// Stripe Webhook Handler (Backend Required)
// This needs to run on a server, not in Base44 frontend

const stripe = require('stripe')(process.env.STRIPE_SECRET_KEY);
const express = require('express');
const app = express();

// Webhook endpoint
app.post('/webhook', express.raw({type: 'application/json'}), async (req, res) => {
  const sig = req.headers['stripe-signature'];
  const webhookSecret = process.env.STRIPE_WEBHOOK_SECRET;
  
  let event;
  
  try {
    event = stripe.webhooks.constructEvent(req.body, sig, webhookSecret);
  } catch (err) {
    return res.status(400).send(`Webhook Error: ${err.message}`);
  }

  // Handle the event
  switch (event.type) {
    case 'checkout.session.completed':
      const session = event.data.object;
      // Update Base44: Mark subscription as active
      await updateProviderSubscription(session.customer, {
        subscription_status: 'active',
        stripe_customer_id: session.customer,
        stripe_subscription_id: session.subscription
      });
      break;
      
    case 'invoice.payment_succeeded':
      const invoice = event.data.object;
      // Update payment dates
      await updateProviderPayment(invoice.customer, {
        last_payment_date: new Date().toISOString(),
        next_billing_date: new Date(invoice.lines.data[0].period.end * 1000).toISOString()
      });
      break;
      
    case 'invoice.payment_failed':
      const failedInvoice = event.data.object;
      // Mark as past due and notify
      await updateProviderSubscription(failedInvoice.customer, {
        subscription_status: 'past_due'
      });
      await sendPaymentFailedEmail(failedInvoice.customer_email);
      break;
      
    case 'customer.subscription.deleted':
      const subscription = event.data.object;
      // Downgrade to basic plan
      await updateProviderSubscription(subscription.customer, {
        subscription_status: 'cancelled',
        pricing_tier: 'basic'
      });
      break;
  }

  res.json({received: true});
});

// Helper functions to update Base44
async function updateProviderSubscription(stripeCustomerId, updates) {
  // Call Base44 API to update provider
  const response = await fetch('https://api.base44.com/entities/Provider', {
    method: 'PATCH',
    headers: {
      'Authorization': `Bearer ${process.env.BASE44_API_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      filter: { stripe_customer_id: stripeCustomerId },
      updates: updates
    })
  });
  return response.json();
}

app.listen(3000, () => console.log('Webhook server running on port 3000'));