index.ts

import SumUp from "@sumup/sdk";

const apiKey = process.env.SUMUP_API_KEY;
const merchantCode = process.env.SUMUP_MERCHANT_CODE;

if (!apiKey) {
  console.error("Missing SUMUP_API_KEY env var.");
  process.exit(1);
}

if (!merchantCode) {
  console.error("Missing SUMUP_MERCHANT_CODE env var.");
  process.exit(1);
}

const client = new SumUp({ apiKey });

const port = Number(process.env.PORT) || 8080;

function parseAmount(value: unknown) {
  const amount = Number(value);
  if (!Number.isFinite(amount) || amount <= 0) {
    return null;
  }

  return {
    currency: "EUR",
    minor_unit: 2,
    value: Math.round(amount * 100),
  };
}

Bun.serve({
  port,
  async fetch(req) {
    const url = new URL(req.url);
    const segments = url.pathname.split("/").filter(Boolean);

    if (segments.length === 1 && segments[0] === "readers") {
      if (req.method === "GET") {
        try {
          const readers = await client.readers.list(merchantCode);
          return Response.json(readers);
        } catch (error) {
          console.error("Failed to list readers:", error);
          return Response.json(
            { error: "failed to list readers" },
            { status: 500 },
          );
        }
      }

      if (req.method !== "POST") {
        return new Response("Not found", { status: 404 });
      }

      let payload: { pairing_code?: string; name?: string };
      try {
        payload = (await req.json()) as {
          pairing_code?: string;
          name?: string;
        };
      } catch {
        return Response.json({ error: "invalid json" }, { status: 400 });
      }

      const pairingCode = String(payload.pairing_code ?? "").trim();
      const name = String(payload.name ?? "").trim();
      if (!pairingCode || !name) {
        return Response.json(
          { error: "pairing_code and name are required" },
          { status: 400 },
        );
      }

      try {
        const reader = await client.readers.create(merchantCode, {
          pairing_code: pairingCode,
          name,
        });

        return Response.json(reader, { status: 201 });
      } catch (error) {
        console.error("Failed to create reader:", error);
        return Response.json(
          { error: "failed to create reader" },
          { status: 500 },
        );
      }
    }

    if (
      segments.length === 3 &&
      segments[0] === "readers" &&
      segments[2] === "checkout"
    ) {
      if (req.method !== "POST") {
        return new Response("Not found", { status: 404 });
      }

      let payload: { amount?: number };
      try {
        payload = (await req.json()) as { amount?: number };
      } catch {
        return Response.json({ error: "invalid json" }, { status: 400 });
      }

      const totalAmount = parseAmount(payload.amount);
      if (!totalAmount) {
        return Response.json(
          { error: "amount must be a positive number" },
          { status: 400 },
        );
      }

      const readerId = segments[1];
      if (!readerId) {
        return Response.json(
          { error: "readerId is required" },
          { status: 400 },
        );
      }

      try {
        const checkout = await client.readers.createCheckout(
          merchantCode,
          readerId,
          {
            total_amount: totalAmount,
            description: "Card reader checkout",
          },
        );

        return Response.json(checkout, { status: 201 });
      } catch (error) {
        console.error("Failed to create reader checkout:", error);
        return Response.json(
          { error: "failed to create reader checkout" },
          { status: 500 },
        );
      }
    }

    return new Response("Not found", { status: 404 });
  },
});

console.log(`Bun server listening on http://localhost:${port}`);