import { Request, Response } from 'express';
import { stripe } from '../lib/stripe';
import Stripe from 'stripe';

export async function handleWebhook(
  req: Request,
  res: Response
): Promise<void> {
  if (!stripe) {
    res.json({ received: true });
    return;
  }

  const sig = req.headers['stripe-signature'];
  const webhookSecret = process.env.STRIPE_WEBHOOK_SECRET;

  if (!webhookSecret) {
    console.error('STRIPE_WEBHOOK_SECRET is not set');
    res.status(500).json({ error: 'Webhook secret not configured' });
    return;
  }

  let event: Stripe.Event;

  try {
    event = stripe.webhooks.constructEvent(
      req.body,
      sig as string,
      webhookSecret
    );
  } catch (err) {
    const errorMessage = err instanceof Error ? err.message : 'Unknown error';
    console.error('Webhook signature verification failed:', errorMessage);
    res.status(400).send(`Webhook Error: ${errorMessage}`);
    return;
  }

  // Handle the event
  switch (event.type) {
    case 'checkout.session.completed':
      const session = event.data.object as Stripe.Checkout.Session;
      console.log('Payment successful for session:', session.id);
      // Here you can:
      // - Save the payment to your database
      // - Send confirmation email
      // - Grant access to course/service
      // - Update user account
      break;
    default:
      console.log(`Unhandled event type ${event.type}`);
  }

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