DATE}}', formatDate(invoice.invoice_date))
            .replace('{{TERMS}}', invoice.terms)
            .replace('{{AUTHORIZATION}}', authHTML)
            .replace('{{ITEMS}}', itemsHTML);

        res.setHeader('Content-Type', 'text/html');
        res.send(html);
        
    } catch (error) {
        console.error('[HTML] ERROR:', error);
        res.status(500).json({ error: 'Error generating HTML' });
    }
});

// QBO Export Endpoint
app.post('/api/invoices/:id/export', async (req, res) => {
    const { id } = req.params;
    const client = await pool.connect();

    // IDs für deine Items (Labor / Parts)
    const QBO_LABOR_ID = '5'; 
    const QBO_PARTS_ID = '9'; 

    try {
        // 1. Lokale Rechnung laden
        const invoiceRes = await client.query(`
            SELECT i.*, c.qbo_id as customer_qbo_id, c.name as customer_name, c.email
            FROM invoices i
            LEFT JOIN customers c ON i.customer_id = c.id
            WHERE i.id = $1
        `, [id]);

        if (invoiceRes.rows.length === 0) return res.status(404).json({ error: 'Invoice not found' });
        const invoice = invoiceRes.rows[0];

        if (!invoice.customer_qbo_id) {
            return res.status(400).json({ error: `Kunde "${invoice.customer_name}" ist noch nicht mit QBO verknüpft.` });
        }

        // 2. Items laden
        const itemsRes = await client.query('SELECT * FROM invoice_items WHERE invoice_id = $1', [id]);
        const items = itemsRes.rows;

        // 3. QBO Client vorbereiten
        const oauthClient = getOAuthClient();
        const companyId = oauthClient.getToken().realmId;
        const baseUrl = process.env.QBO_ENVIRONMENT === 'production' 
            ? 'https://quickbooks.api.intuit.com' 
            : 'https://sandbox-quickbooks.api.intuit.com';

        // --- SCHRITT 3a: NÄCHSTE NUMMER ERMITTELN ---
        console.log("🔍 Frage QBO nach der letzten Rechnungsnummer...");
        
        // Wir suchen die ZULETZT ERSTELLTE Rechnung
        const lastNumQuery = "SELECT DocNumber FROM Invoice ORDERBY MetaData.CreateTime DESC MAXRESULTS 1";
        const lastNumResponse = await makeQboApiCall({
            url: `${baseUrl}/v3/company/${companyId}/query?query=${encodeURI(lastNumQuery)}`,
            method: 'GET'
        });
        
        const lastNumData = lastNumResponse.getJson ? lastNumResponse.getJson() : lastNumResponse.json;
        let nextDocNumber = null;

        if (lastNumData.QueryResponse && lastNumData.QueryResponse.Invoice && lastNumData.QueryResponse.Invoice.length > 0) {
            const lastDocNumberStr = lastNumData.QueryResponse.Invoice[0].DocNumber;
            // Versuchen, die Nummer zu parsen (Entfernt Buchstaben, behält Zahlen)
            const lastNum = parseInt(lastDocNumberStr.replace(/[^0-9]/g, ''), 10);
            
            if (!isNaN(lastNum)) {
                nextDocNumber = (lastNum + 1).toString();
                console.log(`✅ Letzte Nummer war ${lastDocNumberStr}. Neue Nummer wird: ${nextDocNumber}`);
            }
        }

        // Fallback: Wenn QBO leer ist oder Parsing fehlschlägt, nimm die lokale Nummer
        if (!nextDocNumber) {
            console.log("⚠️ Konnte keine Nummer aus QBO ermitteln. Verwende lokale Nummer.");
            nextDocNumber = invoice.invoice_number;
        }
        // -------------------------------------------

        
        // 4. QBO JSON bauen
        const lineItems = items.map(item => {
            const rate = parseFloat(item.rate.replace(/[^0-9.]/g, '')) || 0;
            const amount = parseFloat(item.amount.replace(/[^0-9.]/g, '')) || 0;
            
            const itemRefId = item.qbo_item_id || QBO_PARTS_ID; 
            const itemRefName = itemRefId == QBO_LABOR_ID ? "Labor:Labor" : "Parts:Parts";

            return {
                "DetailType": "SalesItemLineDetail",
                "Amount": amount,
                "Description": item.description, 
                "SalesItemLineDetail": {
                    "ItemRef": { "value": itemRefId, "name": itemRefName },
                    "UnitPrice": rate,
                    "Qty": parseFloat(item.quantity) || 1
                }
            };
        });

        const qboInvoicePayload = {
            "CustomerRef": { "value": invoice.customer_qbo_id },
            
            // HIER SETZEN WIR DIE ERMITTELTE NUMMER EIN
            "DocNumber": nextDocNumber,
            
            "TxnDate": invoice.invoice_date.toISOString().split('T')[0],
            "Line": lineItems,
            "CustomerMemo": { "value": invoice.auth_code ? `Auth: ${invoice.auth_code}` : "" },
            
            // Status auf "Verschickt" setzen
            "EmailStatus": "EmailSent",
            "BillEmail": { "Address": invoice.email || "" }
        };

        console.log(`📤 Sende Rechnung an QBO (DocNumber: ${nextDocNumber})...`);
        
        const createResponse = await makeQboApiCall({
            url: `${baseUrl}/v3/company/${companyId}/invoice`,
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify(qboInvoicePayload)
        });

        const responseData = createResponse.getJson ? createResponse.getJson() : createResponse.json;
        // Check auf Unterobjekt "Invoice"
        const qboInvoice = responseData.Invoice || responseData;

        console.log("🔍 FULL QBO RESPONSE (ID):", qboInvoice.Id);

        if (!qboInvoice.Id) {
            console.error("FULL RESPONSE DUMP:", JSON.stringify(responseData, null, 2));
            throw new Error("QBO hat keine ID zurückgegeben.");
        }

        console.log(`✅ QBO Rechnung erstellt! ID: ${qboInvoice.Id}, DocNumber: ${qboInvoice.DocNumber}`);

        // 6. DB Update: Wir speichern AUCH die QBO-Nummer, damit wir wissen, wie sie drüben heißt
        await client.query(
            `UPDATE invoices SET qbo_id = $1, qbo_sync_token = $2, qbo_doc_number = $3, invoice_number = $3 WHERE id = $4`,
            [qboInvoice.Id, qboInvoice.SyncToken, qboInvoice.DocNumber, id]
        );

        // Wir geben die neue Nummer zurück, damit das Frontend Bescheid weiß
        res.json({ success: true, qbo_id: qboInvoice.Id, qbo_doc_number: qboInvoice.DocNumber });

    } catch (error) {
        console.error("QBO Export Error:", error);
        let errorDetails = error.message;
        if (error.response?.data?.Fault?.Error?.[0]) {
             errorDetails = error.response.data.Fault.Error[0].Message + ": " + error.response.data.Fault.Error[0].Detail;
        }
        res.status(500).json({ error: "QBO Export failed: " + errorDetails });
    } finally {
        client.release();
    }
});

app.get('/api/qbo/overdue', async (req, res) => {
    try {
        // Datum vor 30 Tagen berechnen
        const date = new Date();
        date.setDate(date.getDate() - 30);
        const dateStr = date.toISOString().split('T')[0];

        console.log(`🔍 Suche in QBO nach unbezahlten Rechnungen fällig vor ${dateStr}...`);

        // Query: Offene Rechnungen, deren Fälligkeitsdatum älter als 30 Tage ist
        const query = `SELECT DocNumber, TxnDate, DueDate, Balance, CustomerRef, TotalAmt FROM Invoice WHERE Balance > '0' AND DueDate < '${dateStr}' ORDERBY DueDate ASC`;
        
        const oauthClient = getOAuthClient();
        const companyId = oauthClient.getToken().realmId;
        const baseUrl = process.env.QBO_ENVIRONMENT === 'production' 
            ? 'https://quickbooks.api.intuit.com' 
            : 'https://sandbox-quickbooks.api.intuit.com';

        // makeQboApiCall kümmert sich um den Refresh, falls nötig!
        const response = await makeQboApiCall({
            url: `${baseUrl}/v3/company/${companyId}/query?query=${encodeURI(query)}`,
            method: 'GET'
        });
        
        const data = response.getJson ? response.getJson() : response.json;
        const invoices = data.QueryResponse?.Invoice || [];
        
        console.log(`✅ ${invoices.length} überfällige Rechnungen gefunden.`);
        res.json(invoices);

    } catch (error) {
        console.error("QBO Report Error:", error);
        res.status(500).json({ error: error.message });
    }
});
// Schritt 1: User klickt "Authorize" → Redirect zu Intuit
app.get('/auth/qbo', (req, res) => {
    const client = getOAuthClient();
    const authUri = client.authorizeUri({
        scope: [OAuthClient.scopes.Accounting],
        state: 'intuit-qbo-auth'
    });
    console.log('🔗 Redirecting to QBO Authorization:', authUri);
    res.redirect(authUri);
});

// Schritt 2: Intuit redirected zurück mit Code → Token holen
app.get('/auth/qbo/callback', async (req, res) => {
    const client = getOAuthClient();
    try {
        const authResponse = await client.createToken(req.url);
        console.log('✅ QBO Authorization erfolgreich!');
        saveTokens();
        
        // Redirect zurück zur App (Settings Tab)
        res.redirect('/#settings');
    } catch (e) {
        console.error('❌ QBO Authorization fehlgeschlagen:', e);
        res.status(500).send(`
            <h2>QBO Authorization Failed</h2>
            <p>${e.message || e}</p>
            <a href="/">Zurück zur App</a>
        `);
    }
});

// Status-Check Endpoint (für die UI)
app.get('/api/qbo/status', (req, res) => {
    try {
        const client = getOAuthClient();
        const token = client.getToken();
        const hasToken = !!(token && token.refresh_token);
        res.json({ 
            connected: hasToken,
            realmId: token?.realmId || null
        });
    } catch (e) {
        res.json({ connected: false });
    }
});

app.post('/api/qbo/import-unpaid', async (req, res) => {
    const dbClient = await pool.connect();
    
    try {
        const oauthClient = getOAuthClient();
        const companyId = oauthClient.getToken().realmId;
        const baseUrl = process.env.QBO_ENVIRONMENT === 'production' 
            ? 'https://quickbooks.api.intuit.com' 
            : 'https://sandbox-quickbooks.api.intuit.com';

        // 1. Alle unbezahlten Rechnungen aus QBO holen
        //    Balance > '0' = noch nicht vollständig bezahlt
        //    MAXRESULTS 1000 = sicherheitshalber hoch setzen
        console.log('📥 QBO Import: Lade unbezahlte Rechnungen...');
        
        const query = "SELECT * FROM Invoice WHERE Balance > '0' ORDERBY DocNumber ASC MAXRESULTS 1000";
        const response = await makeQboApiCall({
            url: `${baseUrl}/v3/company/${companyId}/query?query=${encodeURI(query)}`,
            method: 'GET'
        });

        const data = response.getJson ? response.getJson() : response.json;
        const qboInvoices = data.QueryResponse?.Invoice || [];
        
        console.log(`📋 ${qboInvoices.length} unbezahlte Rechnungen in QBO gefunden.`);

        if (qboInvoices.length === 0) {
            return res.json({ 
                success: true, 
                imported: 0, 
                skipped: 0, 
                skippedNoCustomer: 0,
                message: 'Keine unbezahlten Rechnungen in QBO gefunden.' 
            });
        }

        // 2. Lokale Kunden laden (die mit QBO verknüpft sind)
        const customersResult = await dbClient.query(
            'SELECT id, qbo_id, name, taxable FROM customers WHERE qbo_id IS NOT NULL'
        );
        const customerMap = new Map();
        customersResult.rows.forEach(c => customerMap.set(c.qbo_id, c));

        // 3. Bereits importierte QBO-Rechnungen ermitteln (nach qbo_id)
        const existingResult = await dbClient.query(
            'SELECT qbo_id FROM invoices WHERE qbo_id IS NOT NULL'
        );
        const existingQboIds = new Set(existingResult.rows.map(r => r.qbo_id));

        // 4. Import durchführen
        let imported = 0;
        let skipped = 0;
        let skippedNoCustomer = 0;
        const skippedCustomerNames = [];

        await dbClient.query('BEGIN');

        for (const qboInv of qboInvoices) {
            const qboId = String(qboInv.Id);
            
            // Bereits importiert? → Überspringen
            if (existingQboIds.has(qboId)) {
                skipped++;
                continue;
            }

            // Kunde lokal vorhanden?
            const customerQboId = String(qboInv.CustomerRef?.value || '');
            const localCustomer = customerMap.get(customerQboId);
            
            if (!localCustomer) {
                skippedNoCustomer++;
                const custName = qboInv.CustomerRef?.name || 'Unbekannt';
                if (!skippedCustomerNames.includes(custName)) {
                    skippedCustomerNames.push(custName);
                }
                continue;
            }

            // Werte aus QBO-Rechnung extrahieren
            const docNumber = qboInv.DocNumber || '';
            const txnDate = qboInv.TxnDate || new Date().toISOString().split('T')[0];
            const syncToken = qboInv.SyncToken || '';
            
            // Terms aus QBO mappen (SalesTermRef)
            let terms = 'Net 30';
            if (qboInv.SalesTermRef?.name) {
                terms = qboInv.SalesTermRef.name;
            }

            // Tax: Prüfen ob TaxLine vorhanden
            const taxAmount = qboInv.TxnTaxDetail?.TotalTax || 0;
            const taxExempt = taxAmount === 0;
            
            // Subtotal berechnen (Total - Tax)
            const total = parseFloat(qboInv.TotalAmt) || 0;
            const subtotal = total - taxAmount;
            const taxRate = subtotal > 0 && !taxExempt ? (taxAmount / subtotal * 100) : 8.25;

            // Memo als auth_code (falls vorhanden)
            const authCode = qboInv.CustomerMemo?.value || '';

            // Rechnung einfügen
            const invoiceResult = await dbClient.query(
                `INSERT INTO invoices 
                 (invoice_number, customer_id, invoice_date, terms, auth_code, 
                  tax_exempt, tax_rate, subtotal, tax_amount, total,
                  qbo_id, qbo_sync_token, qbo_doc_number)
                 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13)
                 RETURNING id`,
                [docNumber, localCustomer.id, txnDate, terms, authCode,
                 taxExempt, taxRate, subtotal, taxAmount, total,
                 qboId, syncToken, docNumber]
            );

            const localInvoiceId = invoiceResult.rows[0].id;

            // Line Items importieren
            const lines = qboInv.Line || [];
            let itemOrder = 0;

            for (const line of lines) {
                // Nur SalesItemLineDetail-Zeilen (keine SubTotalLine etc.)
                if (line.DetailType !== 'SalesItemLineDetail') continue;

                const detail = line.SalesItemLineDetail || {};
                const qty = String(detail.Qty || 1);
                const rate = String(detail.UnitPrice || 0);
                const amount = String(line.Amount || 0);
                const description = line.Description || '';
                
                // Item-Typ ermitteln (Labor=5, Parts=9)
                const itemRefValue = detail.ItemRef?.value || '9';
                const itemRefName = (detail.ItemRef?.name || '').toLowerCase();
                let qboItemId = '9'; // Default: Parts
                if (itemRefValue === '5' || itemRefName.includes('labor')) {
                    qboItemId = '5';
                }

                await dbClient.query(
                    `INSERT INTO invoice_items 
                     (invoice_id, quantity, description, rate, amount, item_order, qbo_item_id)
                     VALUES ($1, $2, $3, $4, $5, $6, $7)`,
                    [localInvoiceId, qty, description, rate, amount, itemOrder, qboItemId]
                );
                itemOrder++;
            }

            imported++;
            console.log(`  ✅ Importiert: #${docNumber} (${localCustomer.name}) - $${total}`);
        }

        await dbClient.query('COMMIT');

        const message = [
            `${imported} Rechnungen importiert.`,
            skipped > 0 ? `${skipped} bereits vorhanden (übersprungen).` : '',
            skippedNoCustomer > 0 ? `${skippedNoCustomer} übersprungen (Kunde nicht verknüpft: ${skippedCustomerNames.join(', ')}).` : ''
        ].filter(Boolean).join(' ');

        console.log(`📥 QBO Import abgeschlossen: ${message}`);

        res.json({ 
            success: true, 
            imported, 
            skipped, 
            skippedNoCustomer,
            skippedCustomerNames,
            message 
        });

    } catch (error) {
        await dbClient.query('ROLLBACK');
        console.error('❌ QBO Import Error:', error);
        res.status(500).json({ error: 'Import fehlgeschlagen: ' + error.message });
    } finally {
        dbClient.release();
    }
});

// Mark invoice as paid
app.patch('/api/invoices/:id/mark-paid', async (req, res) => {
    const { id } = req.params;
    const { paid_date } = req.body; // Optional: explizites Datum, sonst heute
    
    try {
        const dateToUse = paid_date || new Date().toISOString().split('T')[0];
        const result = await pool.query(
            'UPDATE invoices SET paid_date = $1, updated_at = CURRENT_TIMESTAMP WHERE id = $2 RETURNING *',
            [dateToUse, id]
        );
        
        if (result.rows.length === 0) {
            return res.status(404).json({ error: 'Invoice not found' });
        }
        
        console.log(`💰 Invoice #${result.rows[0].invoice_number} als bezahlt markiert (${dateToUse})`);
        res.json(result.rows[0]);
    } catch (error) {
        console.error('Error marking invoice as paid:', error);
        res.status(500).json({ error: 'Error marking invoice as paid' });
    }
});

// Mark invoice as unpaid
app.patch('/api/invoices/:id/mark-unpaid', async (req, res) => {
    const { id } = req.params;
    
    try {
        const result = await pool.query(
            'UPDATE invoices SET paid_date = NULL, updated_at = CURRENT_TIMESTAMP WHERE id = $1 RETURNING *',
            [id]
        );
        
        if (result.rows.length === 0) {
            return res.status(404).json({ error: 'Invoice not found' });
        }
        
        console.log(`↩️ Invoice #${result.rows[0].invoice_number} als unbezahlt markiert`);
        res.json(result.rows[0]);
    } catch (error) {
        console.error('Error marking invoice as unpaid:', error);
        res.status(500).json({ error: 'Error marking invoice as unpaid' });
    }
});

app.patch('/api/invoices/:id/reset-qbo', async (req, res) => {
    const { id } = req.params;
    
    try {
        const result = await pool.query(
            `UPDATE invoices 
             SET qbo_id = NULL, qbo_sync_token = NULL, qbo_doc_number = NULL, invoice_number = NULL, 
                 updated_at = CURRENT_TIMESTAMP 
             WHERE id = $1 RETURNING *`,
            [id]
        );
        
        if (result.rows.length === 0) {
            return res.status(404).json({ error: 'Invoice not found' });
        }
        
        console.log(`🔄 Invoice ID ${id} QBO-Verknüpfung zurückgesetzt`);
        res.json(result.rows[0]);
    } catch (error) {
        console.error('Error resetting QBO link:', error);
        res.status(500).json({ error: 'Error resetting QBO link' });
    }
});




// Start server and browser
async function startServer() {
    await initBrowser();
    
    app.listen(PORT, () => {
        console.log(`Quote System running on port ${PORT}`);
    });
}

startServer();

// Graceful shutdown
process.on('SIGTERM', async () => {
    if (browser) {
        await browser.close();
    }
    await pool.end();
    process.exit(0);
});