/**
 * Stripe — Transaction history
 * ----------------------------
 * Returns the payment records written by the webhook (the server-side source of
 * truth). Reads from Vercel KV when connected; returns an empty list otherwise
 * so the frontend degrades gracefully and falls back to its local record.
 *
 * GET /api/payments/transactions  ->  { transactions: [...] }
 */

export default async function handler(req, res) {
    if (req.method !== 'GET') {
        return res.status(405).json({ error: 'Method not allowed' });
    }

    try {
        const { kv } = await import('@vercel/kv');
        const raw = await kv.lrange('payments:transactions', 0, 199);
        const transactions = (raw || []).map((item) =>
            typeof item === 'string' ? JSON.parse(item) : item
        );
        return res.status(200).json({ transactions });
    } catch {
        // KV not configured — the frontend will use its local record instead.
        return res.status(200).json({ transactions: [] });
    }
}