import { redirect, type RequestHandler } from '@sveltejs/kit';

export const GET: RequestHandler = async ({ url }) => {
  // The redirect target after a successful login.
  // Default to root; can be overridden via ?next= for deep links.
  const next = url.searchParams.get('next');
  const safeNext = next && next.startsWith('/') && !next.startsWith('//') ? next : '/';
  const stateRedirect = encodeURIComponent(safeNext);

  // Lazy import to avoid loading the OAuth module unless we need it.
  const { buildAuthorizeUrl } = await import('$lib/server/auth');
  const authorizeUrl = buildAuthorizeUrl(stateRedirect);
  throw redirect(302, authorizeUrl);
};