CRBT-Team/Purplet

// Purplet runtime for Vercel Edge Functions
import { handleInteraction } from '../generated-build';
import { hexStringToUint8Array } from 'purplet/internal';
import { sign } from 'tweetnacl';

const te = new TextEncoder();

export const config = {
  runtime: 'experimental-edge',
};

export default async function (req) {
  const signature = req.headers.get('X-Signature-Ed25519');
  const timestamp = req.headers.get('X-Signature-Timestamp');
  const body = await req.text();

  if (!signature || !timestamp || !body) {
    return new Response('Bad request.', { status: 400 });
  }

  if (
    !sign.detached.verify(
      te.encode(timestamp + body),
      hexStringToUint8Array(signature),
      hexStringToUint8Array(env.DISCORD_PUBLIC_KEY)
    )
  ) {
    return new Response('Bad request signature.', { status: 401 });
  }

  return new Response(JSON.stringify(await handleInteraction(JSON.parse(body))));
}