// Netlify Function für PayPal Order
// Erfordert PAYPAL_CLIENT_ID und PAYPAL_CLIENT_SECRET als Umgebungsvariablen

const fetch = require('node-fetch');

// PayPal OAuth Token holen
async function getPayPalAccessToken() {
	const auth = Buffer.from(
		`${process.env.PAYPAL_CLIENT_ID}:${process.env.PAYPAL_CLIENT_SECRET}`
	).toString('base64');

	const response = await fetch('https://api-m.sandbox.paypal.com/v1/oauth2/token', {
		method: 'POST',
		headers: {
			'Content-Type': 'application/x-www-form-urlencoded',
			Authorization: `Basic ${auth}`,
		},
		body: 'grant_type=client_credentials',
	});

	const data = await response.json();
	return data.access_token;
}

// PayPal Order erstellen
async function createPayPalOrder(accessToken, amount, isRecurring, priceId, coffeeSize) {
	const url = isRecurring
		? 'https://api-m.sandbox.paypal.com/v1/billing/plans'
		: 'https://api-m.sandbox.paypal.com/v2/checkout/orders';

	if (isRecurring) {
		// Vereinfachtes Beispiel für ein Abonnement
		// In einer echten Anwendung sollten Sie Pläne vorab erstellen
		const planData = {
			name: `BaunTown Monthly ${coffeeSize}`,
			description: `Monthly ${coffeeSize} support for BaunTown (${amount}€)`,
			type: 'FIXED',
			payment_definitions: [
				{
					name: `Monthly ${coffeeSize}`,
					type: 'REGULAR',
					frequency: 'MONTH',
					frequency_interval: '1',
					amount: {
						value: amount,
						currency: 'EUR',
					},
					cycles: '0',
				},
			],
			merchant_preferences: {
				return_url: `${process.env.URL || 'http://localhost:3000'}/support-success`,
				cancel_url: `${process.env.URL || 'http://localhost:3000'}/support-cancel`,
			},
		};

		const response = await fetch(url, {
			method: 'POST',
			headers: {
				'Content-Type': 'application/json',
				Authorization: `Bearer ${accessToken}`,
			},
			body: JSON.stringify(planData),
		});

		return response.json();
	} else {
		// Normale einmalige Zahlung
		const orderData = {
			intent: 'CAPTURE',
			purchase_units: [
				{
					amount: {
						currency_code: 'EUR',
						value: amount,
					},
					description: `${coffeeSize} für BaunTown (${amount}€)`,
					custom_id: priceId,
				},
			],
			application_context: {
				return_url: `${process.env.URL || 'http://localhost:3000'}/support-success?amount=${amount}&type=${isRecurring ? 'recurring' : 'one-time'}&provider=paypal&coffeeSize=${encodeURIComponent(coffeeSize)}`,
				cancel_url: `${process.env.URL || 'http://localhost:3000'}/support-cancel`,
			},
		};

		const response = await fetch(url, {
			method: 'POST',
			headers: {
				'Content-Type': 'application/json',
				Authorization: `Bearer ${accessToken}`,
			},
			body: JSON.stringify(orderData),
		});

		return response.json();
	}
}

exports.handler = async (event, context) => {
	// CORS Headers
	const headers = {
		'Access-Control-Allow-Origin': '*',
		'Access-Control-Allow-Headers': 'Content-Type',
		'Access-Control-Allow-Methods': 'POST, OPTIONS',
	};

	// Handle OPTIONS request (CORS preflight)
	if (event.httpMethod === 'OPTIONS') {
		return {
			statusCode: 200,
			headers,
			body: '',
		};
	}

	try {
		// Request-Body parsen
		const data = JSON.parse(event.body);
		const { amount, isRecurring, priceId, coffeeSize } = data;

		// PayPal Access Token holen
		const accessToken = await getPayPalAccessToken();

		// Order oder Plan erstellen mit zusätzlichen Metadaten
		const paypalResponse = await createPayPalOrder(
			accessToken,
			amount,
			isRecurring,
			priceId,
			coffeeSize
		);

		return {
			statusCode: 200,
			headers,
			body: JSON.stringify(paypalResponse),
		};
	} catch (error) {
		console.error('PayPal error:', error);

		return {
			statusCode: 500,
			headers,
			body: JSON.stringify({
				error: {
					message: error.message || 'Internal server error',
				},
			}),
		};
	}
};