import Stripe from 'stripe';

function getStripe(): Stripe | null {
	if (!process.env.STRIPE_SECRET_KEY) return null;
	return new Stripe(process.env.STRIPE_SECRET_KEY);
}

export async function createDonationCheckout(params: {
	amount: number;
	donorEmail?: string;
	petId?: number;
	petName?: string;
	successUrl: string;
	cancelUrl: string;
}): Promise<string | null> {
	const stripe = getStripe();
	if (!stripe) return null;

	const session = await stripe.checkout.sessions.create({
		payment_method_types: ['card'],
		mode: 'payment',
		customer_email: params.donorEmail,
		line_items: [{
			price_data: {
				currency: 'usd',
				product_data: {
					name: params.petName
						? `Donation for ${params.petName}`
						: 'Donation'
				},
				unit_amount: params.amount
			},
			quantity: 1
		}],
		metadata: {
			type: 'donation',
			petId: params.petId?.toString() || ''
		},
		success_url: params.successUrl,
		cancel_url: params.cancelUrl
	});

	return session.url;
}

export async function createAdoptionFeeCheckout(params: {
	amount: number;
	petId: number;
	petName: string;
	adopterEmail: string;
	successUrl: string;
	cancelUrl: string;
}): Promise<string | null> {
	const stripe = getStripe();
	if (!stripe) return null;

	const session = await stripe.checkout.sessions.create({
		payment_method_types: ['card'],
		mode: 'payment',
		customer_email: params.adopterEmail,
		line_items: [{
			price_data: {
				currency: 'usd',
				product_data: {
					name: `Adoption Fee — ${params.petName}`
				},
				unit_amount: params.amount
			},
			quantity: 1
		}],
		metadata: {
			type: 'adoption_fee',
			petId: params.petId.toString()
		},
		success_url: params.successUrl,
		cancel_url: params.cancelUrl
	});

	return session.url;
}

export function constructWebhookEvent(
	body: string,
	signature: string
): Stripe.Event | null {
	const stripe = getStripe();
	if (!stripe || !process.env.STRIPE_WEBHOOK_SECRET) return null;

	return stripe.webhooks.constructEvent(
		body,
		signature,
		process.env.STRIPE_WEBHOOK_SECRET
	);
}