import express from 'express';
import cors from 'cors';
import Stripe from 'stripe';
import dotenv from 'dotenv';

dotenv.config();

const app = express();
const port = process.env.PORT || 3001;

// Initialize Stripe
const stripe = new Stripe(process.env.STRIPE_SECRET_KEY);

// Middleware
app.use(cors({
  origin: process.env.FRONTEND_URL || 'http://localhost:5173',
}));
app.use(express.json());

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

// Create Stripe Checkout Session
app.post('/api/checkout', async (req, res) => {
  try {
    const { orderData } = req.body;
    
    // Validate required fields
    if (!orderData?.contact?.email || !orderData?.contact?.name) {
      return res.status(400).json({ error: 'Name and email are required' });
    }

    // Create Stripe Checkout Session
    const session = await stripe.checkout.sessions.create({
      payment_method_types: ['card'],
      mode: 'payment',
      customer_email: orderData.contact.email,
      line_items: [
        {
          price_data: {
            currency: 'eur',
            product_data: {
              name: 'Website in 48h',
              description: `${orderData.websiteType} | ${orderData.style} | ${orderData.theme === 'dark' ? 'Dunkel' : 'Hell'}`,
              images: ['https://webklar.de/og-image.png'], // Optional
            },
            unit_amount: 19900, // 199€ in cents
          },
          quantity: 1,
        },
      ],
      metadata: {
        customerName: orderData.contact.name,
        customerCompany: orderData.contact.company || '',
        customerPhone: orderData.contact.phone || '',
        websiteType: orderData.websiteType,
        style: orderData.style,
        theme: orderData.theme,
        colorPrimary: orderData.colors?.primary || '#0A400C',
        colorSecondary: orderData.colors?.secondary || '#819067',
        colorAccent: orderData.colors?.accent || '#B1AB86',
        customReferenceUrl: orderData.customInput?.referenceUrl || '',
        customDescription: orderData.customInput?.description || '',
      },
      success_url: `${process.env.FRONTEND_URL || 'http://localhost:5173'}/success?session_id={CHECKOUT_SESSION_ID}`,
      cancel_url: `${process.env.FRONTEND_URL || 'http://localhost:5173'}/konfigurator`,
    });

    res.json({ 
      sessionId: session.id,
      url: session.url 
    });

  } catch (error) {
    console.error('Stripe error:', error);
    res.status(500).json({ 
      error: 'Failed to create checkout session',
      details: error.message 
    });
  }
});

// Verify session (for success page)
app.get('/api/session/:sessionId', async (req, res) => {
  try {
    const session = await stripe.checkout.sessions.retrieve(req.params.sessionId);
    
    res.json({
      id: session.id,
      status: session.payment_status,
      customerEmail: session.customer_email,
      amountTotal: session.amount_total,
      metadata: session.metadata,
    });
  } catch (error) {
    console.error('Session verification error:', error);
    res.status(404).json({ error: 'Session not found' });
  }
});

// Stripe Webhook (for production)
app.post('/api/webhook', express.raw({ type: 'application/json' }), async (req, res) => {
  const sig = req.headers['stripe-signature'];
  const webhookSecret = process.env.STRIPE_WEBHOOK_SECRET;

  if (!webhookSecret) {
    console.warn('Webhook secret not configured');
    return res.status(400).send('Webhook secret not configured');
  }

  try {
    const event = stripe.webhooks.constructEvent(req.body, sig, webhookSecret);

    switch (event.type) {
      case 'checkout.session.completed':
        const session = event.data.object;
        console.log('✅ Payment successful:', session.id);
        // TODO: Save order to database, send confirmation email, etc.
        break;
      
      case 'payment_intent.payment_failed':
        console.log('❌ Payment failed:', event.data.object.id);
        break;
        
      default:
        console.log(`Unhandled event type: ${event.type}`);
    }

    res.json({ received: true });
  } catch (error) {
    console.error('Webhook error:', error.message);
    res.status(400).send(`Webhook Error: ${error.message}`);
  }
});

app.listen(port, () => {
  console.log(`\n🚀 Server running on http://localhost:${port}`);
  console.log(`\n📋 Endpoints:`);
  console.log(`   GET  /api/health`);
  console.log(`   POST /api/checkout`);
  console.log(`   GET  /api/session/:sessionId`);
  console.log(`   POST /api/webhook\n`);
});